X-ray generation and detection

[ali_asadzadeh]

Hi,
Since I was a kid I was wondering how they generate and capture x-ray for imaging human body? I have seen some projects on youtube, but I want to know is it possible to use normal image sensors with some modification to build a DIY camera for ourselves, so we could see inside things! like seeing under the balls of a BGA or human tissue! any Idea about generating and capturing x-ray cheaply, would be highly welcomed since we have these little powerful cortex Devices, I think it's time to make something cool

[Gyro]

An extremely dangerous thing to attempt... Anything to do with imaging (or exposure of) human flesh! 

[ali_asadzadeh]

All of us knows it's very dangerous! Do you know something and are you willing to share?

[NiHaoMike]

Surplus dental Xray - fairly cheap and actually designed to be "safe" for use on humans.

[Gyro]

All of us knows it's very dangerous! Do you know something and are you willing to share?

Not really, there are various things on the web, using HV triodes in cold cathode mode etc. but nothing that would be acceptable in the context of the human body (even in the vicinity without shielding). Medical X-Rays use 'hard X-rays' (much higher tube voltage, 100kV plus?) and specifically filter out all the damaging and useless 'soft' X-rays. Unfortunately I think the home-brew solutions only produce soft x-rays, tube supply in the 20kV range.

As NiHaoMike points out, there are surplus dental x-rays which probably have an 'acceptable' dosage with one short exposure every few months but that's unlikely to be very satisfying for you.

There are knowledgeable folks around here who own X-ray machines and will probably provide advice on PCB, BGA etc. but I think you're going to have to reign in you ambitions on organic things.

[Neukyhm]

I built one using a PC case. Generating x-rays is easy, I just used a 2n3055 driver, a flyback, the 2C2S vacuum tube and a x-ray cassette.

[ahbushnell]

Hi,
Since I was a kid I was wondering how they generate and capture x-ray for imaging human body? I have seen some projects on youtube, but I want to know is it possible to use normal image sensors with some modification to build a DIY camera for ourselves, so we could see inside things! like seeing under the balls of a BGA or human tissue! any Idea about generating and capturing x-ray cheaply, would be highly welcomed since we have these little powerful cortex Devices, I think it's time to make something cool

Very dangerous.  In California X-ray sources are licensed. 

I worked with 60 kV electron guns and those things cranked out the xrays.  It took a lot of work to shield. 

[MosherIV]

  All of us knows it's very dangerous! Do you know something and are you willing to share?

Think about it from a practicle measurable point of view.

Do you have anything that can reliably detect X-rays?
Do you know what level of exposure is safe?
Can your measurement equipement measure to the accuracy and resolution required to determine safe exposure?

You need to be able to detect/measure X-rays before you look into generating them.

Doing it any other way means you may expose yourself without knowing it.
The effects of radiation may not be immediate, it may take decades before the damaging effects start to show

Do you really want to take the risk?

[ali_asadzadeh]

Thanks for sharing!
Neukyhm would you please share more info with us,my bigger problem is measuring the x-ray not generating it for now, do you know some way of detecting and capturing x-ray images say 1 frame per second? how did you got the images?

[Neukyhm]

Thanks for sharing!
Neukyhm would you please share more info with us,my bigger problem is measuring the x-ray not generating it for now, do you know some way of detecting and capturing x-ray images say 1 frame per second? how did you got the images?

The easiest way to detect x-rays is using a Geiger counter, I got one for ~100€ from GQ Electronics. Another way to detect is covering your phone's camera and point it to a source. In photo/video mode, the screen should show some pixels turning on due to the x-rays activating the camera's pixels.

In order to take pictures like the one I uploaded, you need a camera (like the Nikon D300 I'm using) configured for long exposure, and a x-ray cassette, I'm using a Fujifilm Speed Green and this support I designed for it

The x-rays will make the cassette light, you just take a picture to it for a few seconds.

[Distelzombie]

I always found many people are overly anxious about nuclear radiation. So I guess that is my part here.
I am collecting radioactive stuff. Uranium Ores, Radium paste for clock hands, tritium vials, uranium glazed pottery, americium sources for ionisation chambers (e.g. smoke detectors), I guess also radon gas, but that is just coincidence, and other stuff


You are able by just calculating power input, output and the power lost to nearly get the amount of x-ray that tube would emit. Probably even WAY too much since it is also emitting a ton of IR.
So it is "safe" even without a geiger counter.

[james_s]

By far the cheapest, safest and most readily available good quality xray source are surplus dental heads. Given a larger than usual tube to subject distance you can get very good quality images of objects much larger than the teeth they are designed to image. Typically these run in the 60-70kVp range and have an aluminum filter to block the lower energy emission that only contributes to absorbed dose without generating any useful image. The big advantage of a dental head is it is a sealed unit containing the tube and HV transformer immersed in insulating oil or SF6 with the whole assembly well shielded.

For detection the cheapest and simplest method is to use film in a cassette. Xray cassettes consist of a light-proof case with phosphor screens that convert xrays to visible light greatly reducing the exposure required vs bare film. It's possible to point a camera at one of these screens to get a poor man's digital xray sensor however the sensitivity is quite low so I would certainly not use it to image anything living.

Be *very* careful if you attempt to play around with this stuff, xrays are seriously dangerous. They are high energy photons that pass through many objects, they can scatter, they affect your body like very powerful UV except instead of sun burning the surface they pass all the way through, you really don't want to sunburn your internal organs.

[Distelzombie]

"be very careful" simply boils down to: Know the µSv, lower exposure time of yourself, stay well inside generally advised maximum exposure levels.
You can make X-ray pictures of yourself. There is nothing against it! Just don't do it stupidly.

[james_s]

Careful making blanket statements like that, I don't think it's legal to xray anyone, including yourself in many parts of the world. Even if you know what you're doing, I highly suggest only experimenting with non-living subjects and be aware of any local laws and regulations. Radiation is serious stuff, few words invoke more irrational fear in people and there is the potential for real danger. You should absolutely not underestimate that, you really don't want there to be any chance whatsoever that you have exposed someone to radiation with your experiments.

[Neukyhm]

Careful making blanket statements like that, I don't think it's legal to xray anyone, including yourself in many parts of the world. Even if you know what you're doing, I highly suggest only experimenting with non-living subjects and be aware of any local laws and regulations. Radiation is serious stuff, few words invoke more irrational fear in people and there is the potential for real danger. You should absolutely not underestimate that, you really don't want there to be any chance whatsoever that you have exposed someone to radiation with your experiments.

I agree with that. When I was designing my machine, I made it remote controlled of course. I connect it to a PC, then I leave the room and activate it via remote desktop. Doing that and also using a geiger counter, you are safe.

[ebastler]

[...] like seeing under the balls of a BGA or human tissue! any Idea about generating and capturing x-ray cheaply, would be highly welcomed since we have these little powerful cortex Devices, I think it's time to make something cool

Your approach to researching and designing X-ray equipment is to ask (pardon me) naive questions on an electronics forum.
Conclusion: You should probably not mess with X-ray.

And what do the Cortex processors have to do with this?? Or were you referring to your own, built-in cortex? Yes, that can be a powerful device too, but I don't recommend irradiating it with a homebrew X-ray machine... 

[SiliconWizard]

An extremely dangerous thing to attempt... Anything to do with imaging (or exposure of) human flesh! 

It is, and as someone else mentioned, it's also regulated in most countries in the world. You can't have an x-ray equipement without a proper license and a (usually) yearly control.

Doing that without a valid license may even get you penal sanctions in some countries.

[ebastler]

By the way:

___________________________________
You can order parts from www.ASiDesigner.com
we are a wire-based company

No, I can't. There is a significant language barrier. 

[Distelzombie]

I knew "Just don't do it stupidly." wouldn't be enough for "some people".
I don't care about legal systems outside of mine. You should know if it is legal. That is not my responsibility. I don't have to make y'all aware of that.
I am here to lower the fear of nuclear radiation to a more rational state, and you come again with:
"Radiation is serious stuff, few words invoke more irrational fear in people and there is the potential for real danger. You should absolutely not underestimate that..." How am I invoking irrational fears?!

[BFX]

Are you guys really experienced in this stuff? I think its more dangerous like high voltage power!
I'm working for siemens x-ray medical nowadays siemens healthineers.
There is very very careful about radiation. And I seen some accidents!       

[Distelzombie]

More or equally dangerous than instant-death-probability? Seriously?! That is just extremely over the top. 
You can stand directly infront of a medical x-ray machine for, it's a guess, month before you would die from it. (Directly) Try that with high-voltage.
Not even the elephants-foot is as dangerous as touching high voltage wires in a way that the current goes through your heart. This is just ridiculous.

A corporation or concern is always very careful because they have to comply to what their insurer says. They don't want to pay millions per worker because they made the mistake to not fully educate them about the risks of radiation: If you fear it extremely, you'll be extremely careful. They don't care if this level of fear is rational or not, if it safes them from lawsuits. I guess.

[MosherIV]

Are you guys really experienced in this stuff?

Me, personally - nope, not much. I worked for a company servicing industrial X-ray machines.
I was not allowd into the service area let alone the x-ray test chamber when the red testing light was on, despite the chamber room being lead lined.
The technician doing the work had annual check ups.

Hence, I suggect a quantative (measurable) aporoach.
Just becuase some geiger counters can detect X-rays, not all geiger counters detect X-rays. Make sure the one you get can and is calibrated.
Are they calibrated for X-rays?
What is the safe level of exposure?
Do people realise X-rays can go through walls ?

(Fyi The industrial X-ray machines were for X-raying metal pipes. I do not know what the procedure was for X-raying  pipes but I would not want to be anywhere near it !)

You can stand directly infront of a medical x-ray machine for, it's a guess, month before you would die from it

You can suffer substantial damage to you DNA without any symptons.
The first you will know about it is either deformed children or cancer.

[Gyro]

Yes, there are things much worse than instant death.

[ebastler]

You can stand directly infront of a medical x-ray machine for, it's a guess, month before you would die from it.

Sure. Just make sure that you don't switch it on for too long.
And drink plenty of water, eat your vitamins, and take a nap every now and then.

 

Seriously though: A typical medical X-ray exam gives you a radiation exposure of a few mSv.  1000 of those will cause most severe radiation disease, with 100% mortality within 14 days. Even one tenth of that dose will already cause 10% mortality over a 30 day period. So if you really meant operating a medical X-ray continuously and standing in the beam path, your estimate is ridiculously far off.

[james_s]

A geiger counter is not the most effective way to measure xray exposure. It will count xray photons but it tells you nothing about the energy level which has a significant effect on dosage. What you really want is an ion chamber survey meter. Still the best way to experiment with this sort of thing is to avoid any exposure at all. Use the tube in the original shielded head, mount it pointing down toward the subject, on the ground floor of a building so nobody will be below it. Don't ever attempt to image anything living, radiation exposure can be cumulative and there is no level considered absolutely safe.

[BFX]

More or equally dangerous than instant-death-probability? Seriously?! That is just extremely over the top. 
You can stand directly infront of a medical x-ray machine for, it's a guess, month before you would die from it. (Directly) Try that with high-voltage.
Not even the elephants-foot is as dangerous as touching high voltage wires in a way that the current goes through your heart. This is just ridiculous.

A corporation or concern is always very careful because they have to comply to what their insurer says. They don't want to pay millions per worker because they made the mistake to not fully educate them about the risks of radiation: If you fear it extremely, you'll be extremely careful. They don't care if this level of fear is rational or not, if it safes them from lawsuits. I guess.

Do you know difference between high voltage and very high voltage? Obviously not!
Did you ever seen some test areas for x-ray products ? Obviously also not! There is this amount od lead, that you cant imagine. It should be always on basemen because of weight and also nobody in x-ray path.

[Distelzombie]

Think about the people working there, this is important: Every day they are exposed to radiation. You forgot to include time in your judgement. Because:
Just like in everything else: The dose makes the poison. (And in electronics it's the current, you should know that.)

You can walk in the room with the elephants-foot, take a look and live the rest of your life happy and well. Heck, the guy that posed in there with a guitar is still alive, with only minor issues! He was in there for hours over month!
That's just for comparison, because your equipment could never reach such high dose rates - except your not working with medical equipment or are shining several sources at you at the same time.

Also: YOU don't know what high-voltage is: High voltage is defined by the DOE Electrical Safety Guidelines as over 600 volts. Are you telling me that can't kill a person in a second or less? (Well I considered 120 AC to be high-voltage, but this is even better for my case, isn't it?)
Do you know how much radiation is necessary to kill you in a second? Ever visited the inside of Fukushima Daiichi Nuclear Power Plant reactors? What was is it... 15 Sievert? Well that could kill you pretty fast. A second would probably still be hard to reach in there.

You're wrong.

[TopLoser]

Congratulations on being the first person I’ve ever blocked on EEV

[BFX]

Distelzombie

Do you know that this blog can be read also by young people without any experience or knowledge and you tell them that X-Ray is really nothing so dangerous? Because this don't kill you right now?
Are you all right?

That's last comment to you.   

[james_s]

I'd rather die instantly from electrocution than suffer a slow and painful death from radiation poisoning. It's really nothing to take lightly. You can absolutely get a serious radiation burn or die from even a small dental xray tube with a sufficiently long exposure. Yes people do react irrationally regarding radiation but that doesn't mean there is not genuine danger.

[BravoV]

Lots of noises, lack of essentials.


Reality check on OP as he started ....

.... any Idea about generating and capturing x-ray cheaply

Define cheap ? $1 ? $10 ? $100 ? $1000 ?

As this will be a good start on how feasible to continue with your idea.

Also what have you done to gather info about "minimum" gadget even DIY to start ? Say HV stuffs ? Vacuum tube ? or access/salvage used medical equipments such as dental x-ray ?

NO ! You can not sourced/made x-ray things easily from kitchen's stuffs.

..... since we have these little powerful cortex Devices, I think it's time to make something cool

What cortex ? Leave this alone, use high power CPU from PC, even this does NOT have anything to do with x-ray.


Again, how is your capability to source/buy rare stuffs for these in your place ?


Otherwise this is becoming another wasted energy/time for contributors.

[ebastler]

Otherwise this is becoming another wasted energy/time for contributors.

I'm afraid that has already occurred. I'm out of here...

[Distelzombie]

This is so ridiculous! Stop teaching the Young wrong facts to induce fear in them so that they'll never even consider to take a job in this area.
We don't live in a dystopia, BFX!
I am not even saying "yea build your own x-ray, it's nothing to worry about"! Are you delusional? I said this would be stupid! I said go and educate yourself before trying to!
This forum is by definition of a scientific nature. You are talking as if you are a religious anti-rad fanatic that doesn't want anyone to know the truth! This is so wrong, I'm furious! That's very biased!

Ignore what you don't want to hear is never a solution. Does he know that blocking me just removes my posts in his viewport? Probably not what he intended, judging by all the context here.

James I never said there is no danger. This is just your imagination.


This is Orwellian!
I thought there will be the usual wrong idea about radioactivity to find in this thread. But this is horrible! You are fanatics: I bring up counterarguments to steer the thread away from "You're going to die if you do this" and immediately get surrounded and beaten up, then shunned.
Maybe go back a little, breath, and read again what I wrote, with all the nuances, from the start, but this time try not to fall into fanatic mode or biasing again, OK?

How can there be so much distrust in the abilities of a reader? You're not even making a fool or yourselves, you are also disrespecting the readers by patronizing them.

Can't blame me for this thread going downhill. I was just supporting it.  I'm all about experimenting with radioactivity. Tell the fanatics.

[Twoflower]

...
NO ! You can not sourced/made x-ray things easily from kitchen's stuffs.
...

Actually you can. Just roll of a scotch tape in vacuum: https://www.technologyreview.com/s/411085/x-rays-made-with-scotch-tape/ OK, producing a sufficient vacuum with kitchen stuff might be problematic.

From my uneducated view here: The way ali_asadzadeh asked the question I would suggest that he should first spend some time to educate himself in this topic. By do so he would gain a certain knowledge that will answer most of his questions. And produced an awareness to handle the most critical parts. From what I see this is not a learning by doing topic.

[BravoV]

From what I see this is not a learning by doing topic.

This is just another lazy and bored question dumped into this forum, without expecting & "honoring" people who helped, and unfortunately, lots of generous contributors jumped in without realizing this thread is just going no where.


Its like ....

Hi there, I have a lot "used" good stiff coaxial lines/pipes salvaged from spectrum analayzers, also I can CNC aluminium block for RF voodoo, and also I salvaged tons of good RF stuffs and components.

Can someone help me to design and build a "CHEAP" 60GHz spectrum signal analyzer ? Oh, btw .. I'm just a hobbyist and yesterday I just learned how to bias a transistor, and I'm quite confident and comfortable with Arduino and LCD touch screen for the SA display, as the latest R&S signal analyzer inspired me. 

I guess we can "easily" predict how this kind of request for help, ends up.

My example for request is even better, as I already have the stuffs to begin with. 



May be its just me ... my 2 cents.

[ali_asadzadeh]

Thank you all for all your concerns and warnings.

Define cheap ? $1 ? $10 ? $100 ? $1000 ?

I have a budget of around 5000USD for this project, it's not high, neither it's not low. I want to use it for doing this project in my spare time.

Oh, btw .. I'm just a hobbyist and yesterday I just learned how to bias a transistor,

FIY I'm designing very cool and creative stuff about 20 years for now, I have lots of experience in PCB design more than 300 projects till today, also a lot of coding experience specially in Real-time designs including Doing DSP algorithms, And I have very good knowledge in various CPU architectures like MCS-5, AVR,XMEGA, Cortex M from more than 5 Manufacturers. Please do not worry about my lack of experience in designing solid industrial, licensable stuff !

Let's reorder the things I should do, suppose that I have a dentist friend who will lend me his dental X-ray machine for an 1 hour a weak! and suppose that I can make things be done remotely in another room and for our safety I would start with normal things to examine, like seeing the balls of my cortex BGA chip


First of all I should design something to capture the X-ray Images, I remember that once I was in a PCBA factory, they had an x-ray machine that could capture 30 frame per second X-ray images, there was a X-Y controlled machine that could travel all along the boards and you could inspect the defects in assembling the parts like ball's of a BGA in real time, There was a joystick and you could move the camera everywhere you wanted in the machine, So what are the options to capture X-ray images in real time? is there cheap way of using regular CMOS censors , for example from omnivision to detect the X-ray images?

[Neukyhm]

So what are the options to capture X-ray images in real time?

If your x-rays source is powerful enough and you are using a good camera, you just need a x-ray cassette like the one I'm using. It will turn on with visible light, if that light's intensity is high, you can just record it with a video camera to have real time x-ray images.

[ahbushnell]

Yes, there are things much worse than instant death.

Slow death from cancer?

[sdouble]

the detection of nuclear radiation is my field of expertise.
I agree that there is nothing "magic" behind radiation. It's all physics and well understood nowadays.
However, for uneducated people, it can really be dangerous. Even soft x-rays are not something we should play with.
I saw so many dentists doing some crazy things. Dentists can't be called "uneducated" but still....
 

[CopperCone]

Square law aside, how much lead sheilding does something like a dental head require?

And how does the spread from an xray look like? Can it be imagined like a incandescent bulb?

[Neukyhm]

Square law aside, how much lead sheilding does something like a dental head require?

It can be calculated according to an exponent law and NIST attenuation coefficients for lead

I remember to be like a 90% attenuation/mm for 70keV rays, not sure about that.

[Wolfram]

Square law aside, how much lead sheilding does something like a dental head require?

It can be calculated according to an exponent law and NIST attenuation coefficients for lead

I remember to be like a 90% attenuation/mm for 70keV rays, not sure about that.

An x-ray tube emits a continuous spectrum of x-ray energies, up to the supply voltage, so the attenuation needs to be calculated for the entire spectrum and then integrated for the total dose rate. Attached is an example of an attenuation calculation for an aluminium filter. It is generally easier to find a source of attenuation tables for a given tube voltage and lead thickness.

[james_s]

With a $5k budget this project should be easy. That's enough to buy a functional xray generator and a decent sized xray intensifier (fluoroscope). You might be able to find a used flat panel sensor in that range though I would expect it to need a bit of work. Another option is a CR system, these use a film-less cassette that temporarily stores a latent image on a special phosphor then you run it through a machine that scans it into a digital image and clears the phosphor for reuse. You might even find a complete machine like those for inspecting parcels, those are about as safe as xray machines get as they are designed for relatively unskilled operators.

[TurboTom]

Actually, the "soft" radiation is the more problematic variety, at least concering medical X-Ray. It gets absorbed more or less completely by the tissue, doing its damage, and not contributing to the image. That's why (most) medical X-Ray tubes/heads utilize aluminium filters to block the soft radiation. One exception is mammography equipment. These machines work with rather soft X-ray of 20...30kV for obvious reasons but that's also why this kind of diagnostics is discussed quite controversely. Hard X-Rays (60...120kV) pass through most soft tissue and don't cause too much damage there (of course, relatively speaking).

It's not safe to consider standing "behind" the X-ray apparatus is safe. The radiation is being back-scattered and objects exposed to X radiation tend to fluorece on characteristic (longer) X-ray wavelengths (that's the way nowadays materials are analyzed easily, quickly and non-destructively). The radiation intensity, even of a small X-Ray source, is surprisingly high. I've got an industrial, low power CW head that runs just on several tens of microamps (65kV) but it completely saturates my geiger counter if placed in front of the aperture and causes readings I've never seen before if located behind the apparatus. And that's a lead-shielded assembly.

Just to refer to @Distelzombie's statement of the safety standing in front of an X-Ray tube for a month... (powered I assume), this is a gross underestimation of its danger. The typical exposure during an X-Ray examination ranges from several tens of microsieverts to a few millisieverts, the duration of the exposure lies between a few hundred milliseconds to several seconds. Let's assume the exposure will be about 1mSv per second. Which means that within one hour you collect 3.6Sv. At that dose, you've got at least a 50% risk of death within a few weeks and severe radiation sickness and permanent health problems for sure. No stationary anode X-Ray tube will "survive" this torture thermally but who would dare to fight the competition against the tube? 

And now, just to give you an idea what a medical X-Ray head of a dental panoramic machine (Gendex Orthoralix 9200) looks like, I attached a few photos. I got the head less the tube and modified it to implant a Phider / Nago GF181-0.6-125-65 that I was able to source inexpensively. Will that be safe by itself? No way!  Do I know what I'm doing? I think so. At least I've got some equipment to help me estimate the danger emanating form the device (if I will ever operate it). Anyway, it's quite interesting technology and not too difficult to replicate (if someone really wants to experiment with this). Most important, do your homework, think first and think again, and if you are not sure of what you're doing, don't do it! Better safe than sorry.

Cheers,
Thomas

[Wolfram]

Just to refer to @Distelzombie's statement of the safety standing in front of an X-Ray tube for a month... (powered I assume), this is a gross underestimation of its danger. The typical exposure during an X-Ray examination ranges from several tens of microsieverts to a few millisieverts, the duration of the exposure lies between a few hundred milliseconds to several seconds. Let's assume the exposure will be about 1mSv per second. Which means that within one hour you collect 3.6Sv. At that dose, you've got at least a 50% risk of death within a few weeks and severe radiation sickness and permanent health problems for sure. No stationary anode X-Ray tube will "survive" this torture thermally but who would dare to fight the competition against the tube? 

Spot on. To expand on this, a typical rotating anode medical tube can dissipate around 2 kW for CW use, mostly through blackbody radiation. At this power level, the dose rate is around 1.5 Sv/hr at a distance of 3 m from the focal spot, a distance which allows the beam to expand to cover a significant part of your body. For shorter exposures, these tubes can do peaks of over 50 Sv/hr at 3 meters!

Nice dental x-ray head, that looks like an orthopantomographic one. Those are made for higher voltages (90 - 100 kV typical, vs. 60 - 70) and higher doses than normal dental x-ray heads. I've dismantled another GE high frequency head and it also had the middle-fed voltage multiplier.

[sdouble]

I still feel unconfortable with all those details given here about something which is (or should be) parsec away the DIY world

[Neukyhm]

I still feel unconfortable with all those details given here about something which is (or should be) parsec away the DIY world

Totally disagree. Why? If you are aware of the danger and you know how to be away of it, I would recommend going for this stuff.

That is, of course, supposing you know what you are doing.

For example, researching and experimenting with x-rays has brought me the possibility to work with my teachers at my university in some interesting projects.

Knowledge should never be forbidden to those that are willing to learn, including the dangerous stuff.

[james_s]

The potential danger and exotic nature is also part of what makes it so fascinating. People have had dangerous hobbies forever, I'm not sure a small xray setup is really that much more dangerous than fast cars, motorcycles, guns, or numerous other dangerous items people play with. The key is to not be careless.

[amyk]

The potential danger and exotic nature is also part of what makes it so fascinating. People have had dangerous hobbies forever, I'm not sure a small xray setup is really that much more dangerous than fast cars, motorcycles, guns, or numerous other dangerous items people play with. The key is to not be careless.

The other thing that hasn't been mentioned is the OP's country of origin. I'm pretty sure people there have a perception of risk very different from someone in California, for example, or Ukraine.

[ali_asadzadeh]

If your x-rays source is powerful enough and you are using a good camera, you just need a x-ray cassette like the one I'm using. It will turn on with visible light, if that light's intensity is high, you can just record it with a video camera to have real time x-ray images.

Thanks, how long does the x-ray cassette hold the visible light? I mean does it vanish as soon as we turn the x-ray off? because I want to be able to get real time images, also does this cassette have a life time over the exposure? and what sort of prices should I expect? where can I get one? Are they DIY Doable?

That's enough to buy a functional xray generator and a decent sized xray intensifier (fluoroscope)

what's the difference between the fluoroscope and X-ray cassette? are they DIY manufactural? what sort of prices should I expect? Where should I expect to get one?

Also I have this question too, does x-ray act like a spot light? How should we scale things in the image, for example we should place the light source farther away the object to cover more area of the object? What about the placement of the CMOS image sensor?

TurboTom, thanks for sharing? Did you extract the schematic for the lamp? It looks very simple, what is the lamp part number? Also what are the caps and resistors ratings? What frequency does the convertor works? And what’s the generated voltage? How we should control the voltage?

Regarding the Cortex Usage for this project, some of the more powerful ones have image sensor interface and the LCD controller along some encoder inputs, so they are quite capable of doing robotics x-ray imaging systems.

Again thanks for sharing!

[Neukyhm]

If your x-rays source is powerful enough and you are using a good camera, you just need a x-ray cassette like the one I'm using. It will turn on with visible light, if that light's intensity is high, you can just record it with a video camera to have real time x-ray images.

Thanks, how long does the x-ray cassette hold the visible light? I mean does it vanish as soon as we turn the x-ray off? because I want to be able to get real time images, also does this cassette have a life time over the exposure? and what sort of prices should I expect? where can I get one? Are they DIY Doable?

Depending on the cassette, it will be fast or slow, I mean, it will hold the image or not. You want real time images so you want a fast cassette, the Fuji speed green is fast, I bought it for 20€ on eBay.

[ali_asadzadeh]

Neukyhm thanks for the info,

What about the X-ray lamp and the circuit to make voltages and controlling it, would you please share your info with us?

[Neukyhm]

Neukyhm thanks for the info,

What about the X-ray lamp and the circuit to make voltages and controlling it, would you please share your info with us?

I already said, the source is a 2C2S tube, and the circuit is a regular 2n3055 flyback driver you can find on the internet.

[Wolfram]

A "fast" cassette does not describe how long the afterglow of the phosphor is, it describes the x-ray sensitivity of the cassette. A fast screen allows a shorter exposure time, but at a lower resolution. All modern screens are based on Gd2O2S:Tb phosphor, and the main difference is the thickness of the coating. A Fast cassette will have a thicker coating and therefore emit more light, but the resulting image will be less sharp due to internal scattering of the light inside the phosphor layer.

[Distelzombie]

Just to refer to @Distelzombie's statement of the safety standing in front of an X-Ray tube for a month... (powered I assume), this is a gross underestimation of its danger. The typical exposure during an X-Ray examination ranges from several tens of microsieverts to a few millisieverts, the duration of the exposure lies between a few hundred milliseconds to several seconds. Let's assume the exposure will be about 1mSv per second. Which means that within one hour you collect 3.6Sv. At that dose, you've got at least a 50% risk of death within a few weeks and severe radiation sickness and permanent health problems for sure. No stationary anode X-Ray tube will "survive" this torture thermally but who would dare to fight the competition against the tube? 

Spot on. To expand on this, a typical rotating anode medical tube can dissipate around 2 kW for CW use, mostly through blackbody radiation. At this power level, the dose rate is around 1.5 Sv/hr at a distance of 3 m from the focal spot, a distance which allows the beam to expand to cover a significant part of your body. For shorter exposures, these tubes can do peaks of over 50 Sv/hr at 3 meters!

Nice dental x-ray head, that looks like an orthopantomographic one. Those are made for higher voltages (90 - 100 kV typical, vs. 60 - 70) and higher doses than normal dental x-ray heads. I've dismantled another GE high frequency head and it also had the middle-fed voltage multiplier.

I didn't really meant a big one for chest x-rays and I didn't specify the distance, but you're right! It wasn't a very good sentence and the info is of.
I don't remember anymore, but there was a reason why I put that "Directly" after it:
"You can stand directly infront of a medical x-ray machine for, it's a guess, month before you would die from it. (Directly)"
Let's say it's a little less stupid a sentence as the one BFX wrote about high voltage being equally dangerous - but it's still stupid. I'm not denying that.

Still can't see enough reason to block me. I don't understand TopLoser. Was it the "You're wrong"? Well, don't be a pussy. 

I still feel unconfortable with all those details given here about something which is (or should be) parsec away the DIY world

To ban talking about something makes me feel uncomfortable.

[james_s]

Film cassettes don't have any appreciable phosphor persistence, as soon as the source is off the glow stops. As was mentioned up there somewhere, there is a tradeoff between sensitivity and image quality. The best images are produced by mammo cassettes which have a single phosphor screen and the film has a single sided emulsion. Most general diagnostic cassettes and film are double sided, the film has emulsion on both sides and the cassette sandwiches it between two phosphor screens. The grain size of the phosphor and film has a similar relationship, finer grain produces a more detailed image but requires a longer exposure.

Since I was only interested in imaging inanimate objects that don't squirm and aren't affected by absorbed dose, I prefer mammo film and cassettes. Industrial film like Agfa Structurix is also nice, it is low sensitivity but some variants have a very fine grain and the emulsion has a protective layer so it does not scratch nearly as easily as medical diagnostic film.

[Distelzombie]

There are digital "phosphor"screens. Maybe you can get your hands on one of these in defect condition. Repair them and they'll probably be a very good substitution for real phosphor.

[james_s]

Good luck with that, even in untested/non-working condition digital flat panel detectors are $$$. I think about the cheapest I've seen one sell for is around $1100. Brand new they're around $20k for low end.

There is also the CR system which stores a latent image on some kind of special phosphor cassette which is scanned by a laser in a special machine to digitize the image.

[Old Don]

Hello, Darwin Awards? Guess what, I've a good one for you! There was this guy and he wanted to Xray himself......

[Distelzombie]

Why thank him for that, ebastler? He's just making fun of the TO and everyone with this hobby. And it's not even funny.
Fun fact: You're getting x-rayed constantly. Without the need to stand in front of a device.

[ebastler]

Why thank him for that, ebastler? He's just making fun of the TO and everyone with this hobby. And it's not even funny.
Fun fact: You're getting x-rayed constantly. Without the need to stand in front of a device.

The serious advice in this thread has not been effective, so maybe poking fun at the OP will?
I stand by my original advice to the OP:

Your approach to researching and designing X-ray equipment is to ask (pardon me) naive questions on an electronics forum.
Conclusion: You should probably not mess with X-ray.

If you can't even formulate a proper Google query, digest the results, and then ask informed questions: Keep your hands off this!

[Distelzombie]

You're "patronizing him to stay stupid". You think you'll be able to talk him out of it? Because ... why? Because you think you are more capable of grasping the sheer horrible nature of this experiment than he is? Why?
Maybe come up with an equivalent experiment that won't kill him if he makes that one mistake, that even a middle-schooler would be able to avoid! Like giving a child, who found a real gun, a BB-gun instead. He'll learn what it takes to shoot a gun and he'll be happy.

This kind of entitlement that enables you to say: "I know what's best for you" is the most DISGUSTING thing one can display - if you don't give sensible advise together with it, or maybe an alternative way to pursue in this hobby - or if don't even have proper knowledge about the topic. In fact, I don't think entitlement will ever be not-disgusting.

Damn it, why is everybody OK to talk about high voltage equipment, but is reluctant to do so about x-ray machinery, huh? I know: Because you understand high-voltage! You know how to handle it - you are even experienced maybe. But you are also afraid of what you don't understand:
You assume they don't know how to handle those machinery, just because you yourself don't know or because of the underlying problem in this analogue: They've hammered the safety measures you need to follow to stay alive while working with high-voltage into you, and you don't think about those measures very much because they have seeped into your nature. So you don't mention them all the time while talking about it.
-> Why do you assume they didn't go through a training like that themselves, but for nuclear radiation instead?

You didn't even had the thought that he might have the same expertise as the usual Rad-Con, but knows nothing about electronics, did you? Maybe that's the reason he is here to ask about it: Because he just doesn't know how to do that one part of it, doesn't mean he knows nothing about it at all! He never asked what x-rays are, did he? 

Don't get me wrong! It is really great that you are concerned about his well being. But after the third page of patronizing, you should just stop being obnoxious.

This post is for everyone to reflect upon. Not just for ebastler.
And I am frustrated and disappointed again, so it sounds a little heated.

EDIT: If this is not the case then tell me. I really want to understand why you would do this constantly, guys. It's the only explanation I have.

[ebastler]

This post is for everyone to reflect upon. Not just for ebastler.
And I am frustrated and disappointed again, so it sounds a little heated.

EDIT: If this is not the case then tell me. I really want to understand why you would do this constantly, guys. It's the only explanation I have.

I can only speak for myself here. My rationale is pretty simple:

Yes, I believe that it is possible to conduct experiments with X-ray safely, even in a home lab. And they may be interesting and rewaring. But that requires learning, planning, analytical thought, design, risk assessment, ... 

But here we have a person who appears unwilling and/or unable to invest any of these. He instead asks naive questions on an electronics forum, without giving the slightest hint of pre-work, or of following up (by further reading) on various technical suggestions that were given in this thread. Instead, just more "show me" and "tell me".

This is scary. I don't see how the OP expects to build a safe system, unless he had someone physically by his side watching his every step -- because he shows no inclination at all to study beyond the "now show me my next step" level. I feel compelled to tell the OP, and others who may read this thread now or later, that this is not the way to approach such a topic. (And yes, the same holds true for high voltage, high pressure, explosives, ... experiments, in my book).

[Neukyhm]

"I know what's best for you" is the most DISGUSTING thing one can display - if you don't give sensible advise together with it, or maybe an alternative way to pursue in this hobby - or if don't even have proper knowledge about the topic. In fact, I don't think entitlement will ever be not-disgusting.

You are right.

He instead asks naive questions on an electronics forum, without giving the slightest hint of pre-work, or of following up (by further reading) on various technical suggestions that were given in this thread. Instead, just more "show me" and "tell me".

You are also right.

See? You both are right! let's take a beer.

I have to say (because I have experienced that too) that I also find disgusting when I ask something in a forum and people start treating me like an idiot or saying don't do that because I haven't done that but still I know it's dangerous.

I have built a x-ray machine (with spare parts, very low power etc, not my best creation) but I could build it wasting a month looking for information on the internet (I mean, I didn't even have to ask in forums) because if you keep looking you'll find it. There are somethings you won't find such as methods to do something, that is when you come here to ask experienced people that will tell you "Do it THIS way", but if you are looking for someone to tell you just "Do this" then I think it's better to keep learning things on the internet before asking.

EDIT: it is very difficult to know how much OP user knows about x-rays

[MosherIV]

Don't get me wrong! It is really great that you are concerned about his well being. But after the third page of patronizing, you should just stop being obnoxious.

This post is for everyone to reflect upon. Not just for ebastler.
And I am frustrated and disappointed again, so it sounds a little heated.

EDIT: If this is not the case then tell me. I really want to understand why you would do this constantly, guys. It's the only explanation I have.

Firstly, let me say that I am trying to be neutral and constructive about the issue.

Yes, some have made flippant remarks but I do not think they have been obnoxious.

Distelzombie, you have made some statements that are questionable.
Eg that you can stand in front of an X-ray machine for long periods without any danger.
In your view, you may be correct about the machine you have in mind BUT is it true for ANY x-ray machine?
Some may take your statements to be true for any machine.
Just be less general in your statements in these circumstances. Be factual but also give information that leads to safe behaviour, do not encourage actions that may lead to harm.

I would say that for radioactivity, x-ray and microwaves - you cannot see, hear, smell, taste, feel or touch them. They (some but not all)  can penertrate solid matter eg brick. They can do you harm without ANY symptoms.
Knowing this, most are just urging extreme caution. How is someone going to know if they are in danger if there is no indication?
Learn and therefore know what you are doing before attempting some experiment.
It is not just the individual that may be in harms way, in this case it might be someone near by.

I am not arguing with anyone, just trying to help 

[Neukyhm]

you cannot see, hear, smell, taste, feel or touch them.

That's why the first thing I did after decide to build a x-ray machine was buying a Geiger counter 

OP user should already have one. If not, just go buy one, they are not expensive, except those that are expensive.

[Distelzombie]

This post is for everyone to reflect upon. Not just for ebastler.
And I am frustrated and disappointed again, so it sounds a little heated.

EDIT: If this is not the case then tell me. I really want to understand why you would do this constantly, guys. It's the only explanation I have.

I can only speak for myself here. My rationale is pretty simple:

Yes, I believe that it is possible to conduct experiments with X-ray safely, even in a home lab. And they may be interesting and rewaring. But that requires learning, planning, analytical thought, design, risk assessment, ... 

But here we have a person who appears unwilling and/or unable to invest any of these. He instead asks naive questions on an electronics forum, without giving the slightest hint of pre-work, or of following up (by further reading) on various technical suggestions that were given in this thread. Instead, just more "show me" and "tell me".

This is scary. I don't see how the OP expects to build a safe system, unless he had someone physically by his side watching his every step -- because he shows no inclination at all to study beyond the "now show me my next step" level. I feel compelled to tell the OP, and others who may read this thread now or later, that this is not the way to approach such a topic. (And yes, the same holds true for high voltage, high pressure, explosives, ... experiments, in my book).

I was wondering what you are talking about and went to read again what ali_asadzadeh wrote. I wonder how I missed that he has also no clue about how radiation works:
"does x-ray act like a spot light?"

Then yes, it is advised that you read, thoroughly and at least for a few weeks, the theory and proper safety measures before you consider to move onward with this project, ali_asadzadeh! No, really.
I DID say it's ok as long as you don't do it stupidly - but this sounds like it moves into the stupid direction. Let's hope it's not a train.
On the other hand, in favor of your intend: If you're capable of handling high voltage you're basically also able to handle radiation stuff. And you don't really need to know about valence electrons to handle high voltage safely. Surely: Who here knows really what and how an electron is, on the quantum level?
Just read about radiation safety. But do this thoroughly. It's too complex to handle it here. And always question yourself/your next move and what you've build: "Is it really what I think it is?", "Does it what it is supposed to do?" and "Is this my next move ending in the desired result?" are questions that you should write on the back of your hand.

You should also read about philosophy, psychology and neuroscience while you're at it. Just to make sure that you are not doing something you have no clue over how few you really know about it! (Is this a comprehensible English sentence? I don't even know anymore...)

Firstly, let me say that I am trying to be neutral and constructive about the issue.

Yes, some have made flippant remarks but I do not think they have been obnoxious.

Distelzombie, you have made some statements that are questionable.
Eg that you can stand in front of an X-ray machine for long periods without any danger.

That's not what I said. I was talking about dying from it directly.

In your view, you may be correct about the machine you have in mind BUT is it true for ANY x-ray machine?
Some may take your statements to be true for any machine.
Just be less general in your statements in these circumstances. Be factual but also give information that leads to safe behaviour, do not encourage actions that may lead to harm.

I give you that. I think I was overstating it because BFX made an equally overstating argument, that it kills you as fast as high voltage. I probably wasn't even thinking about it in that moment because I was stunned by his statement.

I would say that for radioactivity, x-ray and microwaves - you cannot see, hear, smell, taste, feel or touch them. They (some but not all)  can penertrate solid matter eg brick. They can do you harm without ANY symptoms.
Knowing this, most are just urging extreme caution. How is someone going to know if they are in danger if there is no indication?
Learn and therefore know what you are doing before attempting some experiment.
It is not just the individual that may be in harms way, in this case it might be someone near by.

I am not arguing with anyone, just trying to help 

Radioactivity has the very interesting feature that it is invisible and dangerous, yes, but it's also easily made visible/measureable with a Geiger Müller Counter. Maybe easier than microwaves, but they just heat you up, don't they? (Genuine question. They're not ionizing.)

[helius]

It seems like you're getting forceful disagreement because your tone is argumentative but not necessarily completely accurate.
For example, you referred to "radioactivity" in the context of x-ray experiments, but there is no connection. Radioactivity is the property of unstable atomic nuclei, whether natural or induced. It can only be induced by processes that disrupt the nucleus: mainly neutron activation, but energetic alpha particles and very high energy gamma rays (in excess of 10 MeV) can induce it via photodisintegration. X-rays cannot.

[TurboTom]

@ali_asadzadeh

Yes I reverse engineered the Gendex X-Ray Head, especially since I received it with the tube missing and at that time I didn't know its origin and that a service manual for the Orthoralix 9200 is available publicly: https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiUm62q_-faAhUKGZoKHSp1Dw8QFggnMAA&url=http%3A%2F%2Fwww.kavo.se%2Ffunctions%2Fcsdownload3.aspx%3Fid%3D16175%26org%3D003%26key%3D9e1730570499c6fd3a70835c51d6b852b75b1e573d34416cc3cb90859a3ab0d7&usg=AOvVaw0fzsJIzoNKcoqfLmWH7TRt

Towards the end of the document, there are some block schematics that explain a lot about the working principles. Disregard all the stuff covering the actuators and detector control and it should be possible to control the head with some DIY circuitry.

The capacitors in the cascade are rated 15kV (1nF) and 6kV (33pF). Both transformers (filament and anode) run at 25kHz and have a symmetric drive (two switches for each transformer driven by a symmetric square wave with some dead time between the conduction phases). Some snubber network will probably have to be added. The central tap of the primary coil is supplied by a step-down converter that is part of the EHT feedback loop. The filament converter is part of the tube current feedback loop. The latter has to be equipped with some limiting circuitry, otherwise the filament of the X-ray tube will easily get burnt out. Also some sequencing has to be going on, which is probably managed by the microcontroller shown in the block schematics.

Almost forgot to mention since I consider it to be common knowledge: All these X-Ray heads are placed in sealed enclosures and completely "drowned" in insulation oil (Shell Diala S4 or similar). Otherwise neither the transformers nor the other circuitry would stand the high potential of up to 50kV to ground.

It will be quite a job to get the control scheme for that x-ray head right but it's definitely possible. I won't go into any more detail due to the concerns of some contributors (and partially mine as well). If you really intend to set up a working X-ray system, you should acquire the knowledge necessary to safely handle the extreme voltages, the radiation danger and figure out how to properly operate and drive such a high frequency head. Like other members have pointed out before, there are other approaches that may actually suit your needs better. A typical, complete intra-oral dental X-Ray source sells on eBay now and then for as little as 100...300USD. Brand new, hand-held and battery-operated units are available in China for round about 700USD. All these units usually aren't as flexible as a high-frequency head but I'ld also consider them way less dangerous due to the much lower average output power.

Most important, always play it safe!

Cheers,
Thomas

[MosherIV]

microwaves, but they just heat you up, don't they? (Genuine question. They're not ionizing.)

Unknown for now. There have been a number of studies on the effects of microwave radiation on human body or cells but they all conculded - could not measure any effects.
(Many paid for by mobile phone companies so conspiracy thoery abound).

It is strange that there is a high correlation between rf engineers and rf engineers dying of cancer 

[helius]

Microwaves are considered non-ionizing radiation because the photons themselves are too low in energy to eject valence electrons from atoms. But it is actually quite easy to use microwaves to strike an electric arc, which is an ionized plasma. You can do it with only a grape, or any other poor or good conductor.

[Distelzombie]

It seems like you're getting forceful disagreement because your tone is argumentative but not necessarily completely accurate.
For example, you referred to "radioactivity" in the context of x-ray experiments, but there is no connection. Radioactivity is the property of unstable atomic nuclei, whether natural or induced. It can only be induced by processes that disrupt the nucleus: mainly neutron activation, but energetic alpha particles and very high energy gamma rays (in excess of 10 MeV) can induce it via photodisintegration. X-rays cannot.

Sure there is one connection: X-rays are also created by unstable atomic nuclei. In two ways actually: One is direct decay by x-Ray radiation and the other is Bremsstrahlung through other forms of decay. Also gamma- and x-ray spectra overlap.
These isotopes for example decay by x-ray radiation: Sb117, Sb118, and Sb119
So you can do x-ray experiments in the context of isotope decay. Just think about how radioactivity was found in the first place: By placing a piece of uranium ore on photographic paper in a drawer.

If I remember correctly the process of artificial creation of x-rays is also just high energy electrons crashing into plates- resulting in bremsstrahlung, isn't it?

I also sometimes really struggle to find the right words. I did put emphasize on this by including the German flag in my avatar.
That is the other reason I used that word.
Which word should I have used instead?

[Distelzombie]

I was checking my facts and found that it's also called "electron capture". But I'm sure I've seen it in a different context before. I'll keep searching for that.
https://en.wikipedia.org/wiki/Electron_capture
https://journals.aps.org/pr/abstract/10.1103/PhysRev.72.1070
(I hate that every paper is behind a paywall.)

And apparently there is no real consensus about the differences of x-rays and gamma-rays, so there can also be no consensus about x-rays not being part of radioactivity. Can you not just stop calling it x-rays, america? xD

[amyk]

I also sometimes really struggle to find the right words. I did put emphasize on this by including the German flag in my avatar.
That is the other reason I used that word.
Which word should I have used instead?

Bremsstrahlung is understood in English too.

[Distelzombie]

I also sometimes really struggle to find the right words. I did put emphasize on this by including the German flag in my avatar.
That is the other reason I used that word.
Which word should I have used instead?

Bremsstrahlung is understood in English too.

Why... what? No: I meant instead of "radioactivity" in context with x-ray producing machinery - and the answer is "ionizing radiation".
I know that you know Bremsstrahlung too.

[djnz]

A thing that people seem to have forgotten to stress on seems to be that for evaluating safety, it's not just the instantaneous exposure that matters, but the total accumulation over a period of time. Apart from a Geiger counter, a personal dosimeter is something I'd consider as essential. Also a medical use lead-lined apron is a good idea.

Also, exposing a live being to x-rays just for amusement is not a good idea at all - it has been done by physicists, we know the results and there is very little to be gained apart from amusement from the exercise. To put things in perspective, I have seen surgeons / doctors actively avoid the frequent use of a C-Arm (x-ray imager)  during orthopedic surgery unless absolutely needed, just because it puts the patient at risk. If they are so careful with well maintained commercial x-ray equipment, I think hobbyists have no business exposing living things to x-rays willy-nilly.

[LaserSteve]

This is folly...

Current international work suggests your chance of cancer is increased at 5.5 % per Sv* of adsorbed dose.   Without properly  designed shaped filtering of the beam (Aluminum, Nylon, Moly, Tungsten in sheets and carefully shaped blocks) you might  as well add 2-3% more to that number. Without the filtering your tissue will adsorb large amounts of soft X-rays that are generated by the tube but not powerful enough to expose the film in any meaningful way.

*The 2007 Recommendations of the International Commission on Radiological Protection

http://www.icrp.org/publication.asp?id=ICRP%20Publication%20103

If I would have done what you propose at my former employer, a medical equipment plant that made CT and Mammography gear, I would have been instantly fired. Escorted off the property in minutes, not even a stop at the HR office.   Then Blacklisted from the industry and possibly handed over to a prosecutor.  Walking to the cafeteria without your dosimeter would have got you ONE warning, and the next time would have serious repercussions.


If you don't know what your doing, especially in regards to scatter, adsorption, etc. You'll be overexposed soon enough.  No one here has mentioned one thing we were VERY aware of at the plant, scatter off the ceiling.  Lessons had to be learned the hard way that just shielded walls and windows were not enough.   So even your operating location takes a great deal of planning, expense, and care.

Most people have this vision or model in their heads that a nice cone of X-rays comes out of the tube, terminates at some point,  and that's it.
When you see the diffraction patterns caused by a CT beam hitting metal In the test phantom, you quickly change your mind about what your dealing with.  The OP may never get to see a plot of the raw data from 512 detectors rotating thru 4096 steps per revolution. I have, and I assure you that you will always have some strays going where you do not think there is any radiation.  The ONLY way to be safe is to MEASURE everything.

I made up a special phosphor screen, and used it to demo the shaping and motion of the beam. Some folks had worked there for 20 years and never saw their beam pattern in a direct way.  Moral of the story, you CANNOT assume anything with X-rays!


Steve

[Distelzombie]

If I would have done what you propose at my former employer, a medical equipment plant that made CT and Mammography gear, I would have been instantly fired. Escorted off the property in minutes, not even a stop at the HR office.   Then Blacklisted from the industry and possibly handed over to a prosecutor.  Walking to the cafeteria without your dosimeter would have got you ONE warning, and the next time would have serious repercussions.

I'm not saying that's garbage! But a significant amount of that is just your employer protecting themselves from you: Because if you get sick from radiation you'll probably sue them. Why else would you need a dosimeter in the cafeteria? Come on.

[TurboTom]

Maybe because the cafeteria was located in the second floor of the wooden buiding with the test site in the first floor (in order to reduce back-scatter from the ceiling...) 

Sorry, just had to post this...

[LaserSteve]

Simply for the FDA required  "Good Practices"  discipline of wearing the dosimeter.  Which got sent out for analysis every thirty days.
That and the fact that there were other types of sources in the building.
Plus it is  state law and standard practice in Healthcare..
Hypothetically  a staff member could bypass an interlock cable, leave a lab cell door open, and turn the key, as well.


Really it was just in case Homer Simpson tossed a plutonium paperweight  down the back of my shirt at lunch by accident. See The Simpsons opening title and The Simpsons episode on plant inspection by the NRC. (Attempted Humor there..)





In all seriousness, X-rays are not a good thing to screw around with even as a gifted amateur. Especially in a family home.

Steve

[james_s]

It's like wearing your safety glasses in shop class. If you always have them on, you're never going to forget to put them on before you do something that needs them.

[ali_asadzadeh]

That's why the first thing I did after decide to build a x-ray machine was buying a Geiger counter 

Thanks, It's in my to do list to buy one before, trying anything.

I was wondering what you are talking about and went to read again what ali_asadzadeh wrote. I wonder how I missed that he has also no clue about how radiation works:
"does x-ray act like a spot light?"

  you are right I have no clue right now, and I would not do anything unless I have enough info on the subject, specially when I know and others warn me a lot.

Then yes, it is advised that you read, thoroughly and at least for a few weeks, the theory and proper safety measures before you consider to move onward with this project, ali_asadzadeh! No, really.
I DID say it's ok as long as you don't do it stupidly - but this sounds like it moves into the stupid direction. Let's hope it's not a train.
On the other hand, in favor of your intend: If you're capable of handling high voltage you're basically also able to handle radiation stuff. And you don't really need to know about valence electrons to handle high voltage safely. Surely: Who here knows really what and how an electron is, on the quantum level?
Just read about radiation safety. But do this thoroughly. It's too complex to handle it here. And always question yourself/your next move and what you've build: "Is it really what I think it is?", "Does it what it is supposed to do?" and "Is this my next move ending in the desired result?" are questions that you should write on the back of your hand.

Thanks, I would not even touch anything or buy anything before I got enough info on the subject, because It would be dangerous and also beside being dangerous it would may be ruin my budget

@ali_asadzadeh

Yes I reverse engineered the Gendex X-Ray Head, especially since I received it with the tube missing and at that time I didn't know its origin and that a service manual for the Orthoralix 9200 is available publicly: https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwiUm62q_-faAhUKGZoKHSp1Dw8QFggnMAA&url=http%3A%2F%2Fwww.kavo.se%2Ffunctions%2Fcsdownload3.aspx%3Fid%3D16175%26org%3D003%26key%3D9e1730570499c6fd3a70835c51d6b852b75b1e573d34416cc3cb90859a3ab0d7&usg=AOvVaw0fzsJIzoNKcoqfLmWH7TRt

Towards the end of the document, there are some block schematics that explain a lot about the working principles. Disregard all the stuff covering the actuators and detector control and it should be possible to control the head with some DIY circuitry.

The capacitors in the cascade are rated 15kV (1nF) and 6kV (33pF). Both transformers (filament and anode) run at 25kHz and have a symmetric drive (two switches for each transformer driven by a symmetric square wave with some dead time between the conduction phases). Some snubber network will probably have to be added. The central tap of the primary coil is supplied by a step-down converter that is part of the EHT feedback loop. The filament converter is part of the tube current feedback loop. The latter has to be equipped with some limiting circuitry, otherwise the filament of the X-ray tube will easily get burnt out. Also some sequencing has to be going on, which is probably managed by the microcontroller shown in the block schematics.

Almost forgot to mention since I consider it to be common knowledge: All these X-Ray heads are placed in sealed enclosures and completely "drowned" in insulation oil (Shell Diala S4 or similar). Otherwise neither the transformers nor the other circuitry would stand the high potential of up to 50kV to ground.

It will be quite a job to get the control scheme for that x-ray head right but it's definitely possible. I won't go into any more detail due to the concerns of some contributors (and partially mine as well). If you really intend to set up a working X-ray system, you should acquire the knowledge necessary to safely handle the extreme voltages, the radiation danger and figure out how to properly operate and drive such a high frequency head. Like other members have pointed out before, there are other approaches that may actually suit your needs better. A typical, complete intra-oral dental X-Ray source sells on eBay now and then for as little as 100...300USD. Brand new, hand-held and battery-operated units are available in China for round about 700USD. All these units usually aren't as flexible as a high-frequency head but I'ld also consider them way less dangerous due to the much lower average output power.

Thanks for sharing this info with us, it meant a lot.


Guys thank you all for your contribution and helping me to understand all the concerns about the subject, I will not do anything unless I got enough info and knows a lot about the safty issues,


I have this setup in my mind, I have a basement under the ground floor, it's about 3 meters in the ground, and in the ground floor it's used for my car, it's a parking and on top of that I would have my office, I planed to build a aluminum box and shield inside it with lead, then put the assembly inside it and control all the things from my office, I think this way it would be my safest option, Also I have found these digital sensors,

https://www.hamamatsu.com/us/en/product/category/3100/4011/4157/index.html

 But I think they are way more than my budget, But I wonder how they are built? do you have any clue?

[David Chamberlain]

If you continue down this path then this can be the end result. LOOK This poor chap turned into a dog due to xray radiation sickness. Do you want a tail? I think not.

[ali_asadzadeh]

Code: [Select]

int Days=0;
for( ; ; )
{
    printf("Study X-ray until you get it fully\r\n");
    Days++;
    if(you_could_play_safly_with_xray())
    {
        break;
    }
}

//Now get your hands dirty
printf("It took's about %d days till you get it",Days);


[David Chamberlain]

Ali, I corrected a logical error in your code below by implementing your function and added my own.

Code: [Select]

#define PIGSCANFLY 0

int you_could_play_safly_with_xray() {
    return PIGSCANFLY;
}

// This function allows you to become distracted by all of the
// vastly more interesting topics in physics/electronics.
void bedistracted() {
    // TODO: Complete by OP.
}

int Days=0;
for( ; ; )
{
    printf("Study X-ray until you get it fully\r\n");
    Days++;
    if(you_could_play_safly_with_xray())
    {
        break;
    }
    bedistracted();
}

//Now get your hands dirty
printf("It took's about %d days till you get it",Days);


[ali_asadzadeh]

 
Thanks, any idea about how they build the commercial sensors? like the link that I have sent?

[TopLoser]

https://m.ebay.com/itm/Hamamatsu-CMOS-Image-Sensor-Module-X-ray-Detector-/222330393158

1 image per second by the way

[LaserSteve]

Professional X-ray sensors are often scintillators backed by a silicon detector, either a ccd, avalanche  photodiode or photodiode. In some cases the sensor has an image intensifier in front of it. In a few older machines the sensor will be a Photomultipler tube looking at a scintillator.  For a multi-channel detector close together there usually will be a molybdenum or tungsten cage, mask or or screen between adjacent detectors to prevent cross talk from diffraction or re-radiation from metals.  In many cases this metal shield is designed to function as a collimator.


    In the case of a non-dental medical instrument (CT machine for example)  the sensor is usually a silicon photodiode looking at a scintillator. The output of the diode is ran directly into a current to frequency converter, to get around ADC chip  noise and linearity limits at the low end of the range.  It is far easier to make a good custom, current to frequency converter then to make a good 24 bit ADC chip.

There are direct X-ray semiconductor sensors, they are rare, but they will gain ground in the future. Lithium drift semiconductor detectors have the downside of needing to be cold to work, often at liquid nitrogen temperatures or cooled by a Peltier stack.  These get used mainly in analytical instruments to measure the x-ray spectrum, not it's intensity.

A discrete silicon diode in a light tight package will sense x-rays over a limited intensity range, so will large gate silicon fets  or solar cells to a certain extent.  Just they will have very poor characteristics and sensitivity.



 

Steve

[pcolombo]

I am a retired medical X-ray engineer who ran a business for 30 odd years.  As a result I have collected a large number of X-ray tubes, generators ( high power 1000mA at 140KV), huge numbers of film cassettes, mammography equipment, dental, etc. etc. ad infinitum.  As far as designing, altering, servicing, holding or selling x-ray equipment, one has to be government licensed.  This is the case in Australia.

As far as detecting radiation, the simplest way is to use the white screen inside a film cassette.  These are rated in speed, just like the old camera films.  A slow speed green screen ( the screen will glow green)  of 100 ASA would show little radiation from a tube at low KV and a reasonable glow at a higher KV,  depending on the exposure time.  If one uses a blue screen at 800 ASA then the screen would light up like a Xmas tree, being much more sensitive to X-rays.  Alternatively an interesting tool by Aware electronics    www.aw-el.com/  , will measure  not only X-ray output, but also cosmic radiation,  All 3 types in fact, Alpha, Beta and Gamma.
Whatever you do, unless you don't know what you are doing, to produce X-rays isn't too difficult.  Get a timer ( in milliseconds)  that can switch the primary of a variable transformer with a high secondary voltage ( in a tank of oil), and attach a proper x-ray tube. You will need special cables and plugs for that!   When you "expose"  (the terminology of producing X-rays), all the lights in your suburb will dim for the time of the "exposure" or worse still you will  blow your house fuses.
I would leave this project alone, or join an X-ray company to get some experience if you get my drift.

[ali_asadzadeh]

Dear pcolombo,Thanks for sharing,
In the recent years we have seen many wonderful devices to come a long, features keep going up and prices goes down, I wonder if you know some device manufacturer to cell low cost X-RAY Image sensors, using normal CMOS Image sensors with a film cassette, sound to me somehow old days doing of things, or poor's man job

[james_s]

"Low cost" and "xray image sensors" do not often appear in the same sentence. A friend of mine is a vet tech and the relatively low cost sensor they use is made using a camera array below a phosphor screen and at the time it was around $20k.

[confal44]

Hello,

Dental X Ray machine 60KV or 70KV.

Which tension to choose for a  gendex size 2

Electronic board inspection?(BGA component)

Tks

[MarkS]

I'm going to toss my two bits into this... If you have to ask how to do something on a forum that involves the potential for long term medical issues and death, not to mention possible legal repercussions, you should probably find another project.

[confal44]

Hello

My dentist is the same since 32 years

[Wolfram]

Your dentist also has a shielded room and safety training, make sure you have the same if you want to play with dental X-ray equipment.

The energy depends more on what you want to take a picture of, not so much the sensor. At least as long as the energy is within the range supported by the sensor.

60 kVp gives better contrast with a given subject, and 70 kVp gives better penetration, but the difference will not be very dramatic.

[DavidKo]

Not true anymore. There are small portable x-rays which can be used without shielding. This had came with CCD sensors cca 15 years ago.

[confal44]

Hello,

If I asked this question, it is because I read these two values ​​on the specifications of two portables x-ray devices.
The objective is to X-ray hard material (inspection) and not soft organic material.
Obviously, the device will be isolated in a room covered with lead plates, and the activation will be done remotely.
Finally thank you for the information about the voltage in KV.