X-ray generation and detection

[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.