Homemade X-Ray Machine: Liftoff

[technix]

Somehow I feel you should be buying lead-loaded protection gear or put the whole thing in a cellar.

[AutogolazzoJr]

The machine is not in working order right now. I need to get more tubes from my russian seller. When I run the x-ray machine, I am nowhere near it. It's all done remote.

[james_s]

Why do you need more tubes? Did you blow up the one you had? It should only take one tube.

[Wolfram]

As far as I understand, he's (ab)using high voltage rectifier tubes to generate x-rays in cold cathode mode by overvoltage. They usually don't last very long and they don't have a well defined focal spot, making it difficult to take sharp x-rays with them. These tubes are pretty cheap to start with, but they don't last very long, so it usually makes more economic sense to get a dental x-ray tube to start with if you plan on taking more than a couple of x-rays. The only case where it makes sense to do this if you want to make a point out of generating x-rays without a purpose-designed x-ray tube.

[AutogolazzoJr]

I don't really have access to dental x-ray heads. My mission is part proof of concept, but I'd like to get some good images out of it while still staying safe. I have some better pictures:

[Wolfram]

Those are pretty good pictures for such a setup. The broad focal spot gives the images an interesting look, maybe that could even be used to artistic effect, if your intention is making interesting-looking images.

If you at some point want to get a purpose-made x-ray tube, note that x-ray heads can often be had for less than equivalent x-ray tubes on eBay. Another bonus is that they come with a nice power supply included, either an iron core transformer or a high frequency transformer + multiplier setup.

[AutogolazzoJr]

Thanks! As for james_s, the 5 tubes that I used have all either lost vacuum or no longer produce bright images. They don't last very long. A long cool down time should help.

[james_s]

Oh, yeah forget trying to use rectifier tubes to make xrays, why bother? I've bought complete dental xray heads for less than $100 before, you could easily spend that much killing other kinds of tubes and you'll get FAR better performance from the real deal. In addition if you buy a complete head you'll have something that is much more convenient to use and more importantly, much safer.

https://www.ebay.com/itm/Gendex-x-ray-head/113322808953

https://www.ebay.com/itm/Gendex-GX-900-Tube-Head-only-Dental-X-Ray-ge-INTRAORAL/372482456855

https://www.ebay.com/itm/MarksMan-I-SS-White-dental-X-ray-head-medical-xray/223205413866

[AutogolazzoJr]

Here is the imgur: https://imgur.com/gallery/BbXQRhR

[Gyro]

You really used it on human flesh?  That rather implies that the rest of you was in the close vicinity too.

EDIT: Looking back to the OP, I see you are only 15. It might be time to grow up if you want to make it to16 - seriously, take it from those of us who know, cancer is no fun.

[EEVblog]

Here is the imgur: https://imgur.com/gallery/BbXQRhR

Please DO NOT use this xray machine on yourself, this can be SERIOUSLY DANGEROUS to your long term health.

We applaud a 15yo building their own xray machine, but we are deeply concerned for your safety.
The fact that your xrayed your own hand shows how little you are taking safety seriously.

[Gyro]

You see all those bright pixel dots on the images of your hand and foot - and particularly on the closeup photo of the tube, those are strikes by soft x-rays and other particles.

A medical X-ray head has a Aluminium (or other metal) filter to get rid of these, leaving only the hard X-rays. Soft X-Rays from a 'dirty' source are absolutely the worst as they are absorbed by flesh rather than passing straight through. You took quite a high dose of them there.

[InductorbackEMF]

As neat as it is to see please do not try xraying your self again.
Try chicken bones or something else. 
(Oh and i would frame the picture of your hand on a wall)


Alex.

[AutogolazzoJr]

It was a bad idea. However, I later realized how bad of an idea it was, so I stopped doing it. I told you that everything was done remotely. That wasn't (obviously). I used lead protection on the rest of my body, and I believe it was a safe dose (EDIT: it's not. Soft x-rays). As I said, I no longer do it. Thanks to all of you whom are concerned with me. I don't use the x-ray machine anymore, but I might soon. For all the pictures taken after the flesh ones, I completely left the room.

[AutogolazzoJr]

Here is the imgur: https://imgur.com/gallery/BbXQRhR

Please DO NOT use this xray machine on yourself, this can be SERIOUSLY DANGEROUS to your long term health.

We applaud a 15yo building their own xray machine, but we are deeply concerned for your safety.
The fact that your xrayed your own hand shows how little you are taking safety seriously.

I do and did take safety seriously. The exposure lasted one second. I used a Geiger counter to make sure I wasn't receiving too much of a dose. I used lead to shield the rest of the room and my body. More info above, and thank you for concerning my safety.
As a teenager, I lack judgement. I obviously need to be taking this more seriously, which I did after I took those pictures. If I actually revive this project, I will take even more safety measures to make sure nobody gets injured.

[Gyro]

Your response to the safety feedback does you credit, many teenagers wouldn't have been so mature about it. You've obviously had a fright, but have hopefully done yourself no damage. Pausing the project at this stage is probably a good thing - it will give you time to get a pencil and paper out and start thinking about how you can improve the setup, both from the safety perspective and for achieving a better point-source for focus... and protecting your camera too (those pixel speckles were rather impressive!). Maybe a better source will turn up too.

It's probably also a good time to do some research on the history of X-rays, and the early pioneers rather than just current implementation. It's a fascinating reading about the early set ups and the mistakes they made. I remember seeing the images of one early radiographer in a London hospital who actually documented the crumbling of the bones in his hand over many relatively uncontrolled exposures. It's believed now that Marie Curie, after all the risky stuff that she did isolating Radium and Polonium, may well have died, age 66, as a result of the X-ray exposure from the work she did running an X-ray machine in the field during the first world war. As I say, there's a lot of interesting reading to be found on the web.

I'm not sure how your metalworking skills are, but you could maybe look at mounting the tube in an offcut of cast iron or steel pipe with a window cut in it, you could then experiment a bit more easily with plates with different apertures to try to improve focus. You'd probably need the Lead too, but it might help to constrain things a bit better.

There are also members on this forum with professional X-ray experience, Fraser comes immediately to mind but I'm pretty sure there are others.  They may be able to offer you practical and safety advice too. Do some forum thread searches.


I really hope none of the above comes across as condescending, as Dave said, it's seriously impressive that someone of your age can come up with anything of that sort of power, PSU included. I have a Hitachi Kenotron tube, which a few seconds experiment with 25kV (forward direction) and a geiger counter was enough to scare me. At 45 years older than you, I haven't plucked up the courage to take it any further yet, because I don't really trust myself not to cut corners on safety!

[james_s]

Seriously, just use a proper xray head, or don't play with this stuff at all. Taking an xray of one's hand with an un-shielded rectifier tube means a significant dose to the rest of the body, even if you try to protect it it's very hard to protect everything. There tends to be a lot of safety hysteria in the world these days but this is one of those cases where the concern is justified. Xray photons pass through your body, blasting apart your DNA. It's a bit like UV exposure from the sun except it penetrates all the way down through your tissue and bones. As has been mentioned, the soft xrays are particularly dangerous, a real xray head has an aluminum filter to block those.

[Treehouseman]

I'm going to put in another vote for just getting a dental xray head, they're easy to use and they're a good known level to work with. Though I will also note that the entire "the xray head will filter those soft xrays" thing is a bit inaccurate, I still get hot pixels on my camera when using the xray head even if it's not in the path of the beam. Granted I don't know what exactly he's running at and what his camera settings are, but they do still happen. This isn't to say that running that tube without shielding isn't insanely stupid, but a sheet of aluminum doesn't stop those stray xrays.

[BFX]

From the photos what I seen I'm almost sure you have to stop your experiments right now for a long time!!! 
This is not dangerous only for you but also for your family or neighbors.
And I need to mention that you can finished with your "experiments" in the jail!
Again !!! X-Rays are more dangerous than main voltage! Believe me I'm X-Ray medical machine developer.

[AutogolazzoJr]

I haven't x-rayed anything since may. I have no plans to x-ray anything soon. Thanks for the warning, though.

[PointyOintment]

Those pictures of the fan, with the back side much larger than the front side, show that the beam is very wide. At first I thought that made it more dangerous (to bystanders, neighbours, …), but then realized that that means the beam rapidly gets less intense with distance, which is better for safety. I don't know which effect (more or less dangerous) is more important in this case. Regardless of that, I wouldn't run it when it's aimed in any direction but down into the ground, just to be careful.

[james_s]

I'm going to put in another vote for just getting a dental xray head, they're easy to use and they're a good known level to work with. Though I will also note that the entire "the xray head will filter those soft xrays" thing is a bit inaccurate, I still get hot pixels on my camera when using the xray head even if it's not in the path of the beam. Granted I don't know what exactly he's running at and what his camera settings are, but they do still happen. This isn't to say that running that tube without shielding isn't insanely stupid, but a sheet of aluminum doesn't stop those stray xrays.

High energy xray photons can interfere with the camera too. Also perhaps "attenuate" would be a better word than "stop", the aluminum filter blocks the low energy xrays the way glass blocks UV. It doesn't stop 100% of it but it does greatly reduce the amount that gets through. A dental xray head can still be quite dangerous if one is careless, but it's far safer than an open tube.

Whatever the case, where you need to be paranoid is when you have any chance of exposing other people. Few things get people scared to irrational levels like the word "radiation" and if anyone thinks they might have been exposed, even if the level is far too low to cause any harm, you can end up in a lot of trouble.

[mr_darker]

There's a good guide on making xrays and safety too, on instructables actually, probably the only decent instructable on that site.
https://www.instructables.com/id/How-to-X-Ray/

[SiliconWizard]

Hopefully your next project is not involving plutonium.

Seriously though, however interesting that may be, experimenting with X-Rays as an amateur is probably best avoided.

[tggzzz]

Hopefully your next project is not involving plutonium.

Seriously though, however interesting that may be, experimenting with X-Rays as an amateur is probably best avoided.

As my 1930s book "The Boy Electrician" notes, if your skin turns red you are probably using it too much.