Photographic plate for X-rays / General Science and Electronics / Forums

Forums

4hv.org :: Forums :: General Science and Electronics

« Previous topic | Next topic »

Photographic plate for X-rays

1 2 3 next

Move Thread

LAN_403

uzzors2k

Fri Nov 17 2006, 06:32PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

I have plans to make an x-ray machine in the distant future, but I'll need some sort of an x-ray cassette to take pictures of objects. Since I'm constantly stretched thin for project money, I want to make a diy x-ray cassette. I remeber one of the board members used glow in the dark strips, would any glow in the dark material work?

Also I have 3 gutted CRTs lying about, ready to go to the dump. Would be possible to remove the phosphorescent screening from the inside of the crts and use it for an x-ray cassette? Is it even possible to remove, and would it even work?

Marko

Fri Nov 17 2006, 08:23PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

TDU wrote ...
The phosphor is scraped from the inside of a colour TV screen delicately smashed to get good access and with a towel over it to prevent implosion and glass fragments. It fluoresces white under a UV light (see the nitrogen laser thread).

Phosphors in color CRT's are tons of various salts

wich usually exibit very short presistence, and you'l have to photogaph everything in realtime with X ray tube on;

If you can find some phosphorescent (glow iin dark) stuff it may be more practical for taking pics, but will need refactory time.

Just don't blow yourself up together with that CRT's. Try blanketing them in some waterproof awning in order to keep fragments and phosphor in.

uzzors2k

Sat Nov 18 2006, 10:53AM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

I'll be careful smashing the CRTs, but its the phosphor that worries me. Are any of the salts toxic? It seems to depend on the website you go to. According to

I should find these salts in the CRT.

Blue (P-22B) ZnS:Ag
Blue (P-22B) ZnS:Ag+Pigment
Green (P-22G) ZnS:Cu,Al
Green (P-22G) ZnS:Cu,Au,Al
Red (P-22R) Y2O2S:Eu
Red (P-22R) Y2O2S:Eu+Pigment

I know I shouldn't inhale them, but would anything happen if I got some on my hands or clothes by accident? I cant find much info about toxicity on google, but it seems the Zn salts are safe at least. Also, will these salts decompose outside of the vacuum?

Marko

Sat Nov 18 2006, 11:18AM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

You have a large list in wikipedia.

Simple Zinc sulfide isn't dangerous in such concentrations, don't know for Y2O2 but you should be safe unless you swallow or inhale very large amounts of it.

Just mix the powder with some epoxy and make yourself a cassete...

uzzors2k

Sat Nov 18 2006, 12:35PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

Great, I'll finish gutting the monitors and then I'll give this a go. Thanks for the help Firkragg.

Avalanche

Sat Nov 18 2006, 01:26PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

Just wondering, would the coating from within a fluorescent tube be any good for this application? It is very easy to remove, on a tube I accidently broke the fluorescent material pretty much brushed off the inside of the glass.

Marko

Sat Nov 18 2006, 02:51PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Don't know. Tried xrayng some of it?

When I put it under UV LED it flourescenced poorly blue, somewhat like paper, but even more poorly.

I guess it needs smaller wavelength of UV to light itself up properly, so it_may_work for xray stuff.

c4r0

Sat Nov 18 2006, 05:07PM

Registered Member #151 Joined: Sun Feb 12 2006, 02:53PM
Location: Poland
Posts: 153

uzzors wrote ...
I remeber one of the board members used glow in the dark strips

Hi, it was me

Here you have some photos taken using this method:

As you can see it works, but the real intensyfing screen is very much better. I have two types of screen now: green (fuji mammo fine) and blue (perlux). It's hard to find, but if you're lucky you can buy two old 35x35cm screens for about 3USD + shipment costs, just like me

Here on the left is some phosphorescent powder from a compact fluorescent lamp. So it glows red under x-rays. But i think you should use something 'glowing in the dark', or at lest try it first.

Here some photos which are not on my site yet (photos taken about two manths ago). 80-90kV @ 2s exposure time. Digital still camera was standing directly behind the screen, with no mirror or other unnoising stuff.

1163867702 151 FT18063 Dsc00729ps G 90kv 2sx

Compare of green and blue screen:

I also tried to make some x-rays without any real x-ray stuff. Here is the result i get with connecting a vacuum diode to my mini sstc:

Preety good results

But i was using an intensyfing screen. Now i'm going to try it with these glowing in the dark strips, then it will be completely selfmade x-ray machine

uzzors2k

Sat Nov 18 2006, 07:23PM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

Thats right, you and Teslacoiler were the X-ray guys.

Pretty awesome stuff.Heres one of the old threads

I think my x-ray setup will be pretty diy, depending on the success you have with the glow-in-the-dark strips.

Where do you get all of that stuff anyway? On the internet, ham- get togethers, people you know? 3USD for an x-ray cassette is amazing!

...

Sat Nov 18 2006, 07:56PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

There is the $121 self-contained, already-working, x-ray source I posted in the sale/trade...

It was $10 at the time, but it has risen up a bit since then

Can't beat free shipping

1 2 3 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob