Grenadier's big thread of RÃ¶ntgen related shenanigans / Electromagnetic Radiation / Forums

Forums

4hv.org :: Forums :: Electromagnetic Radiation

« Previous topic | Next topic »

Grenadier's big thread of RÃ¶ntgen related shenanigans

first previous 19 20 21 22 next last

Move Thread

LAN_403

klugesmith

Tue Apr 12 2011, 07:59PM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716

Grenadier wrote ...
It works :D
... And of course I couldn't call it a night without x-raying a few things.

Congratulations, Adam.

I'll get your 200 mR pen dosimeter in the mail by tomorrow. Don't run it offscale on the first shot or two, or you'll be scrambling to get a charger for it. Normal digital-sensor exposures at my dentist's office register around 12 mR or 0.12 mGy.

Rich

Adam Munich

Wed Apr 13 2011, 05:47AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

That makes quite a bit of sense and I tried to reach 75kV today, but I got little done because mother nature rained on my radiation parade. I did notice something though; popping. I set up my camera on a 10sec timer to see what it was and it turns out the kilovoltmeter's resistor was sparking to the lead shield.

How this was possible idunno, but I think it might be because something became a capacitor.

I was going to solve this with hot glue, but then the oil leaked all over and I swore something fierce. I've had it with leaking oil so I dumped it all out and then cleaned the outside of the PP as best I could with alcohol. I then put the lid on and hot glued the hell out of it (hot glue actually sticks to PP like cement).

After that I punched a hole in the lid and used a pipette to squirt some degassed tranformer oil in there, then sealed up the hole with hot glue. So far it hasn't leaked, and if it doesn't leak then it ought to be good for a couple years.

Hopefully I have the beam centered right.

radhoo

Wed Apr 13 2011, 10:07AM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701

I'm starting to think oil created more problems for you than it solved.

Here are two opposite polarities Glassman multipliers working together for close to 140KV discharge (each multiplier is rated for 60KV max, I pushed them a little bit further):

If you look at the pictures you will see, there is no oil, only AIR in these multipliers, and there's no corona, not arcing, they were designed to work in air and they do a decent job.

Maybe this gives you some more ideas.

Adam Munich

Wed Apr 13 2011, 10:41AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Nah I solved the CW leaking, and I think I solved the tube leaking too now. The tube can't be run in air because it's so small (it'd flash right over in air), and the oil also convects away the anode heat..

Adam Munich

Wed Apr 20 2011, 03:17AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Back to square one, minus $50. There is sparking inside the lead sheild and I have no way to solve it but to start over, this time putting everything under oil. Since I don't have enough lead sheet to make a new box I'm just going to make a very thick tube jacket, then put one layer of lead around the container and hope for the best. Of course I need to find a suitable oil-tight container now because I've freaking had it with oil leaking everywhere. I have not one pair of pants that hasn't been stained with oil...

I'm really losing my motivation,

Xray

Wed Apr 20 2011, 05:11AM

Registered Member #3429 Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288

Grenadier wrote ...

I have not one pair of pants that hasn't been stained with oil...

Welcome to the world of X-ray equipment!

I wish I knew you (or rather, you wish you knew me) back in June of last year when I moved from Wisconsin to Minnesota. I got rid of a large box of lead shielding material (about 50 pounds of it!). Anyhow, there is some lead sheets in those heads I sent you. There should be enough to make another small box.

James

Wed Apr 20 2011, 05:39PM

Registered Member #3610 Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506

Or maybe use one of the heads as a box? An x-ray head seems like the obvious thing to enclose a tube in :)

Adam Munich

Thu Apr 21 2011, 01:00AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Using a head would be too easy! How could I say that I made anything if I just used a head?

Anyway... here is my "x-box"

Basically I put everything inside a PVC junction box, and it turned out awesome. I can't test it because I forgot to get a plug for that hole, and it's 37* and raining out. F*cking buffalo...

Nonetheless I used 6mm of lead for the tube jacket so very little external shielding should be needed. Funny how once you've spent months doing everything wrong, it takes only 5 hours to do it right.

James

Thu Apr 21 2011, 01:58AM

Registered Member #3610 Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506

Well you didn't make the tube or the capacitor anyway, and there's that whole saying of no need to reinvent the wheel. That PVC junction box does look like a nice clean housing though.

magnet18

Thu Apr 21 2011, 01:59AM

Registered Member #3766 Joined: Sun Mar 20 2011, 05:39AM
Location:

Posts: 624

Grenadier wrote ...
Funny how once you've spent months doing everything wrong, it takes only 5 hours to do it right.

Experience, It's a wonderful thing.
Just gotta hang in there long enough to get it right.

first previous 19 20 21 22 next last

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