Re: Fluoroscope (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 18 Oct 2004 14:38:44 -0400
From: humanb@xxxxxxxxxxxxxxxxxxx
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Fluoroscope (fwd)

Yes you are right; x-rays are not to be fooled with. I was 
using a bare tube, but will be working to setup a shielded 
enclosure before I use it again, and also put it under oil 
as the tube can get hot, not to mention corona. I used 
Geiger counters backed up with SRD's (self-reading 
dosimeters) to measure the "low-dose" areas. For the 
extreme high dose rate areas (in the beam shine, and next 
to the tube) I used the SRD's and a stopwatch to get a 
good approximate reading.

I do want to emphasize though, that I would highly advise 
folks not to try this unless you have experience in 
radiation safety and have the correct dosimetry and 
radiation detection equipment. I worked as Health Physics 
Technician from 1988-1996 and have handled sources up to 
400 Curie Cs-137 ones used for calibration, and I will 
tell you I have just as much respect for this x-ray tube 
as I would for one of those! I am thinking that this tube 
when run at 80KV and full filament voltage will be able to 
put out in excess of 500 R/Hr, that’s nearly 140 
mRem/second!

As I mentioned on the Fusor board, I now have renewed 
respect for the regulations regarding the used and 
maintenance of X-Ray equipment.

Be safe,

David Trimmell

[Remember that radiation doesn't just light up the things you point it at.
There's scattered radiation to contend with as well, so a site survey and
proper dosimetry is very important.. SRR]

On Mon, 18 Oct 2004 10:48:33 -0600 (MDT)
  "High Voltage list" <hvlist@xxxxxxxxxx> wrote:
> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 18 Oct 2004 01:47:41 -0400
>From: Jack Vandam <snotoir7674g@xxxxxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Fluoroscope (fwd)
> 
> Nice radiographs!  Taking them with a digicam from the 
>screen as you did is
> very convenient.  An actual x-ray tube, as you have, 
>does put out a
> surprising amount of radiation.  The way you describe 
>your setup, it doesn't
> look like you used an actual "closed" x-ray head.  I'd 
>be more interested in
> hearing about it.  Did you have to oil immerse the tube? 
> Also, how did you
> go about obtaining your radiation measurements?
> 
> X-rays definitely aren't anything to fool around with 
>without protection and
> I am currently fabricating a 2' hollow leaded cube, 
>where the x-ray source
> and object can be totally enclosed before making 
>exposures.
> 
> Nice work!
> 
> Jack
> 
> ----- Original Message -----
>From: "High Voltage list" <hvlist@xxxxxxxxxx>
> To: "hvlist" <hvlist@xxxxxxxxxxxxxxxxx>
> Sent: Monday, October 18, 2004 12:52 AM
> Subject: RE: Fluoroscope (fwd)
> 
> 
>> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>>
>>
>>
>> ---------- Forwarded message ----------
>> Date: Sun, 17 Oct 2004 11:41:54 -0700
>> From: David Trimmell <humanb@xxxxxxxxxxxxxxxxxxx>
>> To: 'High Voltage list' <hvlist@xxxxxxxxxx>
>> Subject: RE: Fluoroscope (fwd)
>>
>>
>> Hi, well I have set everything up and used those screens 
>>I got from
>> Steve Roys all those years ago, and have some pictures. 
>>I found that the
>> X-ray screens take a minimum of 4 R/Hr. to fluoresce, 
>>and become quite
>> visible at over 15 R/Hr. I must say that I was somewhat 
>>surprised at
>> just how much radiation is put out by an x-ray tube. I 
>>was running at
>> around 40KV (half the ratting of the transformer) and 
>>with about 5 Volts
>> on the tube filament, I get over 140 R/Hr. at 6". No toy 
>>here folks.
>>
>> Well here are the radiographs I took:
>>
>> http://www.chaoticuniverse.com/webdoc3.htg/Nuclear_Stuff/X-Ray_stuff/X-r
>> ay_system/10-16-04_Radiographs/
>>
>> Regards,
>>
>> David Trimmell
>>
>> Note: I certainly was not "holding" the camera! 
>>Everything was done
>> remotely. I hope no one tries this without proper 
>>training in radiation
>> protection and correct dosimetry and radiation detection 
>>equipment.
>>
>> ---------- Forwarded message ----------
>> Date: Sat, 9 Oct 2004 15:03:54 -0700
>> From: David Trimmell <humanb@xxxxxxxxxxxxxxxxxxx>
>> To: 'High Voltage list' <hvlist@xxxxxxxxxx>
>> Subject: Fluoroscope
>>
>> Hi all, I will shortly be receiving a nice dental X-Ray 
>>transformer with
>> tube and filament transformer to go with it. This will 
>>be setup as PSU
>> for some vacuum experiments, but will also be used with 
>>the x-ray tube
>> to some x-ray experiments. One such thing I will want to 
>>try is a
>> Fluoroscope. I will, of course, be using proper Health 
>>Physics controls
>> and am aware of the hazards. There will be no exposure 
>>of "live" tissue.
>> But does anyone know of a source for the properly doped 
>>Zink Sulfide
>> phosphors, or strontium aluminate's? Has anyone here 
>>actually made a
>> Fluoroscope? I have no intentions of viewing this 
>>directly, as I will
>> use either a video camera or a reflected image. Believe 
>>me I have no
>> intention of sticking my head in a potentially lethal 
>>x-ray field. Any
>> suggestions would be great.
>>
>> Thanks,
>>
>> David Trimmell
>>
>>
>>
> 
>