Re: Fluoroscope (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 18 Oct 2004 23:19:12 -0400
From: Jack Vandam <snotoir7674g@xxxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>, hvlist <hvlist@xxxxxxxxxxxxxxxxx>
Subject: Re: Fluoroscope (fwd)

By placing the tube under oil, you'll have a lot more freedom with the lead
shielding because you won't need to be concerned with arcing and other
issues.  That's what I'm counting on also, but my enclosure is going to be a
bit larger to accommodate experimental tubes and small Tesla coils.

When I worked in the nuclear industry, I did see the SRD's you mention
using- wonder where one could purchase one used at reasonable cost?  That
would be a good device to keep handy for measuring total dose.

Well, I guess your readings basically confirm the one second (or fraction
thereof) chest x-ray dose that exposes one to about the same radiation as
normally obtained from the background over a year's time.   It really
wouldn't take very much time to expose oneself to some really high doses!

Jack

----- Original Message -----
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: "hvlist" <hvlist@xxxxxxxxxxxxxxxxx>
Sent: Monday, October 18, 2004 10:03 PM
Subject: Re: Fluoroscope (fwd)


> Original poster: <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
> >>
> >>
> >>
> >
> >
>
>