[ RadSafe ] Re: "x-ray machines"/radiation therapy devices/photons/electrons & potential isotope proiduction

[stewart farber]

Hi Rainer,
As inferred from the link posted previously:

http://www.yerphi.am/techpd1.pdf

medical radiation therapy electron accelerators of the right energy,  can 
lead to gamma rays in various specifc targets, which might be used for 
isotope production. Interesting possibility that might not have been 
commonly recognized,

Stewart

===========

----- Original Message ----- 
From: <Rainer.Facius at dlr.de>
To: <radproject at sbcglobal.net>; <BLHamrick at aol.com>; 
<sandyfl at earthlink.net>; <radsafe at radlab.nl>
Sent: Wednesday, October 11, 2006 12:27 PM
Subject: AW: [ RadSafe ] NRC Says Indian Point,Other Radioactive Leaks Led 
to Mistrust


Stewart,

thank you for refreshing my memory. Since 1968 I had no reason to think 
about the photo-nuclear effect and the giant resonance cross sections, so I 
forgot. In addition I did not read your previous note carefully enough to 
realize that you were talking about photons and not electrons. :-(


Thanks for your reminder, Rainer



________________________________

Von: stewart farber [mailto:radproject at sbcglobal.net]
Gesendet: Mi 11.10.2006 04:52
An: BLHamrick at aol.com; sandyfl at earthlink.net; radsafe at radlab.nl; Facius, 
Rainer
Betreff: Re: [ RadSafe ] NRC Says Indian Point,Other Radioactive Leaks Led 
to Mistrust


Hi Rainer & all:

For a brief link to an abbreviated discusssion of how high-current electron
accelerators [as with medical radiation therapy linacs potentially which
have electron capability] can produce intense neutron beams from heavy
targets, and near pure isotope production depending on a target see:

http://www.yerphi.am/techpd1.pdf

Electron accelerators have the potential to be used so as to produce large
quantities of Tc-99, I-123, I-128 and other isotopes.

As noted in the  link above:
"The probability of such reactions is characterized by a rapid increase
beyond the energy threshold of nucleon production [mostly lower than 10 Mev)
and an explicit maximum in the  photon resonance absorption range of ~15 MeV
[so called giant resonance]."

Stewart Farber, MS Public Health
The Prometheus Group, LLC
Medical Linac Brokerage Services
[203] 367-0791 [office]
email: radproject at sbcglobal.net

==============================
----- Original Message -----
From: <Rainer.Facius at dlr.de>
To: <radproject at sbcglobal.net>; <radsafe at radlab.nl>;
<sandyfl at earthlink.net>; <BLHamrick at aol.com>
Sent: Monday, October 09, 2006 5:53 AM
Subject: AW: [ RadSafe ] NRC Says Indian Point,Other Radioactive Leaks Led
to Mistrust


Stewart,

which nuclear reactions with stable nuclei can be triggered by 20 MeV
electrons creating thereby radioactive, i.e. unstable nuclei?

Rainer

________________________________

Von: radsafe-bounces at radlab.nl im Auftrag von stewart farber
Gesendet: Mo 09.10.2006 05:51
An: radsafe at radlab.nl; sandyfl at earthlink.net; BLHamrick at aol.com
Betreff: Re: [ RadSafe ] NRC Says Indian Point,Other Radioactive Leaks Led
to Mistrust



Hi all,
Before dismissing the quote out of hand, bear in mind we really don't know
for sure what is being referrred to.

If by "x-ray equipment" the article is making reference to a linear
accelerator [linac] used in radiation oncology [and not just a simple x-ray
unit used for diagnostic purposes], these linac units can put out a steady
beam of photons in multiple energies of from 6MV to 18MV or more [as well as
electrons in multiple energies up to 20 MeV or more]. Linacs can be used to
irradiate target materials which can make radioactive isotopes which could
theoretically be used for illicit purposes.  Just a thought which should be
recognized.

Hospitals and therapy centers often upgrade their installed linacs and the
older units are deinstalled and sold in the US and abroad.

Stewart Farber, MS Public Health
The Prometheus Group, LLC
[203] 367-0791 [office]
email: radproject at sbcglobal.net

----- Original Message -----
From: <BLHamrick at aol.com>
To: <sandyfl at earthlink.net>; <radsafe at radlab.nl>
Sent: Sunday, October 08, 2006 9:24 PM
Subject: Re: [ RadSafe ] NRC Says Indian Point,Other Radioactive Leaks Led
to Mistrust


>
> My favorite part of the RDD nonsense written is the excerpt below.
> Ummm...good luck with finding radioactive material in the x-ray equipment.
>
> Barbara
>
> In a message dated 10/8/2006 6:20:38 P.M. Pacific Standard Time,
> sandyfl at earthlink.net writes:
>
> Scientists responsible for analysing the seizures have given warning
> that traffickers are turning to hospital X-ray equipment and
> laboratory supplies as an illicit source of radioactive material.
>
>



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