Re: Mrad dosimetry

[MCNAUGHT@Lanl.GOV (Mike McNaughton)]

Igor Azhgirey in Moscow asks:
>does anyone know the reliable tool for the megarad dosimetry measurements
>in the mixed high-energy accelerator generated field except ionisation
>chamber?
REPLY: first, please allow me to rephrase the sentence:
>does anyone know a reliable tool, other than an ionization chamber, for 
>megarad (10 Mrad) dosimetry measurements in the mixed field generated by a
>high-energy accelerator?

ANSWER:
I believe that an ionization chamber is the best choice for betas and gammas,
but high-energy neutrons are difficult. I assume your accelerator is pulsed; 
(is it the 600 MeV Moscow linear accelerator?) Nobody in the world knows how
to make reliable measurements of neutron dose above the pion-production
threshold (300 MeV).  There is a device known as the "Albatross", developed
in conjunction with the LAMPF accelerator at Los Alamos, which gives
reasonable measurements of pulsed neutrons up to 800 MeV, but we argue about
how accurate it is.

I would be happy to discuss this in more detail.

Mike McNaughton
MCNAUGHT@LANL.GOV