Re: bremsstrahlung dose rate off off beta emitters

["Tom Johnson" <tjohnson@radtrain.com>]

>>Can anyone recommend a reference (or does anyone have measurements)
>>specifying
>>1. the bremsstrahlung dose rates off beta emitting sources (e.g. P-32,
>>Sr-90) in water or tissue? (And I need an answer more quantitative than
>>"not very much").
>>2. the broad-beam transmission of these bremsstrahlung photons through Pb
>>and concrete?

In Herman Cember's book he has an equation for estimating the bremsstrahlung
in chapter 5, page 130 in the third edition of "Introduction to Health
Physics". The formula for calculating the effective "Z" of the material is
found in Chapter 10. He also states that the "average" energy of the
bremsstrahlung photons is about 0.16 times E max of the betas.  Once the
"average" energy is found, the broad beam transmission can be found using
curves found in chapter 10 of the same book as well. It may not be as easy
as using a computer program but it might be interesting to check and see how
well they compare.

I think it would be very interesting if you would let everyone know how the
results compare. If no one else is interested, at least I am! Give me a call
if you have questions on using this technique.

Tom Johnson
(301)942-5946
tjohnson@radtrain.com