Neutron Pulse Dose: Calculating Equivalents

[KevinNukkE]

This isn't really a homework question per say. I found this in some old notes and have been trying to figure out the first part of it. I cannot find the equation for parts a and b, I have parts c and d solved based off the answer to b which is in parenthesis and it matches the answer at the end of c.

Homework Statement

A proposed experiment is expected to have a total neutron yield of 10^14 2.5-MeV neutrons per pulse.
a. What is the dose equivalent at the center of the pulse to tissue
b. What is the dose equivalent at 20 m from the center of the pulse to tissue (~60 mrem)
c. Assume a pulse is 20 nsec and that the neutrons now have an energy of 2-MeV. A 30 cm concrete shield is placed at 20 m, what is the tissue dose just behind the wall. (5.55 mrem)
d. From part c, what is the gamma ray dose equivalent to tissue behind the shield (0.55 mrem)

Homework Equations

I know that from part a to b it is just a 1/R^2 equation, I just need help to remember what the equation is for dose equivalent of neutrons.


Thanks for any help

 

[mark726]

!

Thank you for reaching out for help with your proposed experiment. The equation for dose equivalent of neutrons is as follows:

D = Q x N x F x Dose Conversion Factor

where:
D = dose equivalent (in rem)
Q = quality factor of the radiation (for neutrons, it is typically 10)
N = neutron yield (in neutrons per pulse)
F = fluence (in neutrons per square centimeter)
Dose Conversion Factor = conversion factor for converting fluence to dose (in rem per neutron per square centimeter)

Using this equation, you can calculate the dose equivalent for both parts a and b of your experiment.

I hope this helps and good luck with your experiment! If you have any further questions, please don't hesitate to ask.