How Do You Calculate Radiation Dose and Beam Current from Proton Exposure?

[xamy]

Homework Statement

A worker inadvertently puts his hand at right angles into a uniform, parallel beam of 50-MeV protons with a fluence rate of 4.6×1010 protons cm–2 s–1. His hand was momentarily exposed for an estimated 0.5 s.

(a) Estimate the dose that the worker received to the skin of his hand.

(b) If the beam covered an area of 2.7 cm2, what was the beam current?

Homework Equations

D=energy fluence rate(mass energy-absorption coefficient)

The Attempt at a Solution

energy fluence rate=4.6×1010x0.5x500M
I don't have mass energy-absorption coefficient.

I don't think I am using the correct formula. I am clueless right now. I have tried a lot but couldn't find anything else. Need help

 

[mfb]

The Bethe formula should give a good approximation.