Question

A 0.15kg tumor is treated with α

α particles. There are 2×10

12

2×1012 particles reaching the tumor every second, each having energy 3×10

−15

3×10−15J. What is the absorbed dose given to the tumor

Answer 1

$m=0.15 \; kg \\ n=2 \times 10^{12} \; particles \\ E = 3 \times 10^{-15} \;J$

The absorbed dose $= \frac{nE}{m}$

$= \frac{2 \times 10^{12} \times 3 \times 10^{-15}}{0.15} \\ = 40 \times 10^{-3} \\ = 0.04 \;J/kg \cdot s$