Question

Calculate the radiation dosage (in grays) for a 63‑kg person who is exposed for 5.0 s to a 3.0 Ci source of beta radiation. Assume that 100% of the radiation is absorbed and that each beta particle has an energy of 1.5×10−13 J.

Answer 1

Answer:

1.32142x10^-3 Gy

Explanation:

Mass m = 63kg

Time t = 5.0s

Beta energy = 1.5x19^-13J

1 Ci = 3.7x10¹⁰

3.0Ci = 3x3.7x10¹⁰

= 11.1x10¹⁰decay/s

We have a total of 11.1x10¹⁰ beta particles produced per second

The question says there is 100% absorption

Et = (11.1x10¹⁰)x5x1.5x10^-13

= 0.08325

The radiation dose = Et/m

= 0.08325/63 kg

= 0.001321428J/kg

= 0.001321428 grays

Or 1.32142x10^-3 Gy