Pu-238 (T1/2 = 87.7 years) is to be used as a heat source in a radioisotope thermoelectric generator (RTG) for a spacecraft.
a. Write the decay equation if Pu-238 emits an alpha particle.
b. What is the Q-value of the decay?
c. What is the energy of the recoil nucleus when the alpha is emitted to the ground state of the daughter?
d. What is the specific activity of Pu-238?
e. If the activity of Pu-238 at launch is 1000 Curies, how many nuclei are present at launch?
f. The RTG is to produce 125 W of electrical energy after 10 years in space. If the thermal-to-electrical conversion efficiency is 12.5%, what must the thermal power output be at the time of launch?
g. What mass of Pu-238 is required at time of launch to produce a thermal output of 1500W?