Question
a. how many grams of ~~
b. Sr-90 is to be used as a heat source~~
c. Weight of the isotopic heat source~~
3. (a) How many grams of Y are there when y is equilibrated with 10 mg of "Sr? (b) Sr-90 is to be used as a heat source for generating electrical energy in a satellite. How much of Sr-90 activity is required to generate 50 W of electric power if the conversion efficiency from heat to electricity is 30%? (c) Weight of the isotopic heat source is an important factor in design of the power source. If e eightof th lopic heat source is an important factorin design of the power source. If weight is to be kept at a minimum and if the source is to generat would there be an advantage to using 21"Po? is to be kept at a minimum and if the source is to generate 50 W after 1 yer operation
Explanation / Answer
a) grams of 90Y = 10 * 10-3 * 90 = 0.9 gm
b) Sr-90 activity required = (50 * 0.30)/0.9
= 16.67 Ci/gm
c) No, there would be no advantage to using 210Po .