Samarium-151

Medium-lived fission products
t^½(y)		Yield%	KeV	β
¹⁵⁵Eu	4.76	.0330	252	γ
⁸⁵Kr	10.76	.2717	687	γ
^113mCd	14.1	.0003	316
⁹⁰Sr	28.9	5.7518	2826	β
¹³⁷Cs	30.23	6.0899	1176	γ
^121mSn	43.9	.00003	390	γ
¹⁵¹Sm	90	.4203	77

Long-lived fission products
t^½(my)		Yield%	KeV	β
⁹⁹Tc	.211	6.0507	294
¹²⁶Sn	.230	.0236	4050	γ
⁷⁹Se	.295	.0508	151
⁹³Zr	1.53	6.2956	91	γ
¹³⁵Cs	2.3	6.3333	269
¹⁰⁷Pd	6.5	.1629	33
¹²⁹I	15.7	.6576	194	γ

¹⁵¹Sm is an beta emission, and a fission product yield of 0.4203%, about 39% of Sm-149's yield.

Its neutron absorption cross section is high at 15200 Barn (unit)s, about 38% of samarium-149's absorption cross section. Since the percentages are almost equal, the two isotopes should reach similar equilibrium concentrations. Since ¹⁴⁹Sm reaches equilibrium in about 500 hours (20 days), ¹⁵¹Sm should reach equilibrium in about 50 days.

Since nuclear fuel is used for several years in a power reactor, (burnup) the final amount of ¹⁵¹Sm in the Sr-90.

Samarium-151

See also