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Pure Beta Emitters

This is a list of pure beta emitters. These are of interest to those making radioisotope power sources.

These are sorted by half-life.

You can download the data in spreadsheet form here. This will let you sort by other criteria.

There are a handful of isotopes which I would call "almost-pure" beta emitters. These have a gamma abundance of less than 2%. They include As-77, Br-83, La-141, and Cm-249. All have half-lives of less than two days.

One interesting isotope is Ra-228. The half-life is 5.8 years. It has two beta pathways. One has a maximum energy of 14.9 keV and the other is 39.2 keV. There are two gamma pathways, both with energy less than 13.5 keV. The total abundance of the gammas is 5.7%.

All isotopes listed below decay to a stable isotope, unless noted otherwise in the comment column.

isotope half-life (years) max energy (keV) avg energy (keV) abundance comments
cu-66 9.74E-6 2640 1111 1
pb-209 0.00038 644.4 197.5 1
pr-145    0.000685 1805 683 0.95 has many beta decay pathways - only one is shown here
te-127 0.00107 276 78.2 0.012 has multiple beta decay pathways
te-127 0.00107 694 224.7 0.988 has multiple beta decay pathways
sn-121 0.0030 388.9 115.2 1
ni-66 0.0063 227 65 1 decays to Cu-66, a pure beta emitter with a 29 s half-life
y-90 0.007 2281.4 933.7 1
bi-210 0.014 1161.5 389 1 decays to Po-210, an alpha emitter with a 138 d half-life; also has a small alpha decay channel with an abundance of 0.00013%
er-169 0.0258 342.5 98.1 0.45 has multiple beta decay pathways
er-169 0.0258 350.9 100.8 0.55 has multiple beta decay pathways
pr-143 0.037 934.5 315.3 1
p-32 0.039 1710.3 694.9 1
p-33 0.069 248.5 76.4 1
sr-89 0.138 1492 583.3 1
y-91 0.160 340.9 100.8 0.003 has multiple beta decay pathways
y-91 0.160 1545.6 604.9 0.997 has multiple beta decay pathways
w-188 0.190 58 14.9 0.008 has multiple beta decay pathways, decays to Re-188, a beta/gamma emitter with a 17 h half-life
w-188 0.190 285 79.9 0.002 has multiple beta decay pathways, decays to Re-188, a beta/gamma emitter with a 17 h half-life
w-188 0.190 349 99.7 0.99 has multiple beta decay pathways, decays to Re-188, a beta/gamma emitter with a 17 h half-life
s-35 0.240 166.8 48.6 1
sn-123 0.354 314 90.5 0.006 has multiple beta decay pathways
sn-123 0.354 1403 525.5 0.994 has multiple beta decay pathways
ca-45 0.445 256.8 77.2 1
bk-249 0.877 125.7 32.4 1 decays to Cf-249, an alpha/gamma emitter with a 351 y half-life
ru-106 1.0 39.4 10 1 decays to Rh-106, a pure beta emitter with a 30 s half-life and a peak energy of 3.5 MeV
tm-171 1.9 29.7 7.5 0.02 has multiple beta decay pathways
tm-171 1.9 96.4 25.1 0.98 has multiple beta decay pathways
pm-147 2.6 224.6 62 1 decays to Sm-147, an alpha emitter with a very long half-life
kr-85 10.8 173.4 47.65 0.004 has multiple beta decay pathways
kr-85 10.8 687.4 251.6 0.996 has multiple beta decay pathways
h-3 12.3 18.6 5.7 1
cd-113m 14.1 580 185.4 1 also has a small isomeric transition channel with an abundance of 0.14% and a decay energy of 264 keV
pu-241 14.4 20.8 5.2 1 decays to Am-241, an alpha/gamma emitter with a 432 y half-life
sr-90 28.8 546.2 195.8 1 decays to Y-90, a beta emitter with a 2.7 d half life
ar-42 32.9 600 233 1 decays to K-42, a beta/gamma emitter with a 12.4 h half-life
sm-151 90.1 54.8 13.96 0.009 has multiple beta decay pathways
sm-151 90.1 76.3 19.68 0.991 has multiple beta decay pathways
ni-63 100.2 66.9 17.4 1
si-32 172.1 225 68.8 1 decays to P-32, a pure beta emitter with a 14 d half-life
ar-39 269.2 565 218.8 1
c-14 5734 156.5 49.5 1
tc-99 2.1E+05 293.5 84.6 1
se-79 6.5E+05 150.7 55.8 1
be-10 1.5E+06 556.2 202.6 1
cs-135 2.3E+06 205 56.3 1
pd-107 6.5E+06 33 9.3 1
re-187 4.4E+10 2.6 0.7 1
in-115 4.4E+14 497 152 1
cd-113 9.3E+15 316 93.3 1
References