Beta Emitters 
by Energy and 
Half-Life 
By NAOMI A. HALLDEN 
Analytical Branch 
Health and Safety Laboratory 
U. S. Atomic Energy Commission 
New York, N. Y. 
TuHIs TABLE can help identify unknown 
beta emitters whose half-life and beta 
energy have been determined by stand- 
ard laboratory techniques. It also is 
a guide to beta-emitting isotopes for 
applications requiring specific half- 
lives and energies. (A similar table 
for gamma emitters is in preparation.) 
A more detailed compilation of nuclear 
data, such as National Bureau of 
Standards Circular 499 and Supple- 
ments, should be consulted for details 
of these emitters and their decay. 
Emitters of conversion electrons and 
positrons as well as emitters of beta 
rays are included since all these par- 
ticles produce similar effects when ab- 
sorption methods are used to determine 
energy. Where an isotope can decay 
by emission of beta particles of different 
energies, the emitter is listed in the 
energy group corresponding to each 
beta, provided its contribution to total 
beta activity is greater than 5%. 
This is the lower limit of detection of 
typical absorption technique (Harley 
and Hallden, NU, Jan. ’55, p. 32). 
All the betas from one emitter will lie 
in the same half-life interval. 
Only isotopes with half-lives greater 
than 6 hr are listed; in general, a 
shorter half-life limits identification by 
the methods described. 
Daughters with shorter half-lives 
than their parents are listed in italic 
under the half-life of the parent. In 
the natural series, the short-lived 
daughters are listed under the half-life 
of the -nearest antecedent having a 
half-life over 6 hr. U?3? (0.1-0.3 Mev, 
5-10y) should be in italic. 
* * * 
All data used in this compilation are from 
National Bureau of Standards Circular 499, 
including Supplements 1, 2, and 3. 
204 
nucteonics DATA SHEET 
Tb!s4 Autss 
14 Zn? Wa B25 Rett 033 
Th?31 Pa232 Np?38 Np239 
3-5d Tel!9 TelS2 Eyl4s Th1s7 
Yb175 Priss 
Lu!72 Lu!77 337 
= co 
co 
=| 
a y Pd207 Nd22oi Rese? GU Roe? Tc? 1222/Cs3* 
ActiRasze Th?! Pats: Th2™* Np 248 
No. 4 
Isotope Characteristics 
03-05 
}335 Eyi52 Tq180 
CuS? As76 Br?” Br8? 
Cats $n121 Cs129 
T1200 Np?39 
Dye Yb175 Au!9? 
pis. Xe!s3 Ho26 
E169 Lu!77 
Bails! Ba!4° Nd147 Pp2it 
Fes? Ruts Hfts2 
Se*® Co5® 7195 Sh124 
Tass wiss 
Ti Pp212 Pa254 
1133 Gg135 4,194 
Np236 
0.5-0.7 
Fe52 22 pyi01 
Er271 7180 pp212 
Cu Ga7? Nb% 
jiso pt?97 
Sc*® As?! Ga72 
As?? W387 Np239 
Sc*7 y87 [124 
Mn5?2 [131 Cs152 
Tb!61 Pp 209 
Cel4! Pa2ss 
$p 124 Th? {292 
Ta 182 
Lyt74 
Agit° 
Na22 $h125 Cg 134 
cats Euls4 
$19 
Cs 137 
Be! 
