Detection Efficiency of NaI(Tl) Detector in 511–1332 keV Energy Range

Table 1

The present activity and half-life of the radioactive sources used to obtain energies.

Nuclide	Activity (micro Ci)	Half-life (day)
^22Na	0.706	950.8
^54Mn	0.348	312.3
^137Cs	0.970	11020.0
^60Co	0.843	1925.5