New observations of stimulated emission of Mössbauer radiation in isomeric transitions $$^{125m_2 } Te \to ^{125m_1 } Te + hv(109.3 keV)$$ and $$^{123m_2 } Te \to ^{123m_1 } Te + hv(88.46 keV)$$

Abstract

Summary. --A sample of Be 125m2Te containing (4.9 _+ 1.5). 10 TM atoms/era 3 of 125"~Te was obtained in a reactor by neutron activation of polycrystalline beryllium telluride Be124Te. The ratio of the number of 109.27keV photons emitted in the 125~ZTe + hv--,125mlTe + 2hv transition due to attainment of the MSssbauer conditions (at T = 10 K) to the total number of photons produced in the sample at T = 300K was measured to be e~p = Ar162 = 0.0045 + 0.0030. Independent measurements of the intensity of the two-photon 218.54 keV line at 10 K in the same sample yielded a value of 0.0023 + 0.0004 for e~p. Under the conditions of our experiment in the moving-wave approximation (i.e. in the framework of non-stationary optics) the theory predicts the value etheo r =-~coh(10K)/-~non~oh (300 K) = 0.0018 + 0.0006 for the ratio of the superemission power of Te-125me nuclei at 10 K 2cob to the normal spontaneous emission power of these nuclei at 300 K -~non-coh-This value within the error coincides with e~p. The stimulated MSssbauer transition 123~Te + hv(88.46 keV)--~ 123miTe + 2hv(88.46 keV) in a polycrystalline sample of Mga TeO6 containing (3.4 -+ 0.7). 1019 atoms/cm 3 of 128~Te was also experimentally studied. The measured value e~p = (5 -+ 3). 10 -4 for this transition within the error coincides with a theoretical value ethc~r = 0.00023 obtained in the moving-wave approximation.