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Pis'ma v Zhurnal Èksperimental'noi i Teoreticheskoi Fiziki, 2001, Volume 73, Issue 8, Pages 430–433
(Mi jetpl4365)
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This article is cited in 5 scientific papers (total in 5 papers)
FIELDS, PARTICLES, AND NUCLEI
Temperature effect on the decay periods of long-lived $^{\rm 180m}$Hf and $^{\rm 87m}$Sr isomers
V. G. Alpatov, Yu. D. Bayukov, A. V. Davydov, Yu. N. Isaev, G. R. Kartashov, M. M. Korotkov, V. M. Samoilov Institute for Theoretical and Experimental Physics (Russian Federation State Scientific Center), Moscow
Abstract:
Experiments on measuring the decay periods of long-lived $^{\rm 180m}$Hf and $^{\rm 87m}$Sr isomers at room temperature and at $77$ K in massive samples of HfO$_2$, Sr(NO$_3)_2$, and SrCO$_3$ are reported. The isomeric nuclear states were excited by irradiating the samples with neutrons from a Pu-Be source. According to the theory of V. I. Vysotski $et~al$., the $T_{1/2}$ value must increase if a $\gamma$-active nucleus is surrounded by many identical ground-state nuclei, because these distort the spectrum of electromagnetic vacuum oscillations near the nuclear energy level. As the temperature of the sample decreases, $\gamma$-ray lines narrow, especially for the low-energy Mössbauer transitions, thereby enhancing the resonance effect on the spectrum of vacuum oscillations. For the $^{\rm 180m}$Hf isomer, whose upper $\gamma$ transition carries away 57.55 keV, the $T_{1/2}$ value was found to increase by $2.99\pm 0.87$% upon sample cooling. For $^{\rm 87m}$Sr, whose decay scheme has no Mössbauer lines, the relative change in $T_{1/2}$ was found to be $0.77\pm 0.53$%.
Received: 20.03.2001
Citation:
V. G. Alpatov, Yu. D. Bayukov, A. V. Davydov, Yu. N. Isaev, G. R. Kartashov, M. M. Korotkov, V. M. Samoilov, “Temperature effect on the decay periods of long-lived $^{\rm 180m}$Hf and $^{\rm 87m}$Sr isomers”, Pis'ma v Zh. Èksper. Teoret. Fiz., 73:8 (2001), 430–433; JETP Letters, 73:8 (2001), 385–388
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