Vg. Alpatov et al., A SETUP FOR DETECTION OF MOSSBAUER SELF-ABSORPTION OF GAMMA-QUANTA OFA AG-109M LONG-LIVED ISOMER, Instruments and experimental techniques, 40(6), 1997, pp. 753-757
The setup is designed for searching for Mossbauer self-absorption of 8
8-keV gamma-quanta from Ag-109m in a single-crystal source-absorber by
comparing the temperature dependences of gamma-quanta yields int he h
orizontal and vertical directions. If the gamma-resonance broadening i
s small, then the gravitational red shift restricts the effective reso
nant absorption length in the vertical gamma-ray beam. The setup inclu
des a small-sized cryostat, two Ge(Li) detectors, and a system compens
ating for the vertical component of the Earth's magnetic field. By per
iodically switching this system on and off, one may observe a synchron
ous modulation of the resonant absorption probability in the horizonta
l direction. The expected decrease in the gamma-ray intensity int he h
orizontal beam as a results of the Mossbauer effect is similar to 5 x
10(-4) for a gamma-source cooled from 77 to 4.2 K. For the vertical be
am, such as decrease is similar to 7 times smaller.