ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract With the time-integral perturbed angular correlation (TIPAC) method the pressure dependence of the perturbation of the 121.1–279.5 keV γ-γ cascade in75As has been investigated using gaseous H2 75Se sources in different buffer environments. The obtained attenuation coefficients G22 (∞) in the range of 0.55 to 1.0 were fitted with a theoretical stochastic model. In the region of low density, where the correlation time τC is large compared to the lifetime τ of the intermediate level of the nucleus, charge transfer collision cross sections have been evaluated between 8.1·10−16 cm2 for He, 1.3·10−14 cm2 for Xe and 1.8·10−14 cm2 for the molecular H2 buffer gas. For increasing densities of the buffer gases the correlation time τC became small compared to the intermediate lifetime τ. The main effect in this region is the depolarization, and we found cross sections between 5.2·10−15 cm2 for He, 8.7·10−14 cm2 for Xe and 1.2·10−13 cm2 for the H2 buffer gas.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01027259
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