In:
Canadian Journal of Physics, Canadian Science Publishing, Vol. 43, No. 10 ( 1965-10-01), p. 1843-1852
Abstract:
A parameter R(v), relevant to velocity-sensitive Mössbauer spectroscopy, has been computed for the case where the orientation of 57 Co nuclei is produced dynamically by the Overhauser effect. This particular pumping scheme for producing nuclear orientation brings out two features. (1) It allows the determination of η, the ratio of flip-flop to flip-flip thermal relaxations, by an experimental measurement of R(v), since the theoretical expressions for R(v) are found to be quite sensitive to the value of η. A numerical evaluation for three cases of overlap between absorber and emitter lines indicates wide variation in R(v) for increasing values of η from 10 −7 to 10 7 : for case (a), R(v) increases monotonically from 8.5 × 10 −7 to 1.07 × 10 6 when emission line 3/2 → 1/2 overlaps absorption line −1/2 → −3/2; for case (b), R(v) decreases monotonically from 1.34 × 10 14 to 8.91 × 10 −5 when emission line −1/2 → 1/2 overlaps absorption line −1/2 → 1/2; and for case (c), R(v) decreases monotonically from 1.62 × 10 2 to 6.14 × 10 −3 when source lines −1/2 → −1/2, 1/2 → −1/2, 1/2 → 1/2, and 3/2 → 1/2 overlap absorber lines −1/2 → −3/2, −1/2 → 1/2, 1/2 → −1/2, and 1/2 → 1/2 respectively. (2) Since these R(v)'s are found to be much different from those that would be achieved through a pumping scheme using the Jeffries–Abragam effect, the possibility of using the Mössbauer effect to distinguish between the various ways of producing the nuclear orientation is suggested.
Type of Medium:
Online Resource
ISSN:
0008-4204
,
1208-6045
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1965
detail.hit.zdb_id:
2021497-2
Bookmarklink