A crystal spectrometer for neutron measurements has been developed which has relatively good resolution over an effective energy range from 0.08 to >20 ev. The figure of merit which has been obtained is 0.171 μsec/m with Be (123̄1) and 0.127 μsec/m with Be (224̄2) monochromator. The good resolution is made possible by a multiple channel collimator (Soller slit) of novel design. The collimator is described in detail and the resolution function for the system is derived and discussed. It is shown that the resolution of the system is essentially independent of the mosaic spread of the crystal. Experimental results are presented which illustrate the performance of the instrument.
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Bollinger
, Harris
, Hibdon
, and Muehlhause
, Phys. Rev.
92
, 1527
(1953
).12.
Seidl
, Hughes
, Palevsky
, Levin
, Kato
, and Sjöstrand
, Phys. Rev.
95
, 476
(1954
).13.
In both types of instruments complications enter at low energy which cause a departure from this approximate law.
14.
These instruments are: the time‐of‐flight spectrometer at KAPL (Yeater, Gaerttner, and Kelly, unpublished);
the fast chopper at ANL (Bollinger and Cote, unpublished);
the fast chopper at BNL (
Harvey
, Hughes
, Carter
, and Pilcher
, Phys. Rev.
99
, 10
(1955
);and the fast chopper at MTR (Fluharty and Simpson, unpublished).
15.
16.
17.
J. M.
Hastings
and L. M.
Corliss
, Revs. Modern Phys.
25
, 114
(1953
).18.
D. J. Hughes, Pile Neutron Research (Addison‐Wesley Publishing Company, Inc., Cambridge, Massachusetts, 1953), p. 292.
19.
20.
21.
22.
R. E. Wood and H. L. Foote, Jr. (unpublished).
23.
A satisfactory curve was determined from the experimental assembly material mentioned above. See Fig. 9 for shape of the parabolic curve used.
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© 1956 The American Institute of Physics.
1956
The American Institute of Physics
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