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Title: Indium-115(n,n/sup 1/) and /sup 90/Zr(n,2n) activation rate measurements on multiple thickness beryllium and lead slabs

Conference · · Trans. Am. Nucl. Soc.; (United States)
OSTI ID:5589239

Most of the published design studies of fusion and hybrid blankets have proposed lead or beryllium as neutron multipliers. In view of the important role played by these two, it is vital to have reliable neutron cross-section data for them. Of late, there have been some more differential and integral measurements, but there seems to be considerable disagreement as to the adequacy of the data. Hence, there is a need for more measurements. Recently the activation rates were measured along the axis of the Haefely generator-multiplier (18-cm-thick Be/15-cm Pb) assembly. The individual slabs were each kept at 10 cm from the flat surface of the generator. /sup 90/Zr(n,2n) was used instead of /sup 58/Ni(n,2n) as the former has higher activation cross section; the threshold is nearly the same for the two. The measured and computed profiles were compared and it was found that both agreed within 10%. The radial profiles of zirconium and indium activation rates (determined per source neutron per detector nucleus) using the DOT3.5 code and the 46-group cross-section library with P/sub 3/-S/sub 16/ approximations have been computed. The source intensity value was deduced for each experiment by least-squares fitting of measured zirconium activation rates as a function of the computed rates. It is to be noticed that, in general, there is a good agreement between the measured and computed values up to /approx/25 cm. Beyond this radius, there is considerable disagreement between the two, in particular for In/Zr activity ration. 11 refs., 3 figs.

OSTI ID:
5589239
Report Number(s):
CONF-8711195-
Journal Information:
Trans. Am. Nucl. Soc.; (United States), Vol. 55; Conference: American Nuclear Society winter meeting, Los Angeles, CA, USA, 15-19 Nov 1987
Country of Publication:
United States
Language:
English