The cross section dependence on energy near a threshold of the reaction Be¿(d,n)B¹⁰
Butler, James Wilford
Master of Arts
A new group of neutrons with negative Q has been reported by Evans, Malich, and Kisser. In these experiments the neutrons were detected with gas recoil proportional counters. One counter contained hydrogen and 2 per cent methane at one atmosphere, and the other was filled with commercial argon at one atmosphere. Both counters showed a rise in the yield curve indicating a new group of neutrons with a Q value of - .74 Mev. A check on the threshold for the new group was obtained by surrounding the argon counter from all directions except the forward with a slab of paraffin. The yield curve exhibited an upward break at 9 kev confirming the thresholds calculated from the first two methods. However, in none of these curves was the upward break sharply defined. The purpose of this investigation was to confirm this threshold with a different counting technique and to develop an optimum counter geometry for detecting new slow neutron thresholds in other reactions. It is hoped that this method of counting might be able to resolve closely residing thresholds in nuclear reactions and thus yield important information on nuclear structure.