Abstract
In this study, experiments were designed and performed to determine v for U-235, Np-237 and Am-243 in a fast neutron spectrum. Neutron emission measurements were performed at the University of Missouri Research Reactor ( ) using a 144 KeV (silicon) filtered neutron beam. The measurements were conducted in two stages. The first stage consisted of preliminary experiments to confirm and improve the design of the apparatus and procedures for the second stage measurements. The second stage consisted of performing neutron emission and fission rate measurements. The neutron emission rates from the actinide samples were observed using three proton recoil detectors. The detection system's efficiency was determined using a Cf-252 source. Fission rate measurements for U-235, Np-237, and Am-243 were performed using solid state nuclear track detectors (SSNTDs). The measured values of v in the fast spectrum of the silicon filtered neutron beam for U-235, Np-237, and Am-243 were found to be 2.5117 ︢0.0574 3.13040︢.1218, and4.00350︢.347 respectively Delayed neutron yields and decay constants for U-235, Np-237, Am-241, and Am-243 were measured at the Texas A&M University TRIGA reactor using a fast pneumatic transfer system, The detection system consisted of an array of BF3 proportional counters embedded in a polyethylene cylinder. The measured values of the total yield from thermal neutron induced fission of U-235, Np-237, Am-241, and Am-243 were determined to be 0.01540︢.00042, 0.01260︢.000387, 0.004350︢.000184and 0.00813 ︢0.000155 respectively. The measured values of v for the actinide isotopes were compared with the values of v in the ENDF/B-VI library. The value of v for U-235 is in a good agreement with the ENDF/B-VI value. The newly measured values of v for Np-237 and Am-243 are higher than the values in the ENDF/B-VI. The newly measured values of delayed neutron group parameters and total yields were compared with other values recommended by Keepin, Waldo et. al., Benedetti et. al. and Tuttle. Very good agreement was obtained especially for U-23 5.
Saleh, Habeeb H. (1995). Neutron emission measurements from actinide waste isotopes. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1560099.