A Measurement of Charged and Neutral Elementary Particles Emitted from Antiproton Annihilation at Rest in Heavy Nuclei
Final technical rept. 1 May 1987-30 Apr 1991
PENNSYLVANIA STATE UNIV UNIVERSITY PARK LAB FOR ELEMENTARY PARTICLE SCIENCE
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The first complete spectrum of neutrons from antiproton induced fission of Uranium has been obtained. Features of the spectrum are explained by three processes emission of prompt ejectiles driven from the nucleus by pions in the intranuclear cascade, evaporation of neutrons from the excited nucleus before fission, and de-excitation of fission fragments. The temperature of the fission neutrons is about 67 higher than normal fission, indicating large residual energy deposited in the fission fragments. Hence, the fission process serves as a window into the excitation process itself. Results have also been obtained on gamma-rays associated with de-excitation of fission fragments after neutron emission. With respect to normal fission, the relative yield of gamma-rays to neutrons is suppressed, but the temperature of the gamma-rays is higher. Energy transfer by pi-zeros in the intranculear cascade initiated by antiproton annihilation at rest in carbon and uranium has been measured. The prospects for initiating multifragmentation and disintegration of heavy nuclei appear good.
- Nuclear Physics and Elementary Particle Physics