Study of the reaction238U (?, ??f) atE ?=480 MeV

Abstract

Dedicated to Professor Theo Mayer-Kuckuk on the occasion of his 60th birthdayThe excitation function of the fission probability PI(E~) for 238U has been measured in the reaction 238U(c~, ~'f) at 480 MeV bombarding energy. The reaction mechanism of this reaction is discussed for excitation energies below B,I, the threshold for second chance fission, and above B,I up to Ex = 37 MeV. In comparing with results from fission induced by photons and by particle transfer reactions the (~, c~'f) reaction gives too low values for the fission probability PI at excitation energies well above B,s. The role of the quasi-elastic knock-out process in this reaction is discussed.

Compound-nuclear reaction cross sections from surrogate measurements

“…In the following years, similar techniques were routinely used to study fission properties induced by direct reactions. Measurements were performed using ðd; pfÞ, ð; 0 fÞ, ðt; pfÞ, ðt; dfÞ, ð 3 He; dfÞ, and ð 3 He; tfÞ reactions to determine fission thresholds, the excitation-energy dependence of the fission probabilities, and/or the fission-fragment angular anisotropies for many different actinides (Wilkins, Unik, and Huizenga, 1964;Britt et al, 1965;Britt and Plasil, 1966;Specht, Fraser, and Milton, 1966;Britt, Rickey, and Hall, 1968;Wolf, Vandenbosch, and Loveland, 1968;Cramer, 1969, 1970;Cramer and Britt, 1970b;Back et al, 1974aBack et al, , 1974bGavron et al, 1975;Van Der Plicht et al, 1980;Wu et al, 1981;David et al, 1987;Sinha et al, 1992). These experiments used semiconductor detectors for both light-ion and fission-fragment detection.…”

The study of prompt and delayed muon induced fission

“…The energies of muonic 2p -1 s and 3 d-1 s spontaneous fission (m) [12] and 2+lPu(n,f), E, = 1..6 MeV (,) [22] radiationless transitions responsible for prompt muonic fission lie in this region. The energies of muonic 2p -1 s and 3 d-1 s spontaneous fission (m) [12] and 2+lPu(n,f), E, = 1..6 MeV (,) [22] radiationless transitions responsible for prompt muonic fission lie in this region.…”

“…A hadron induced fission study performed for this purpose is reported in [12], the results of which are used here. A hadron induced fission study performed for this purpose is reported in [12], the results of which are used here.…”

“…The details of these hadronic studies will be published elsewhere [12]. Providing results for comparison, virtually free of systematical errors, the reactions 235U, 237Np (e, 0(f) and spontaneous fission of 242pu were measured using the same targets as for muon induced fission.…”

The study of prompt and delayed muon induced fission

“…Equation (3) has already been presented in [39] and is extended here for the average kinetic energy of the emitted neutrons. The ratios F,/F/for the final nuclei are deduced from various measurements (i.e.…”