Spin-dependent observables in surrogate reactions

Abstract

Observables emitted from various spin states in compound U nuclei are investigated to validate usefulness of the surrogate reaction method. It was found that energy spectrum of cascading γ-rays and their multiplicities, spectrum of evaporated neutrons, and mass-distribution of fission fragments show clear dependence on the spin of decaying nuclei. The present results indicate that they can be used to infer populated spin distributions which significantly affect the decay branching ratio of the compound system produced by the surrogate reactions. * Electronic address: chiba.satoshi@jaea.go.jp

Development of a measurement system for the determination of (n,γ) cross-sections using multi-nucleon transfer reactions

“…The former γ-rays were used to determine branching ratio of the (n; γ) process, and the latter ones provided evidence to support the identities and excitation energies of the compound nuclei deduced from the kinetic energies and emission angles of the outgoing particles measured by the Si ΔE-E detector system. These γ-rays observed by the LaBr 3 (Ce) spectrometers are expected to provide information on spin distribution of compound nuclei populated in surrogate reactions [42]. The present study demonstrates high capability of new apparatus to measure the γ-rays from highly excited states produced by surrogate reactions and to demonstrate the feasibility of SRM experimentally.…”

“…[4][5][6]. To reduce the effect of the differences in the spin-parity distributions between the neutron-induced and surrogate reactions, further investigation, such as measurement of the spectra of evaporation neutrons and emitted γ-rays, the γ-ray multiplicity and so on [42], is necessary.…”

A Comprehensive Approach to Estimate Delayed-neutron Data of Actinides and Minor-actinides

“…Validity of this method is also discussed intensively in Refs. [6,7,1]. In this project, we work primarily with the surrogate method using heavy-ion projectiles to determine mass distribution of fission fragments from minor actinides.…”

Surrogate Reactions Research at JAEA/Tokyo Tech

“…Ref. [9] also proposes some spin-dependent observables to infer populated spin distributions in the surrogate method. …”