M. Nakano

Hole strengths and spreading widths observed in 92Mo(p, d)91Mo reaction at 65 Me V

Abstract Differential cross sections and analyzing powers have been measured for the 92 Mo ( p , d ) 91 Mo reaction with a polarized proton beam of 65 MeV incident energy for investigating the level structure of 91Mo up to 10 MeV. The data analysis with the standard DWBA theory provides transferred angular momenta lj values and spectroscopic factors for 42 transitions to the single-hole 1 g 9 2 , 2 p 1 2 , 2 p 3 2 , 1 f 5 2 and 1 f 7 2 st analog states. The spreading widths are deduced and compared with theoretical predictions for discussing the damping mechanism of the single-hole states.

Reducing Energy Degradation Due to Back‐bombardment Effect with Modulated RF Input in S‐band Thermionic RF Gun

Energy degradation due to back‐bombardment effect is quite serious to produce high‐brightness electron beam with long macro‐pulse with thermionic rf gun. To avoid the back‐bombardment problem, a laser photo cathode is used at many FEL facilities, but usually it costs high and not easy to operate. Thus we have studied long pulse operation of the rf gun with thermionic cathode, which is inexpensive and easy to operate compared to the photocathode rf gun. In this work, to reduce the energy degradation, we controlled input rf power amplitude by controlling pulse forming network of the power modulator for klystron. We have successfully increased the pulse duration up to 4 μs by increasing the rf power from 7.8 MW to 8.5 MW during the macro pulse.

Fragmentation of neutron-hole strengths in 59Ni observed in the 60Ni(p,d) 59Ni reaction at 65 MeV

Abstract The 60Ni(p, d) 59Ni reaction has been studied with 65 MeV polarized protons. Angular distributions of the differential cross section and analyzing power have been measured for neutron hole states in 59Ni up to the excitation energies of 7 MeV. The data analysis with a standard distorted-wave Born approximation theory provides transferred angular momenta l, j and spectroscopic factors for thirty-nine transitions. The nuclear damping mechanism of the single hole states is discussed.

Single-particle states in 59Ni with 58Ni(d, p)59Ni reaction at 56 MeV and neutron-bound-state complex potentials

Abstract Angular distributions of the cross sections and analyzing powers were measured for the 58Ni(d,p)59Ni reaction up to the excitation energy of 10 MeV in 59Ni with a high-resolution polarized deuteron beam at 56 MeV. Spins and parities were assigned for 33 discrete levels up to the excitation energy of 8 MeV. Spectroscopic factors, single-particle energies and spreading widths of 1 f 5 2 , 2 p 3 2 , 2 p 1 2 , 1 g 9 2 states were obtained. Neutron-bound-state complex potentials have been calculated from the resultant spreading widths and energies together with results from other one-nucleon transfer-reaction experiments on nickel and calcium isotopes. It is found that the energy dependence of the spreading widths of the single-particle and -hole states and then the imaginary parts of the bound-state potentials in the excitation energy region of 0–10 MeV show a symmetrical behavior with respect to the Fermi surface.

Classical vector analysis to study angular momentum of evaporated protons

The classical vector analysis is proposed to deduce angular momenta of evaporated protons from medium-energy proton-nucleus reactions. The intranuclear cascade model is applied to extract the angular momentum vector of highly excited nucleus, which is in equilibrium after the cascade process. The mixing ratios of angular momenta are determined to fit experimental angular distributions. Resultant ratios show clear tendency in terms of target mass.