Search

Experimental search for the low‐lying 7H resonance was performed in the d(8He,3He)7H reaction with a 8He beam at 42A MeV. No well‐pronounced peak of 7H was observed, but the spectrum has some peculiarities at ∼2 MeV and ∼10.5 MeV above the t+4 n threshold. The d(12Be,3He)11Li reaction simultaneously measured at 71A MeV showed the population of 11Li ground state with the c.m.s. cross section of ≈1 mb/sr.

Recently recoiled proton tagged knockout reaction experiments were carried‐out for 8He at 82 MeV/nucleon. The purpose of the experiment are: (1) Through the core knocked out technique, to study the correlation of the valence neutrons in the ground state of 8He. This should provide new experimental information to the neutron coupling and neutron matter, including the BCS pairing and BEC pairing. (2) Through the valence neutron knocked out technique, to study the resonant states 7He and the related single particle states. This will be complementary to the previous similar measurement but with better selection of the reaction mechanism.Some new recoiled proton telescopes and the forward neutron spectrometer was applied in the experiment. Performance of the detection system and very preliminary experimental results are shown here.

An intermediate energy Deuteron POLarimeter DPOL has been developed at RIKEN. It was designed to measure all components of the deuteron polarization by using the d+C elastic scattering and the charge exchange 1H(d,2p) reaction in a CH2 analyzer. The calibration in 1995 confirmed large vector analyzing powers for the former, and useful tensor analyzing powers for the latter reaction over 230–270 MeV.

The spinflip probability for the reaction 26Mg(3He,tγ)26Al (1+;1.06 MeV) has been measured at E(3He)=53 MeV and θlab=10°. The extracted value is 40.6±3.6%. A microscopic DWBA calculation with empirically determined effective interactions reproduces the observed cross sections fairly well but the spinflip probability poorly.

The tensor analyzing power of the (d,2He) reaction has been measured at 270 MeV. Its usefulness for the spectroscopic study, particularly in identifying Jπ of the spin‐flip dipole states, is demonstrated for a 12C target. The data are reasonably reproduced in terms of the DWBA theory for the three‐body reaction.

The first data of the polarization transfer coefficients DNN(0°) for (p↘,n↘) reactions at 295 MeV by using a newly developed neutron polarimeter (NPOL) are reported. The results are compared with the distorted‐wave impulse approximation (DWIA) calculations with the effective interactions parametrized by Franey and Love (FL). The FL 270 MeV interaction reproduces very well both the differential cross sections and the polarization transfer DNN(0°), while the FL 325 MeV interaction predicts less negative DNN(0°) values. It is found that the tensor part of the FL 325 MeV interaction is too strong at large momentum transfer (Q≂3.4 fm−1).