S. Kakigi

Alpha spectroscopic factors for 6Li, 7Li, 9Be and 12C from the (p, pα) reaction at 296 MeV

Abstract Three-body breakup cross sections and analyzing powers for the 6Li, 7Li, 9Be and 12 C ( p ,pα) reactions were measured at an incident energy of 296 MeV. Data were analyzed using the plane wave impulse approximation (PWIA) and the distorted wave impulse approximation (DWIA) and compared with previous studies. DWIA calculations reproduce shapes of projected spectra and analyzing power distributions fairly well with the exception of the 12 C ( p ,pα) 8 Be reactions. Extracted spectroscopic factors for 6Li, 9Be and 12C are larger than those found in the previous studies. In contrast, extracted spectroscopic factors for 7Li agree with the previous work. This work suggests that the spectroscopic factor for 6Li is ∼ 0.8, independent of incident energies and reaction types.

Electron storage ring, KSR for light source with synchrotron radiation

A small electron storage ring (KSR) in a race track shape with the triple bend doubly achromatic lattice and a circumference of 25.7 m is now under construction. Its maximum energy and radius of curvature in the bending section is 300 MeV and 0.835 m, respectively. The critical wavelength of the radiation from the dipoles is 17 nm. In order to enable future installation of a insertion device for much shorter wavelength, two long straight sections, 5.62 m in length are provided. The magnet system consisting of dipole, quadrupole and sextupole magnets are already aligned with precision of a few tenth mm.

Deuteron breakup with 3He at 89.4 and 118.9 MeV

Quasifree processes were studied by measuring coincident energy spectra for the 2H(3He, 3Hep)n, 2H(3He, tp)p and 2H(3He, dd)p reactions at 89.4 and 118.9MeV. The spectral shape was reproduced with two types of spectator model, that is, a three-body model (TBM) and a four-body model (FBM). The latter contains the effects of projectile breakup processes. Angular correlations of peak cross sections were explained by calculations in the FBM in contrast with those in the TBM. The absolute cross sections were not explained by either model.

A 100 MeV injector for the electron storage ring at Kyoto University

An electron linear accelerator has been constructed at Kyoto University, which is an injector for the 300 MeV storage ring. The output beam energy from the injector is 100 MeV and the designed beam current is 100 mA at the pulse width of 1 /spl mu/sec. The component test is underway. The electron beam of 300 mA is extracted from the electron gun and the peak RF power of 20 MW is successfully fed to the accelerating structures at the pulse width of 2 /spl mu/sec.

Quasifree scattering in the 6Li(α, 2α)2H reaction at Eα between 77 and 119 MeV

Abstract The 6 Li(α, 2α) 2 H breakup reaction has been measured at E α = 77−119 MeV in coplanar, symmetric geometry. The projected energy spectra of the 2α correlation maps on the E 1 axis were obtained and analyzed with DWIA and PWIA calculations. The positions of the quasifree-scattering peaks are well reproduced by both calculations, which at the higher incident energies reproduced well the widths of the experimental peaks. At lower energies, the widths obtained from the DWIA calculation are wider than those observed. Spectroscopic factors, S α d , for breakup into α + d deduced from the DWIA calculation averaged 0.58. Effective numbers of α-clusters, N eff , deduced from the PWIA calculation averaged 0.22.

Multiple scattering effect for quasifree scattering in the 3He(p, pp)2H reaction at 64.8 MeV

Abstract For the 3 He(p, pp) 2 H reaction at 64.8 MeV, angular correlations have been measured in the quasifree scattering region. Angular dependence of the ratio of the cross sections measured to those calculated in the plane-wave impulse approximation is well reproduced by a calculation taking account of the double-scattering effect.

Breakup of 3He with 59.6 MeV vector-polarized deuterons at dp quasifree-scattering conditions

Abstract The 3 He breakup reaction has been studied with 59.6 MeV vector-polarized deuterons at dp quasifree-scattering (QFS) conditions. In the coincidence energy spectra, large bumps corresponding to the QFS were observed. The calculation in the simple plane-wave impulse approximation (PWIA) qualitatively reproduces the energy spectra, but for the absolute cross sections, the ratio of the experimental values to the calculated values in the PWIA is about 0.27. As for the analyzing powers, the experimental values are greatly reduced as compared with the dp elastic-scattering data. The multiple-scattering effect has been investigated by a calculation taking account of the effects of double-scattering terms on the cross sections and the analyzing powers.

Energy spectra of deuterons and protons for the d + d reaction at 60 MeV

Abstract Three-body break-up reactions were studied by measuring continuum energy spectra of particles emitted in the d + d reaction at 60 MeV. The absolute cross section and the angular dependence of the observed large enhancement were reproduced by the theoretical calculation in the single scattering four-body model.

Quasifree processes in the 6Li breakup reactions by alpha particles

Abstract The differential cross sections for the 6 Li(α, 2α) 2 H and the 6 Li(α, 3 He 5 He) 2 H reactions have been measured at the bombarding energy of 118.4 MeV. For both reactions, enhanced quasifree peaks were observed. The angular dependences of the two-body cross sections, deduced from the three-body cross sections by using DWIA, were compared with the free cross sections. For the 6 Li(α, 2α) 2 H reaction, the angular dependence for the quasifree scattering was similar to that for the free elastic scattering and the absolute cross sections were explained with a reasonable αd cluster probability in 6 Li. So the quasifree scattering process seems consistent with the free scattering. For the 6 Li(α, 3 He 5 He) 2 H reaction, the angular dependence for the quasifree reaction process agreed with that for the free reaction; however, the absolute cross sections were about twice as large as those for the free reactions. This might be due to three-body structure effects in 6 Li.

Longitudinal beam emittance monitor for 433 MHz proton linac

We have developed a longitudinal emittance monitor for a 7 MeV proton beam provided by the 433 MHz linac at the Institute for Chemical Research, Kyoto University. In the present system, the beam first hits a thin gold target on the beam line, and a fraction of the scattered protons comes into a small cavity. After deflected by a rf electric field in the cavity, the protons finally reach a position sensitive detector (PSD). The PSD gives the information of the energy and position of the individual scattered proton, which enables us to reconstruct the longitudinal distribution of the beam before colliding with the target. The phase and energy resolution of the system are estimated to be 13° and 23 keV full width at half‐maximum, respectively. The longitudinal rms emittance measured was 0.39±0.07 π deg MeV under the nominal operating condition of the linac.