Tadafumi Kishimoto

Kaonic Nuclei Excited by the ( K − , N ) Reaction

We show that kaonic nuclei can be produced by the (

The superconducting kaon spectrometer — SKS

{K}^{\ensuremath{-}},p

Limits on the annual modulation of WIMPs-nucleus scattering with large-volume NaI(Tl) scintillators

) and (

The (pi+,K+) reaction and light Lambda hypernuclear spectroscopy

{K}^{\ensuremath{-}},n

Pre-Equilibrium Deexcitation Process for 164Dy(α, xn γ) Reaction and Angular Momentum Transfers

) reactions. The reactions are shown to have cross sections experimentally measurable. The observation of kaonic nuclei gives a kaon-nucleus potential which answers the question as to the existence of kaon condensation in dense nuclear matter, especially in neutron stars.

Experimental Investigation of Thermal Neutron-Induced Single Event Upset in Static Random Access Memories

A superconducting kaon spectrometer has been installed in the north experimental hall of the KEK 12-GeV proton synchrotron. The spectrometer was designed to serve for nuclear physics experiments with meson beams in the 1 GeV/c region, particular emphasis being laid on study of Λ-hypernuclei via (π+, K+) reactions. In order to obtain Λ-hypernuclear data with better statistics and energy resolution, it was designed to have a good momentum resolution of 0.1% FWHM and a large acceptance of 100 msr. It consists of a large superconducting dipole magnet, tracking chambers, and trigger counters that can efficiently select kaons from large background of pions and protons. The overall energy resolution for scattering is realized together with a beam-line spectrometer in the K6 beam line, the momentum resolution of which was also designed to be better than 0.1% FWHM. A good energy resolution of better than 2 MeV FWHM has been confirmed in π−-12C elastic scattering and in the (π+,K+) reaction on 12C.

Angular Momentum Transfers in Equilibrium and Pre-Equilibrium Dy(α, xn γ) Reactions

Abstract A search for cold dark matters has been carried out with the 662 kg NaI scintillator array of ELEGANT V at the Kamioka underground laboratory. The annual modulation of weakly interacting massive particles (WIMPs) energy spectra has been investigated. No significant modulations beyond statistical fluctuations were found. Stringent limits were obtained on masses and cross sections for both axial-vector coupled and vector coupled WIMPs.

Search for the H dihyperon by double weak decay of nuclei

Abstract High-quality excitation-energy spectra of Λ 7 Li, Λ 9 Be, Λ 13 C and Λ 16 O as well as Λ 12 C have been obtained with 2 MeV (FWHM) resolution and good statistics through the (π + ,K+) reaction. The spectra of Λ 12 C, Λ 16 0 and Λ 13 C are discussed in relation to the ΛN spindependent interaction, and those of Λ 9 Be and Λ 7 Li within the framework of the cluster structure of Λ hypernuclei. It is emphasized that Λ hypernuclear spectroscopy provides us with valuable information on Λ hypernuclear structure and the ΛN interaction.

A broad range spectrometer PIK for medium-energy meson spectroscopy

Pre-equilibrium deexcitation process for the 164 Dy(α, x n γ) reaction at E α =90 MeV was studied by means of γ-γ and neutron-γ coincidence method. Properties of the preequilibrium phase were deduced as a function of the neutron multiplicity x . The reaction process was analyzed in terms of the two-phase deexcitation process, the pre-equilibrium phase with the energy parameter (quasi-temperature) of k T p =5 MeV and the equilibrium phase with the temperature of k T e =1.2 MeV. Angular momenta removed by the decaying neutrons at the pre-equilibrium and equilibrium phases, together with the data of the γ-ray multiplicity, account for the angular momenta introduced by the projectile.

A new high energy gamma radiation measuring system (HERMES)

Static random access memories (SRAMs) with a borophosphosilicate glass film (BPSG) and with a normal silicon oxide film (non-boron-doped silicon oxide film) were fabricated, and the influence of a BPSG film on the neutron-induced single event upsets (SEUs) was investigated. It was confirmed that the thermal neutron reactions on boron atoms in a BPSG film induce SEUs. The SEU rate depends strongly on cell charge and increases as the cell charge decreases. In future SRAMs with a small cell size and low operating voltage, the thermal neutron reaction on boron atoms in a BPSG film will play a significant role to the neutron-induced single event upsets.