arXiv subjects

W. Suganuma

Publications and source records attributed to W. Suganuma.

4 recordsLinked to original sources

arXiv2005

Dark matter search experiment with CaF2(Eu) scintillator at Kamioka Observatory

We report recent results of a WIMP dark matter search experiment using 310g of CaF2(Eu) scintillator at Kamioka Observatory. We chose a highly radio-pure crystal, PMTs and radiation shields, so that the background rate decreased considerably. We derived limits on the spin dependent WIMP-proton and WIMP-neutron coupling coefficients, a_p and a_n. The limits excluded a part of the parameter space allowed by the annual modulation observation of the DAMA NaI experiment.

astro-ph↗

arXiv2004

Dark Matter Search with Direction Sensitive Scintillators

We have carried out the dark matter search with a 116g direction-sensitive stilbene crystal in Kamioka Observatory. With the crystal fixed to the earth, we searched the modulation of thelight output. No modulation signal was found due to the small size of the detector crystal and the higher background rate yet to be eliminated. However, it demonstrated the effectiveness of the method of direction sensitive search for the dark matter with an implementation of the anisotropic organic scintillation crystal.

astro-ph↗

arXiv2004

Dark Matter Search with Direction Sensitive Scintillator

A direction sensitive dark matter detector using organic crystals is being developed. It exploits the anisotropic scintillation efficiency of organic crystals with respect to the direction of nuclear recoils relative to crystallographic axes. A variation of about 7% was observed in the scintillation efficiency of carbon recoils in a stilbene crystal for recoil energies of 30 keV to 1 MeV. We have performed a pilot experiment at Kamioka to prove the feasibility of this method.

astro-ph↗

arXiv2003

Measurements of anisotropic scintillation efficiency for carbon recoils in a stilbene crystal for dark matter detection

It is known that scintillation efficiency of organic single crystals depends on the direction of nuclear recoils relative to crystallographic axes. This property could be applied to the directional WIMP dark matter detector. The scintillation efficiency of carbon recoils in a stilbene crystal was measured for recoil energies of 30 keV to 1 MeV using neutrons from $^7$Li(p,n)$^7$Be and $^{252}$Cf. Anisotropic response was confirmed in low energy regions. The variation of the scintillation efficiency was about 7 %, that could detect the possible dark matter signal.

astro-ph↗