Dark Matter Experiment

We know that about 23% of the total energy and matter of the Universe is dark matter, but we do not know what that is made of. The aim of the dark matter search experiment, XMASS, is to directly observe interactions of the cold dark matter in the large detector placed underground and to reveal the character of dark matter -- its interactions, mass and so on. We use 1 ton liquid Xenon detector cooled down at the temperature of -100 degree Celsius and measure the scintillation light emanated from the interaction of the dark Matter in the detector. The experimental sensitivity is about 2 orders of magnitude better than the current best limit. We hope that we will step in to the discovery region.

In 2008, an underground cavity to house the experiment was completed and following that, the 10m high cylindrical water tank which contains 800 tons of water to shield gamma rays and neutrons from nearby rocks was constructed. The major parts of the detector will be constructed during the summer and autumn in 2009. We aim to start the experiment in November, 2009.

Group Member

Kai Martens

Identification of particle candidates for Dark Matter. Super low background experiments.

Shigetaka Moriyama

Direct detection of Dark Matter.

Masayuki Nakahata

Purification of Xenon for low background experiments.

Yoichiro Suzuki

Discovery of Dark Matter.

Yasuo Takeuchi

Dark Matter search at XMASS.