dark matter forms a giant sea, enclosing the milky way. the earth and solar system like a small...
TRANSCRIPT
Dark matter forms a giant sea, enclosing the milky way. The earth and solar system like a small fish, swimming in it.
Dark Matter particle has a small probability hitting the atomic nuclei (<1time/100kg day ), producing atomic recoil , Direct detection of dark matter is to detect the
Signals produced by this type of atomic recoil.
Semi-Conductor ( Ge , Si ) Electric current and heat Low -T ( 0.02K )、 high-cost , hard to scale
Crystal ( NaI , CsI ) light Hard to rule out background
Noble gas-liquid (Xe , Ar ) Light and electrons Good to distinguish signals , ton scale
Can detect both light and electron: light : through PMT electrons : strong electric field+ gas phase
Large target : large target has self-shielding effects Large atomic mass
Cross section is proportional to the square of A Can be purified easily Is complementary to the semi-conductor tech
Upgrade of XENON10 Lower background than
XENON10 by 100 times, background 0.005 event / kg day kev
Can discriminate gamma and nucear recoil by 99.5%
Continuous running since jan 2011
Started in 2009 Major Institutions
Shanghai Jiaotong University Shanghai Inst. of applied physics Shangdong University Peking University University of Michigan University of Maryland
JinPing Hydropower plant has four water-passage tunnels of 13m diameters,
two traffic tunnels of 6m diamters.
Length of the tunnel, 17km Maximum depth 2400m (6000-7000 wm).