JINST Instrumentation Theses Archive

Ph.D. degree thesis
accepted by Columbia University, New York, USA in 2006

Kaixuan Ni

Supervisor: Elena Aprile

Development of a Liquid Xenon Time Projection Chamber for the XENON Dark Matter Search

 Keywords:

• Liquid detectors
• scintillation and light emission processes (solid, gas and liquid scintillators)
• Large detector systems for particle and astroparticle physics
• Time projection chambers

 Abstract:
This thesis describes the research conducted for the XENON dark matter direct detection experiment. The tiny energy and small cross-section, from the interaction of dark matter particle on the target, requires a low threshold and sufficient background rejection capability of the detector. The XENON experiment uses dual phase technology to detect scintillation and ionization simultaneously from an event in liquid xenon (LXe). The distinct ratio, between scintillation and ionization, for nuclear recoil and electron recoil events provides excellent background rejection potential. The XENON detector is designed to have 3D position sensitivity down to mm scale, which provides additional event information for background rejection.

Started in 2002, the XENON project made steady progress in the R&D phase during the past few years. Those include developing sensitive photon detectors in LXe, improving the energy resolution and LXe purity for detecting very low energy events. Two major quantities related to the dark matter detection, the scintillation efficiency and ionization yield of nuclear recoils in LXe, have been established. A prototype dual phase detector (XENON3) has been built and tested extensively in above ground laboratory. The 3D position sensitivity, as well as the background discrimination potential demonstrated from the XENON3 prototype, allows the construction of a 10 kg scale detector (XENON10), to be deployed underground in early 2006. With 99.5% electron recoil rejection efficiency and 16 keVr nuclear recoil energy threshold, XENON10 will be able to probe the WIMP-nucleon cross-section down to 2 x 10^{-44} cm^2 in the supersymmetry parameter space, after one month operation in the Gran Sasso underground laboratory.