2005 2nd Joint Meeting of the Nuclear Physics Divisions of the APS and The Physical Society of Japan
Sunday–Thursday, September 18–22, 2005;
Maui, Hawaii
Session 2WF: Workshop 6B: Double Beta-Decay and Neutrino Mass
2:00 PM–5:00 PM,
Sunday, September 18, 2005
Ritz-Carlton Hotel
Room: Plantation 3
Sponsoring
Units:
DNP JPS
Chair: Kevin Lesko, Lawrence Berkeley National Laboratory
Abstract ID: BAPS.2005.HAW.2WF.4
Abstract: 2WF.00004 : The EXO-200 detector
3:30 PM–4:00 PM
Preview Abstract
Abstract
Author:
Andrea Pocar
(Stanford University)
EXO-200 is a prototype detector for the Enriched Xenon Observatory (EXO)
searching for double beta decay ($\beta \beta )$ of xenon 136. It employs
200 kg of enriched liquid xenon (enriched to 80{\%} in the isotope Xe-136,
already in hand for the project). The xenon, in liquid phase (LXe) is also
used as active medium contained in an all-Teflon, cylindrical, time
projection chamber (TPC). Currently under construction at Stanford, its
functionality will be tested prior to being housed underground at WIPP, New
Mexico.
EXO-200 will serve as a prototype for the 1-10 ton scale EXO experiment. It
will allow researching low radioactivity building materials, optimizing the
performance and operation of a large-scale xenon detector, and studying some
of its crucial parameters, such as energy resolution. On the other hand,
once completed, it will also be the largest running double-beta decay
experiment. It will not employ the Ba-136 ion tagging technique being
developed for EXO. EXO-200 is designed to have very competitive sensitivity
for the neutrino-less (0$\nu \beta \beta )$ process. It also aims at
measuring the lifetime of the standard, although not yet observed, $\beta
\beta $ decay of Xe-136 accompanied by neutrinos (2$\nu \beta \beta
)$.
Both the ionization signal and the scintillation light produced by ionizing
events in the xenon will be recorded. Such complementary information is
proven to significantly improve the energy resolution of xenon detectors, a
crucial requirement in order to separate the 0$\nu \beta \beta $ and
2$\nu \beta \beta $ processes.
The TPC displays an electric field parallel to the cylinder axis with a
central cathode and two sets of orthogonal wires at each end for 3D position
reconstruction of the events. 700 large area avalanche photodiodes collect
the scintillation light. A double-walled, vacuum-insulated copper cryostat
filled with fluorocarbon fluid surrounds the xenon, providing a significant
buffer for external gamma radiation as well as the necessary cryogenics.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.HAW.2WF.4