J. Woo

Scintillation efficiency of nuclear recoil in liquid xenon

Abstract We present the results of a test done with a Liquid Xenon (LXe) detector for “Dark Matter” search, exposed to a neutron beam to produce nuclear recoil events simulating those which would be generated by WIMPs elastic scattering. The aim of the experiment was to measure directly the scintillation efficiency of nuclear recoil. The nuclear recoil considered in the test was in the tens of keV range. The ratio of measured visible energy over the true recoil energy was evaluated to be about 20%, in good agreement with the theoretical predictions.

Detection of scintillation light in coincidence with ionizing tracks in a liquid argon time projection chamber

A system to detect light from liquid argon scintillation has been implemented in a small, ICARUS-like, liquid argon time projection chamber. The system, which uses a VUV-sensitive photomultiplier to collect the light, has recorded many ionizing tracks from cosmic-rays in coincidence with scintillation signals. Our measurements demonstrate that scintillation light detection can provide an effective method for absolute time measurement of events and eventually a useful trigger signal

Calibration of BC501A liquid scintillator cells with monochromatic neutron beams

Abstract The recoil proton energy response has been measured by exposing cylindrical cells, filled with BC501A BICRON liquid scintillator, to mono-energetic neutron reference fields. We determine the required calibration parameters and report the detailed procedures for the experimental data handling. A dedicated Monte Carlo simulation of the detector response and efficiency has been performed. It showed good agreement with the measured quantities. The results from this calibration are necessary for a detailed study of the neutron spectrum at the underground Gran Sasso Laboratory, with a neutron detector made of 32 liquid scintillator cells, like those used during the calibration.

Performance of the 10 m 3 ICARUS liquid argon prototype

Abstract We report on the performance of a liquid Argon Time Projection Chamber, operating in a 10 m 3 cryostat. This device built in the framework of the ICARUS T600 programme to serve as a full test facility for the adopted cryogenics and mechanical solutions, was successfully tested in 2000 as the last step before the tests of the first 600 t ICARUS module 1 year later. In a final run at the Gran Sasso Laboratory, whose outcome provides the main subject of this paper, also the readout and imaging capabilities of the installed wire chamber and the overall performance of the detector have been successfully tested.

ICARUS. A status report

Abstract The latest evolutions of the ICARUS project are reviewed. During the present year the collaboration has been heavily involved into the construction of the first full scale prototypes of the 600 ton ICARUS detector. Cryogenic and purification tests as well as mechanical tests on a wires chamber module, are presently under completion. No major problems were found and we foresee to be ready for the commissioning of the major detector components by the end of the present year. Also, the Long Baseline Neutrino Oscillation program has been subject to a rapid acceleration. Following our formal proposal, submitted and approved at the beginning of this year by the CERN SPSLC, a working group has been formed to study the details of the beam and a sensitive program has been formulated by which first neutrinos can be sent to the Gran Sasso at the end of year 2001.

ICARUS 600 ton: A status report

The goal of the ICARUS Project is the installation of a multi-kiloton LAr TPC in the underground Gran Sasso Laboratory. The programme foresees the realization of the detector in a modular way. The first step is the construction of a 600 ton module which is now at an advanced phase. It will be mounted and tested in Pavia in one year and then it will be moved to Gran Sasso for the final operation. The major cryogenic and purification systems and the mechanical components of the detector have been constructed and tested in a 10 m3 prototype. The results of these tests are here summarized.