Showing papers by "Claude Leroy published in 2003"
11 Oct 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the authors showed that the initial doping concentration in HTLT(TD) silicon detectors is twice more than that of standard silicon detectors (same starting material, but no HTLT process).
Abstract: Silicon detectors have been made on oxygenated silicon with the incorporation of thermal donors during the oxidation process based on BNL's high-temperature long-time (thermal donor) (HTLT(TD)) technology. The initial doping concentration in HTLT(TD) silicon detectors is twice more than that of standard silicon detectors (same starting material, but no HTLT process), with TD being the dominant donor. Standard and HTLT(TD) silicon detectors have been irradiated by 10 MeV protons up to 2.5×10 14 p / cm 2 . It has been found that the increase rate ( β ) of the space charge concentration ( N eff ) after space charge sign inversion (SCSI) in HTLT(TD) silicon detectors is about half of that in standard silicon detectors. Further improvement in proton radiation hardness has been observed in terms of the SCSI fluence. The SCSI fluence for HTLT(TD) silicon detectors is more than four times higher than that of standard detectors, although the corresponding ratio of initial space charge concentrations between the two groups of detectors is about two. This result implies that the SCSI is greatly delayed in HTLT(TD) silicon detector compared with silicon detectors with similar initial space charge (all phosphorus) concentration (lower resistivity standard silicon detectors).
3 citations
TL;DR: The Picasso project as discussed by the authors is a dark matter search experiment based on the superheated droplet technique, which has been successfully applied to the search for weakly interacting cold dark matter particles.
Abstract: The Picasso project is a dark matter search experiment based on the superheated droplet technique. Preliminary runs performed at the Picasso Lab in Montreal have showed the suitability of this detection technique to the search for weakly interacting cold dark matter particles. In July 2002, a new phase of the project started. A batch of six 1-liter detectors with an active mass of approximately 40g was installed in a gallery of the SNO observatory in Sudbury, Ontario, Canada at a depth of 6,800 feet (2,070m). We give a status report on the new experimental setup, data analysis, and preliminary limits on spin-dependent neutralino interaction cross section.
3 citations
Posted Content•
TL;DR: The PICASSO project as mentioned in this paper uses superheated freon liquid droplets (active material) dispersed and trapped in a polymerized gel for cold dark matter (CDM) search.
Abstract: The PICASSO project is a cold dark matter (CDM) search experiment relying on the superheated droplet technique. The detectors use superheated freon liquid droplets (active material) dispersed and trapped in a polymerized gel. This detection technique is based on the phase transition of superheated droplets at room or moderate temperatures. The phase transitions are induced by nuclear recoils when undergoing interactions with particles, including CDM candidates such as the neutralinos predicted by supersymmetric models. The suitability of the technique for this purpose has been demonstrated by R&D studies performed over several years on detectors of various composition and volume. Simulations performed to understand the detector response to neutrons and alpha particles are presented along with corresponding data obtained at the Montreal Laboratory.
1 citations