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Title: The BiPo detector for ultralow radioactivity measurements

Abstract

The BiPo project is dedicated to the measurement of extremely low radioactivity contamination of SuperNEMO source foils (208Tl < 2 {mu}Bq/kg and 214Bi < 10 {mu}Bq/kg). The R and D phase is started : a modular BiPo prototype with its shielding test facility is under construction. The goal of this prototype is to study the background and particularly the surface contamination of scintillators. The first capsule has been installed in the Canfranc Underground Laboratory in October, 17th and is now taking data. After 10.7 days of measurements, a preliminary upper limit on the surface radiopurity of the scintillators of A(208Tl) < 60 {mu}Bq/m2 (90% C. L.) has been obtained.

Authors:
 [1]
  1. LAL, Universite Paris-Sud 11, CNRS/IN2P3, Orsay (France)
Publication Date:
OSTI Identifier:
21055021
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 897; Journal Issue: 1; Conference: LRT 2006: Topical workshop on low radioactivity techniques, Aussois (France), 1-4 Oct 2006; Other Information: DOI: 10.1063/1.2722062; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BISMUTH; BISMUTH 214; CAPSULES; FOILS; PHOSPHORS; POLONIUM; RADIOACTIVITY; SHIELDING; SOLID SCINTILLATION DETECTORS; SURFACE CONTAMINATION; SURFACES; TEST FACILITIES; THALLIUM 208; UNDERGROUND

Citation Formats

Bongrand, M. The BiPo detector for ultralow radioactivity measurements. United States: N. p., 2007. Web. doi:10.1063/1.2722062.
Bongrand, M. The BiPo detector for ultralow radioactivity measurements. United States. doi:10.1063/1.2722062.
Bongrand, M. Wed . "The BiPo detector for ultralow radioactivity measurements". United States. doi:10.1063/1.2722062.
@article{osti_21055021,
title = {The BiPo detector for ultralow radioactivity measurements},
author = {Bongrand, M.},
abstractNote = {The BiPo project is dedicated to the measurement of extremely low radioactivity contamination of SuperNEMO source foils (208Tl < 2 {mu}Bq/kg and 214Bi < 10 {mu}Bq/kg). The R and D phase is started : a modular BiPo prototype with its shielding test facility is under construction. The goal of this prototype is to study the background and particularly the surface contamination of scintillators. The first capsule has been installed in the Canfranc Underground Laboratory in October, 17th and is now taking data. After 10.7 days of measurements, a preliminary upper limit on the surface radiopurity of the scintillators of A(208Tl) < 60 {mu}Bq/m2 (90% C. L.) has been obtained.},
doi = {10.1063/1.2722062},
journal = {AIP Conference Proceedings},
number = 1,
volume = 897,
place = {United States},
year = {Wed Mar 28 00:00:00 EDT 2007},
month = {Wed Mar 28 00:00:00 EDT 2007}
}
  • The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in {sup 208}Tl and {sup 214}Bi for the SuperNEMO double beta decay source foils. A modular prototype called BiPo-1 with 0.8 m{sup 2} of sensitive surface area has been running in the Modane Underground Laboratory since February 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in {sup 208}Tl. After moremore » than one year of background measurement a surface activity of the scintillators of A({sup 208}Tl) = 1.5 {mu}Bq/m{sup 2} is reported here.Given this level of background, a larger BiPo3 detector having 3.25 m{sup 2} of active surface area, will able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of A({sup 208}Tl)<3-4 {mu}Bq/kg(90% C.L.) with a six month measurement. This detector is actually under construction and will be installed in the Canfranc Underground Laboratory mid 2011.« less
  • New generation experiments in Astroparticle Physics need to operate in really restrictive background conditions, which implies the use of high radiopure materials for the experimental setup construction. For this reason the screening of the materials with enough sensitivity has become a challenge that sometimes cannot be afforded with standard techniques like Germanium detector spectroscopy. BiPo is a dedicated detector, that operates in the Canfranc Underground Laboratory, designed to measure the radiopurity, mainly of the ββ sources of the SuperNEMO experiment, by the detection of BiPo events. It is composed of two modules with 40 optical lines each one, registering themore » energy and the time of the emitted particles. The well known features of the BiPo events (delayed coincidence between an electron and an alpha particle) facilitate the discrimination of other background events that could entangle the expected signal. In addition, the geometry of the detector, with an active area of around 3.6 m{sup 2}, has been optimized to reach the necessary sensitivity levels for the SuperNEMO source foils in the shortest time possible. Preliminary results of background measurements and calibrations taken since summer 2012 shows that the required sensitivity for the measurements of the source foils could be reached in few months. Routine measurements of samples are already started being an important point for the SuperNEMO source foils construction.« less
  • The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in 208Tl and 214Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8m2 of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in 208Tl. After more than one year of backgroundmore » measurement, a surface activity of the scintillators of Að208TlÞ ¼ 1:5mBq=m2 is reported here. Given this level of background, a larger BiPo detector having 12m2 of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of Að208TlÞo2mBq=kg (90% C.L.) with a six month measurement.« less
  • An InGaAs single photon avalanche detector capable of sub-Geiger mode (Photomultiplier-tube-like) operation is reported. The device achieves a stable gain at around 10{sup 6}. The gain fluctuation is greatly suppressed through a self-quenching effect, thus an equivalent excess noise factor as low as 1.001 is achieved. In the photon counting experiment, the device is operated in the nongated mode under a dc bias. Because of its unique characteristics of self-quenching and self-recovery, no external quenching circuit is needed. The device shows a single photon response of around 30 ns and a self-recovery time of about 300 ns.