85 research outputs found
Operation of a high purity germanium crystal in liquid argon as a Compton suppressed radiation spectrometer
A high purity germanium crystal was operated in liquid argon as a Compton
suppressed radiation spectrometer. Spectroscopic quality resolution of less
than 1% of the full-width half maximum of full energy deposition peaks was
demonstrated. The construction of the small apparatus used to obtain these
results is reported. The design concept is to use the liquid argon bath to both
cool the germanium crystal to operating temperatures and act as a scintillating
veto. The scintillation light from the liquid argon can veto cosmic-rays,
external primordial radiation, and gamma radiation that does not fully deposit
within the germanium crystal. This technique was investigated for its potential
impact on ultra-low background gamma-ray spectroscopy. This work is based on a
concept initially developed for future germanium-based neutrinoless double-beta
decay experiments.Comment: Paper presented at the SORMA XI Conference, Ann Arbor, MI, May 200
Focal-plane detector system for the KATRIN experiment
The focal-plane detector system for the KArlsruhe TRItium Neutrino (KATRIN) experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout electronics, two superconducting solenoid magnets, an ultra high-vacuum system, a high-vacuum system, calibration and monitoring devices, a scintillating veto, and a custom data-acquisition system. It is designed to detect the low-energy electrons selected by the KATRIN main spectrometer. We describe the system and summarize its performance after its final installation
The Majorana Project
Building a \BBz experiment with the ability to probe neutrino mass in the
inverted hierarchy region requires the combination of a large detector mass
sensitive to \BBz, on the order of 1-tonne, and unprecedented background
levels, on the order of or less than 1 count per year in the \BBz signal
region. The MAJORANA Collaboration proposes a design based on using high-purity
enriched Ge-76 crystals deployed in ultra-low background electroformed Cu
cryostats and using modern analysis techniques that should be capable of
reaching the required sensitivity while also being scalable to a 1-tonne size.
To demonstrate feasibility, the collaboration plans to construct a prototype
system, the MAJORANA DEMONSTRATOR, consisting of 30 kg of 86% enriched \Ge-76
detectors and 30 kg of natural or isotope-76-depleted Ge detectors. We plan to
deploy and evaluate two different Ge detector technologies, one based on a
p-type configuration and the other on n-type.Comment: paper submitted for the 2008 Carolina International Symposium on
Neutrino Physic
Independent measurement of the total active B8 solar neutrino flux using an array of He3 proportional counters at the Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (νx) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54-0.31+0.33(stat)-0.34+0.36(syst)×106  cm-2 s-1, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Δm2=7.59-0.21+0.19×10-5  eV2 and θ=34.4-1.2+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO’s previous results
Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set
This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees. © 2013 American Physical Society
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