333 research outputs found
The MAJORANA 76Ge neutrino less double-beta decay project: A brief update
At present, MAJORANA is a research and development (R&D) project to
investigate the feasibility and cost of constructing and operating a one ton
decay experiment with ~1000 kg of Ge detectors fabricated from germanium
enriched to 86% in . The study will include three separate cryostats with
various types of detectors: un-segmented, un-segmented point-contact, minimally
segmented, and highly segmented. One cryostat will contain at least 30 kg of
enriched (preferably point-contact) detectors. The performance of the cryostats
and detectors as well as background levels will be investigated. The goal of
the demonstrator project is to reach a discovery sensitivity of ~ 1026 y.Comment: 3 pages, no figure
Ge Detectors and : The Search for Double Beta Decay with Germanium Detectors: Past, Present and Future
High Purity Germanium Detectors have excellent energy resolution; the best
among the technologies used in double beta decay. Since neutrino-less double
beta decay hinges on the search for a rare peak upon a background continuum,
this strength has enabled the technology to consistently provide leading
results. The Ge crystals at the heart of these experiments are very pure; they
have no measurable U or Th contamination. The added efforts to reduce the
background associated with electronics, cryogenic cooling, and shielding have
been very successful, leading to the longevity of productivity. The first
experiment published in 1967 by the Milan group of Fiorini, established the
benchmark half-life limit yr. More recently, the \MJ\ and
GERDA collaborations have developed new detector technologies that optimize the
pulse waveform analysis. As a result, the GERDA collaboration refuted the claim
of observation with a revolutionary approach to shielding by immersing the
detectors directly in radio-pure liquid argon. In 2018, the \MJ\ collaboration,
using a classic vacuum cryostat and high-Z shielding, achieved a background
level near that of GERDA by developing very pure materials for use nearby the
detectors. Together, GERDA and \MJ\ have provided limits approaching
yr. In this article, we elaborate on the historical use of Ge detectors for
double beta decay addressing the strengths and weaknesses. We also summarize
the status and future as many \MJ\ and GERDA collaborators have joined with
scientists from other efforts to give birth to the LEGEND collaboration. LEGEND
will exploit the best features of both experiments to extend the half-life
limit beyond yr with a ton-scale experiment.Comment: Invited submission to Frontiers in Physic
Calorimeter R&D for the SuperNEMO Double Beta Decay Experiment
SuperNEMO is a next-generation double beta decay experiment based on the
successful tracking plus calorimetry design approach of the NEMO3 experiment
currently running in the Laboratoire Souterrain de Modane (LSM). SuperNEMO can
study a range of isotopes, the baseline isotopes are 82Se and possibly 150Nd.
The total isotope mass will be 100-200 kg. A sensitivity to neutrinoless double
beta decay half-life greater than 10e26 years can be reached which gives access
to Majorana neutrino masses of 50-100 meV. One of the main challenges of the
SuperNEMO R&D is the development of the calorimeter with an unprecedented
energy resolution of 4% FWHM at 3 MeV (Qbb value of 82Se).Comment: Presented at 13th International Conference on Calorimetry in High
Energy Physics (CALOR08), Pavia, Italy, 26-30 May 200
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