6,519 research outputs found
Characterization of 30 Ge enriched Broad Energy Ge detectors for GERDA Phase II
The GERmanium Detector Array (GERDA) is a low background experiment located
at the Laboratori Nazionali del Gran Sasso in Italy, which searches for
neutrinoless double beta decay of Ge into Se+2e. GERDA has
been conceived in two phases. Phase II, which started in December 2015,
features several novelties including 30 new Ge detectors. These were
manufactured according to the Broad Energy Germanium (BEGe) detector design
that has a better background discrimination capability and energy resolution
compared to formerly widely-used types. Prior to their installation, the new
BEGe detectors were mounted in vacuum cryostats and characterized in detail in
the HADES underground laboratory in Belgium. This paper describes the
properties and the overall performance of these detectors during operation in
vacuum. The characterization campaign provided not only direct input for GERDA
Phase II data collection and analyses, but also allowed to study detector
phenomena, detector correlations as well as to test the strength of pulse shape
simulation codes.Comment: 29 pages, 18 figure
On the Electric Breakdown in Liquid Argon at Centimeter Scale
We present a study on the dependence of electric breakdown discharge
properties on electrode geometry and the breakdown field in liquid argon near
its boiling point. The measurements were performed with a spherical cathode and
a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of
the time evolution of the breakdown volt-ampere characteristics was performed
for the first time. It revealed a slow streamer development phase in the
discharge. The results of a spectroscopic study of the visible light emission
of the breakdowns complement the measurements. The light emission from the
initial phase of the discharge is attributed to electro-luminescence of liquid
argon following a current of drifting electrons. These results contribute to
set benchmarks for breakdown-safe design of ionization detectors, such as
Liquid Argon Time Projection Chambers (LAr TPC).Comment: Minor revision according to editor report. 17 pages, 15 figures, 2
tables. Turboencabulato
Advanced detectors and signal processing
Continued progress is reported toward development of a silicon on garnet technology which would allow fabrication of advanced detection and signal processing circuits on bubble memories. The first integrated detectors and propagation patterns have been designed and incorporated on a new mask set. In addition, annealing studies on spacer layers are performed. Based on those studies, a new double layer spacer is proposed which should reduce contamination of the silicon originating in the substrate. Finally, the magnetic sensitivity of uncontaminated detectors from the last lot of wafers is measured. The measured sensitivity is lower than anticipated but still higher than present magnetoresistive detectors
Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster
Neutrino physics is nowadays receiving more and more attention as a possible
source of information for the long-standing problem of new physics beyond the
Standard Model. The recent measurement of the mixing angle in the
standard mixing oscillation scenario encourages us to pursue the still missing
results on leptonic CP violation and absolute neutrino masses. However,
puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE
Collaboration has been setup to undertake conclusive experiments to clarify the
muon-neutrino disappearance measurements at small , which will be able to
put severe constraints to models with more than the three-standard neutrinos,
or even to robustly measure the presence of a new kind of neutrino oscillation
for the first time. To this aim the use of the current FNAL-Booster neutrino
beam for a Short-Baseline experiment has been carefully evaluated. This
proposal refers to the use of magnetic spectrometers at two different sites,
Near and Far. Their positions have been extensively studied, together with the
possible performances of two OPERA-like spectrometers. The proposal is
constrained by availability of existing hardware and a time-schedule compatible
with the CERN project for a new more performant neutrino beam, which will
nicely extend the physics results achievable at the Booster. The possible FNAL
experiment will allow to clarify the current disappearance tension
with appearance and disappearance at the eV mass scale. Instead, a new
CERN neutrino beam would allow a further span in the parameter space together
with a refined control of systematics and, more relevant, the measurement of
the antineutrino sector, by upgrading the spectrometer with detectors currently
under R&D study.Comment: 76 pages, 52 figure
A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam
A Short-Baseline Neutrino (SBN) physics program of three LAr-TPC detectors
located along the Booster Neutrino Beam (BNB) at Fermilab is presented. This
new SBN Program will deliver a rich and compelling physics opportunity,
including the ability to resolve a class of experimental anomalies in neutrino
physics and to perform the most sensitive search to date for sterile neutrinos
at the eV mass-scale through both appearance and disappearance oscillation
channels. Using data sets of 6.6e20 protons on target (P.O.T.) in the LAr1-ND
and ICARUS T600 detectors plus 13.2e20 P.O.T. in the MicroBooNE detector, we
estimate that a search for muon neutrino to electron neutrino appearance can be
performed with ~5 sigma sensitivity for the LSND allowed (99% C.L.) parameter
region. In this proposal for the SBN Program, we describe the physics analysis,
the conceptual design of the LAr1-ND detector, the design and refurbishment of
the T600 detector, the necessary infrastructure required to execute the
program, and a possible reconfiguration of the BNB target and horn system to
improve its performance for oscillation searches.Comment: 209 pages, 129 figure
High Energy Neutrino Astronomy: WIN 99
Although high energy neutrino astronomy is a multidisciplinary science, gamma
ray bursts have become the theoretical focus since recent astronomical
observations revealed their potential as cosmic particle accelerators. This
spotlight is shared with investigations of the potential of high energy
telescopes to observe oscillating atmospheric neutrinos. The Superkamiokande
results have boosted atmospheric neutrinos from a calibration tool and a
background for doing astronomy, to an opportunity to confirm the evidence for
neutrino mass. Nevertheless, the highlights are mostly on the experimental
front with the completion of the first-generation Baikal and AMANDA detectors.
Neutrino signals from the Lake Baikal detector bode well for the flurry of
activities in the Mediterranean. The completed AMANDA telescope announced first
light, neutrinos actually, at this meeting.Comment: 14 pages, Latex2.09, uses sprocl.sty and epsf.sty, 5 postscript
figures. Talk presented at the 17th International Workshop on Weak
Interactions and Neutrinos, Cape Town, South Africa, January 199
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