729 research outputs found
Energy resolution of alpha particles in a microbulk Micromegas detector at high pressure Argon and Xenon mixtures
The latest Micromesh Gas Amplification Structures (Micromegas) are achieving
outstanding energy resolution for low energy photons, with values as low as 11%
FWHM for the 5.9 keV line of Fe in argon/isobutane mixtures at
atmospheric pressure. At higher energies (MeV scale), these measurements are
more complicated due to the difficulty in confining the events in the chamber,
although there is no fundamental reason why resolutions of 1% FWHM or below
could not be reached. There is much motivation to demonstrate experimentally
this fact in Xe mixtures due to the possible application of Micromegas readouts
to the Double Beta Decay search of Xe, or in other experiments needing
calorimetry and topology in the same detector. In this paper, we report on
systematic measurements of energy resolution with state-of-the-art Micromegas
using a 5.5 MeV alpha source in high pressure Ar/isobutane mixtures. Values as
low as 1.8% FWHM have been obtained, with possible evidence that better
resolutions are achievable. Similar measurements in Xe, of which a preliminary
result is also shown here, are under progress.Comment: 16 pages, 19 figures, version after referees comments. Accepted for
publication in Nuclear Instruments and Methods
Supernova Detection via a Network of Neutral Current Spherical TPC's
The coherent contribution of all neutrons in neutrino nucleus scattering due
to the neutral current offers a realistic prospect of detecting supernova
neutrinos. For a typical supernova at 10 kpc, about 1000 events are expected
using a spherical gaseous detector of radius 4 m and employing Xe gas at a
pressure of 10 Atm. We propose a world wide network of several such simple,
stable and low cost supernova detectors with a running time of a few centuries.Comment: 7 pages, 2 figures. Talk presented at the International Symposium on
Origin of Matter and Evolution of Galaxies (OMEG05)- New Horizon of Nuclear
Astrophysics and Cosmology November 8-11, 2005, University of Tokyo, Tokyo,
Japa
The TESLA Time Projection Chamber
A large Time Projection Chamber is proposed as part of the tracking system
for a detector at the TESLA electron positron linear collider. Different
ongoing R&D studies are reviewed, stressing progress made on a new type readout
technique based on Micro-Pattern Gas Detectors.Comment: 5 pages, 8 figures; Proceeding for the topical Seminar on Innovative
Particle and Radiation Detectors Siena, 21-24 October 2002; to appear in
Nucl.Phys. B (Proceedings Supplement
Nostos - Spherical TPCs
A new concept, the spherical TPC, presents unique advantages when low energy
neutrinos are to be detected. Some of the applications are: a) observation of
the e oscillation when emitted by a tritium source ( = 14 keV) in a 10 m
radius sphere. This project, baptized NOSTOS, intends to give the mixing angle
13, the Weinberg angle and a much lower limit (< 10-12 ?B) of the neutrino
magnetic moment, b) an array of small (radius 2-4 m), cheap spheres scattered
around the world would be perfect to monitor extragalactic supernovae, c)
detect the spectrum of low energy (pp - 7Be) solar neutrinos.Comment: XIII International Symposium on Very High Energy Cosmic Ray
Interactions at the NESTOR Institute - Pylos, Grece, 6-12 Septembre 200
Micromegas in a Bulk
In this paper we present a novel way to manufacture the bulk Micromegas
detector. A simple process based on the PCB (Printed Circuit Board) technology
is employed to produce the entire sensitive detector. Such fabrication process
could be extended to very large area detectors made by the industry. The low
cost fabrication together with the robustness of the electrode materials will
make it extremely attractive for several applications ranging from particle
physics and astrophysics to medicineComment: 6 pages, 4 figure
A Network of Neutral Current Spherical TPC's for Dedicated Supernova Detection
The coherent contribution of all neutrons in neutrino nucleus scattering due
to the neutral current offers a realistic prospect of detecting supernova
neutrinos. As a matter of fact. for a typical supernova at 10 kpc, about 1000
events are expected usinga spherical gaseous detector of radius 4 m
andemploying Xe gas at a pressure of 10 Atm. We propose a world wide network of
several such simple, stable and low cost supernova detectors with a running
time of a few centuries.Comment: 17 LaTex pages, 9 PostScript figure
Low-background applications of MICROMEGAS detector technology
The MICROMEGAS detector concept, generally optimized for use in accelerator
experiments, displays a peculiar combination of features that can be
advantageous in several astroparticle and neutrino physics applications. Their
sub-keV ionization energy threshold, excellent energy and space resolution, and
a simplicity of design that allows the use of radioclean materials in their
construction are some of these characteristics. We envision tackling
experimental challenges such as the measurement of neutral-current
neutrino-nucleus coherent scattering or Weakly Interacting Massive Particle
(WIMP) detectors with directional sensitivity. The large physics potential of a
compact (total volume O(1)m), multi-purpose array of low-background
MICROMEGAS is made evident.Comment: 5 pg, presented at IMAGING-2000, Stockholm, June 2000. To appear in
Nucl. Instr. & Meth. Final version after referees' inpu
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