2,181 research outputs found
Performance Results of the AMS-01 Aerogel Threshold Cherenkov
The Alpha Magnetic Spectrometer (AMS) was flown in june 1998 on board of the
space shuttle Discovery (flight STS-91) at an altitude ranging between 320 and
390 km. This preliminary version of AMS included an Aerogel Threshold Cherenkov
detector (ATC) to separate antiprotons from electron background, for momenta
less than 3.5 GeV/c. In this paper, the design and physical principles of ATC
will be discussed briefly, then the performance results of the ATC will be
presented.Comment: 3 pages, 3 figures, to be published in the proceedings of the XIth
Rencontres de Blois (Frontiers of Matter), held in Blois (France), June
27-July 3, 199
MIMAC : Detection of low energy recoils for Dark Matter search
The MIMAC project is based on a matrix of Micro Time Projection Chambers
(micro-TPC) for Dark Matter search, filled with He3 or CF4 and using ionization
and tracks. The first measurement of the energy resolution of this micro-TPC is
presented as well as its low thresholdComment: Dark Energy and Dark Matter conference, Lyon : France (2008
A review on the discovery reach of Dark Matter directional detection
Directional detection of galactic Dark Matter offers a unique opportunity to
identify Weakly Interacting Massive Particle (WIMP) events as such. Depending
on the unknown WIMP-nucleon cross section, directional detection may be used to
: exclude Dark Matter, discover galactic Dark Matter with a high significance
or constrain WIMP and halo properties. We review the discovery reach of Dark
Matter directional detection.Comment: Proceedings of the 4th international conference on Directional
Detection of Dark Matter (CYGNUS 2013), 10-12 June 2013, Toyama, Japa
Supersymmetric dark matter search via spin-dependent interaction with He3
The potentialities of MIMAC-He3, a MIcro-tpc MAtrix of Chambers of Helium 3,
for supersymmetric dark matter search are discussed within the framework of
effective MSSM models without gaugino mass unification at the GUT scale. A
phenomenological study has been done to investigate the sensitivity of the
MIMAC-He3 detector to neutralinos (m > 6 GeV/c2) via spin-dependent interaction
with He3 as well as its complementarity to direct and indirect detection
experiments. Comparison with other direct dark matter searches will be
presented in a WIMP model-independent framework.Comment: 13 pages, 5 figure
Identification of Dark Matter with directional detection
Directional detection is a promising search strategy to discover galactic
Dark Matter. Taking advantage on the rotation of the Solar system around the
Galactic center through the Dark Matter halo, it allows to show a direction
dependence of WIMP events. Data of directional detectors are composed of energy
and a 3D track for each recoiling nuclei. Here, we present a Bayesian analysis
method dedicated to data from upcoming directional detectors. However, we focus
only on the angular part of the event distribution, arguing that the energy
part of the background distribution is unknown. Two different cases are
considered: a positive or a null detection of Dark Matter. In the first
scenario, we will present a map-based likelihood method allowing to recover the
main incoming direction of the signal and its significance, thus proving its
Galactic origin. In the second scenario, a new statistical method is proposed.
It is based on an extended likelihood in order to set robust and competitive
exclusion limits. This method has been compared to two other methods and has
been shown to be optimal in any detector configurations. Eventually, prospects
for the MIMAC project are presented in the case of a 10 kg CF4 detector with an
exposition time of 3 years.Comment: Proceeding of the 8th International Workshop on the Identification of
Dark Matter (IDM 2010), July 2010, Montpellier, France. To appear in
Proceedings of Science (PoS
Directional detection of galactic dark matter
Directional detection is a promising Dark Matter search strategy. Taking
advantage on the rotation of the Solar system around the galactic center
through the Dark Matter halo, it allows to show a direction dependence of WIMP
events that may be a powerful tool to identify genuine WIMP events as such.
Directional detection strategy requires the simultaneous measurement of the
energy and the 3D track of low energy recoils, which is a common challenge for
all current projects of directional detectors.Comment: Proceedings of UCLA Dark Matter 2012, 10th Symposium on Sources and
Detection of Dark Matter and Dark Energy in the Universe, Marina del Rey
Marriott, CA, USA, February 22-24, 201
Full PIC simulation of a first ACHIP experiment @ SINBAD
In laser illuminated dielectric accelerators (DLA) high acceleration
gradients can be achieved due to high damage thresholds of the materials at
optical frequencies. This is a necessity for developing more compact particle
accelerator technologies. The Accelerator on a CHip International Program
(ACHIP) funded by the Gordon and Betty Moore Foundation is researching such
devices. DESY Hamburg is part of the collaboration. The dedicated accelerator
research facility SINBAD is particularly well suited for DLA experiments at
relativistic electron energies. High quality beams and short bunch lengths are
anticipated from the ARES linac which is currently under construction at
SINBAD. The aim of the experiment is the injection of a short electron bunch
from the ARES linac into a DLA. In this study the results of one of the first
possible experiments at the facility are estimated via a combination of
particle-in-cell (PIC) and tracking simulations. ASTRA is used to simulate an
electron bunch from the ARES linac at a suitable working point. The dielectric
part of the setup will be simulated using the PIC code from CST Particle Studio
incorporating the retrieved bunch from the ASTRA simulation. The energy spectra
of the electron bunches are calculated as would be measured from a spectrometer
dipole with and without the laser fields
An analysis method for time ordered data processing of Dark Matter experiments
The analysis of the time ordered data of Dark Matter experiments is becoming
more and more challenging with the increase of sensitivity in the ongoing and
forthcoming projects. Combined with the well-known level of background events,
this leads to a rather high level of pile-up in the data. Ionization,
scintillation as well as bolometric signals present common features in their
acquisition timeline: low frequency baselines, random gaussian noise, parasitic
noise and signal characterized by well-defined peaks. In particular, in the
case of long-lasting signals such as bolometric ones, the pile-up of events may
lead to an inaccurate reconstruction of the physical signal (misidentification
as well as fake events). We present a general method to detect and extract
signals in noisy data with a high pile-up rate and qe show that events from few
keV to hundreds of keV can be reconstructed in time ordered data presenting a
high pile-up rate. This method is based on an iterative detection and fitting
procedure combined with prior wavelet-based denoising of the data and baseline
subtraction. {We have tested this method on simulated data of the MACHe3
prototype experiment and shown that the iterative fitting procedure allows us
to recover the lowest energy events, of the order of a few keV, in the presence
of background signals from a few to hundreds of keV. Finally we applied this
method to the recent MACHe3 data to successfully measure the spectrum of
conversion electrons from Co57 source and also the spectrum of the background
cosmic muons
Search for Supersymmetric Dark Matter with Superfluid He3 (MACHe3)
MACHe3 (MAtrix of Cells of superfluid He3) is a project of a new detector for
direct Dark Matter search, using superfluid He3 as a sensitive medium. This
paper presents a phenomenological study done with the DarkSUSY code, in order
to investigate the discovery potential of this project of detector, as well as
its complementarity with existing and planned devices.Comment: 15 pages, 5 figures, submitted to Phys. Letters B, minor changes in
the tex
Coagulation revisited: special focus on prothrombotic states and anticoagulation
No Abstract. Southern African Journal of Anaesthesia and Analgesia Vol. 12(1) 2006: 2
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