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

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

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

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

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

MIMAC-He3 : MIcro-tpc MAtrix of Chambers of He3

The project of a micro-TPC matrix of chambers of He3 for direct detection of non-baryonic dark matter is outlined. The privileged properties of He3 are highlighted. The double detection (ionization - projection of tracks) will assure the electron-recoil discrimination. The complementarity of MIMAC-He3 for supersymmetric dark matter search with respect to other experiments is illustrated. The modular character of the detector allows to have different gases to get A-dependence. The pressure degreee of freedom gives the possibility to work at high and low pressure. The low pressure regime gives the possibility to get the directionality of the tracks. The first measurements of ionization at very few keVs for He3 in He4 gas are described

Mirage: a new iterative Map-Making code for CMB experiments

A major goal of CMB experiments is to obtain highly sensitive CMB maps in order to extract Spherical Harmonic Power Spectrum (SHPS) and cosmological parameters with unprecedented accuracy. We present a new map-making code (Mirage), based on a two-phase iterative algorithm, involving low frequency drift treatment, Butterworth high-pass filtering and conjugate gradient method. This work was strongly motivated by Archeops CMB experiment data analysis. We believe that Archeops was a good test bench for the future Planck Surveyor data analysis, and Mirage was designed in order to be used for Planck data processing with minimal work. A strong feature of Mirage is that it handles experimental problems in data, such as holes in data stream, bright sources, and galaxy side effects, without jeopardising speed. The other advantage is its processing speed, allowing to run Monte Carlo simulations of Archeops data processing on a single processor workstation overnight. Algorithms are explained. Systematic effects on SHPS are investigated on various simulated data, including typical Archeops observational systematics. This code is available at adress http://www-dapnia.cea.fr/Telechargement/ Preprint with full resolution figures is available at http://www-dapnia.cea.fr/Doc/Publications/Archives/dapnia-03-378.pdfComment: 11 pages, accepted in Astron. and Astrophysisc

Extracting constraints from direct detection searches of supersymmetric dark matter in the light of null results from the LHC in the squark sector

The comparison of the results of direct detection of Dark Matter, obtained with various target nuclei, requires model-dependent, or even arbitrary, assumptions. Indeed, to draw conclusions either the spin-dependent (SD) or the spin-independent (SI) interaction has to be neglected. In the light of the null results from supersymmetry searches at the LHC, the squark sector is pushed to high masses. We show that for a squark sector at the TeV scale, the framework used to extract contraints from direct detection searches can be redefined as the number of free parameters is reduced. Moreover, the correlation observed between SI and SD proton cross sections constitutes a key issue for the development of the next generation of Dark Matter detectors.Comment: Figure 3 has been updated. Conclusions unchange