A complete dedicated electronics, from front-end to back-end, was developed to instrument a MIMAC prototype. A front end ASIC able to monitor 64 strips of pixels and to provide their individual "Time Over Threshold" information has been designed. An associated acquisition electronics and a real time track reconstruction software have been developed to monitor a 512 channel prototype. This auto-triggered electronic uses embedded processing to reduce the data transfer to its useful part only, i.e. decoded coordinates of hit tracks and corresponding energy measurements. The electronic designs, acquisition software and the results obtained are presented.
Directional detection is a promising search strategy to discover galactic Dark Matter. We present a Bayesian analysis framework dedicated to Dark Matter phenomenology using directional detection. The interest of directional detection as a powerful tool to set exclusion limits, to authentify a Dark Matter detection or to constrain the Dark Matter properties, both from particle physics and galactic halo physics, will be demonstrated. However, such results need highly accurate track reconstruction which should be reachable by the MIMAC detector using a dedicated readout combined with a likelihood…
Directional detection of galactic Dark Matter requires 3D reconstruction of low energy nuclear recoils tracks. A dedicated acquisition electronics with auto triggering feature and a real time track reconstruction software have been developed within the framework of the MIMAC project of detector. This auto-triggered acquisition electronic uses embedded processing to reduce data transfer to its useful part only, i.e. decoded coordinates of hit tracks and corresponding energy measurements. An acquisition software with on-line monitoring and 3D track reconstruction is also presented.
A front end ASIC has been designed to equip the μTPC prototype developed for the MIMAC project, which requires 3D reconstruction of low energy particle tracks in order to perform directional detection of galactic Dark Matter. Each ASIC is able to monitor 64 strips of pixels and provides the "Time Over Threshold" information for each of those. These 64 digital informations, sampled at a rate of 50 MHz, can be transferred at 400MHz by eight LVDS serial links. Eight ASIC were validated on a 2x256 strips of pixels prototype.
Directional detection of non-baryonic Dark Matter is a promising search strategy for discriminating genuine WIMP events from background ones. However, carrying out such a strategy requires both a precise measurement of the energy down to a few keV and 3D reconstruction of tracks down to a few mm. To achieve this goal, the MIMAC project has been developed: it is based on a gaseous micro-TPC matrix, filled with 3He, CF4 and/or C4H10. Firsts results of low energy nuclei recoils obtained with a low energy neutron field are presented.
Directional detection of Dark Matter is a promising search strategy. However, to perform such kind of detection, the recoiling tracks have to be accurately reconstructed: direction, sense and position in the detector volume. In order to optimize the track reconstruction and to fully exploit the data from the MIMAC detector, we developed a likelihood method dedicated to the track reconstruction. This likelihood approach requires a full simulation of track measurements with MIMAC in order to compare real tracks to simulated ones. Finally, we found that the MIMAC detector should have the required…
A front end ASIC (BiCMOS-SiGe 0.35 \mum) has been developed within the framework of the MIMAC detector project, which aims at directional detection of non-baryonic Dark Matter. This search strategy requires 3D reconstruction of low energy (a few keV) tracks with a gaseous \muTPC. The development of this front end ASIC is a key point of the project, allowing the 3D track reconstruction. Each ASIC monitors 16 strips of pixels with charge preamplifiers and their time over threshold is provided in real time by current discriminators via two serializing LVDS links working at 320 MHz. The charge is …
MiMac is a project of micro-TPC matrix of gaseous (He3, CF4) chambers for direct detection of non-baryonic dark matter. Measurement of both track and ionization energy will allow the electron-recoil discrimination, while access to the directionnality of the tracks will open a unique way to distinguish a geniune WIMP signal from any background. First reconstructed tracks of 5.9 keV electrons are presented as a proof of concept.
Directional detection of non-baryonic Dark Matter is a promising search strategy for discriminating WIMP events from background. However, this strategy requires both a precise measurement of the energy down to a few keV and 3D reconstruction of tracks down to a few mm. To achieve this goal, the MIMAC project has been developed. It is based on a gaseous micro-TPC matrix, filled with 3He, CF4 and/or C4H10. The first results on low energy nuclear recoils (1H and 19F) obtained with a low mono-energetic neutron field are presented. The discovery potential of this search strategy is discussed and il…
Directional detection of non-baryonic DarkMatter is a promising search strategy for discriminating WIMP events from background ones. This strategy requires both a measurement of the recoil energy down to a few keV and 3D reconstruction of tracks down to a few mm. The MIMAC project, based on a micro-TPC matrix, filled with CF4 and CHF3 is being developed. The first results of a chamber prototype of this matrix, on low energy nuclear recoils (1H and 19F) obtained with mono-energetic neutron fields are presented. The discovery potential of this search strategy is illustrated by a realistic case a…
We have developed a micro-tpc using a pixelized bulk micromegas coupled to dedicated acquisition electronics as a read-out allowing to reconstruct the three dimensional track of a few keV recoils. The prototype has been tested with the Amande facility at the IRSN-Cadarache providing monochromatic neutrons. The first results concerning discrimination of a few keV electrons and proton recoils are presented.
Directional detection is a promising direct Dark Matter (DM) search strategy. The angular distribution of the nuclear recoil tracks from WIMP events should present an anisotropy in galactic coordinates. This strategy requires both a measurement of the recoil energy with a threshold of about 5 keV and 3D recoil tracks down to few millimeters. The MIMAC project, based on a \textmu-TPC matrix, with $CF_4$ and $CHF_3$, is being developed. In June 2012, a bi-chamber prototype was installed at the LSM (Laboratoire Souterrain de Modane). A preliminary analysis of the first four months data taking all…
The MIMAC experiment is a $μ$-TPC matrix project for directional dark matter search. Directional detection is a strategy based on the measurement of the WIMP flux anisotropy due to the solar system motion with respect to the dark matter halo. The main purpose of MIMAC project is the measurement of the energy and the direction of nuclear recoils in 3D produced by elastic scattering of WIMPs. Since June 2012 a bi-chamber prototype is operating at the Modane underground laboratory. In this paper, we report the first ionization energy and 3D track observations of nuclear recoils produced by the ra…
Directional detection of non-baryonic Dark Matter requires 3D reconstruction of low energy nuclear recoils tracks. A gaseous micro-TPC matrix, filled with either 3He, CF4 or C4H10 has been developed within the MIMAC project. A dedicated acquisition electronics and a real time track reconstruction software have been developed to monitor a 512 channel prototype. This autotriggered electronic uses embedded processing to reduce the data transfer to its useful part only, i.e. decoded coordinates of hit tracks and corresponding energy measurements. An acquisition software with on-line monitoring and…
The aim of the MIMAC project is to detect non-baryonic Dark Matter with a directional TPC. The recent Micromegas efforts towards building a large size detector will be described, in particular the characterization measurements of a prototype detector of 10 $\times$ 10 cm$^2$ with a 2 dimensional readout plane. Track reconstruction with alpha particles will be shown.
Weakly Interacting Massive Particles (WIMPs) are one of the most preferred candidate for Dark Matter. WIMPs should interact with the nuclei of detectors. If a robust signal is eventually observed in direct detection experiments, the best signature to confirm its Galactic origin would be the nuclear recoil track direction. The MIMAC collaboration has developed a low pressure gas detector providing both the kinetic energy and three-dimensional track reconstruction of nuclear recoils. In this paper we report the first ever observations of $^{19}$F nuclei tracks in a $5$ cm drift prototype MIMAC d…
MIMAC (MIcro-TPC MAtrix of Chambers) is a directional WIMP Dark Matter detector project. Direct dark matter experiments need a high level of electron/recoil discrimination to search for nuclear recoils produced by WIMP-nucleus elastic scattering. In this paper, we proposed an original method for electron event rejection based on a multivariate analysis applied to experimental data acquired using monochromatic neutron fields. This analysis shows that a $10^5$ rejection power is reachable for electron/recoil discrimination. Moreover, the efficiency was estimated by a Monte-Carlo simulation showi…
Particles weakly interacting with ordinary matter, with an associated mass of the order of an atomic nucleus (WIMPs), are plausible candidates for Dark Matter. The direct detection of an elastic collision of a target nuclei induced by one of these WIMPs has to be discriminated from the signal produced by the neutrons, which leaves the same signal in a detector. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has developed an original prototype detector which combines a large pixelated Micromegas coupled with a fast, self-triggering, electronics. Aspects of the two-chamber module in oper…
Three-dimensional track reconstruction is a key issue for directional Dark Matter detection and it requires a precise knowledge of the electron drift velocity. Magboltz simulations are known to give a good evaluation of this parameter. However, large TPC operated underground on long time scale may be characterized by an effective electron drift velocity that may differ from the value evaluated by simulation. In situ measurement of this key parameter is hence needed as it is a way to avoid bias in the 3D track reconstruction. We present a dedicated method for the measurement of the electron dri…
We investigate the capability of directional detectors to probe neutralino dark matter in the Minimal Supersymmetric Standard Model and the Next-to-Minimal Supersymmetric Standard Model with parameters defined at the weak scale. We show that directional detectors such as the future MIMAC detector will probe spin dependent dark matter scattering on nucleons that are beyond the reach of current spin independent detectors. The complementarity between indirect searches, in particular using gamma rays from dwarf spheroidal galaxies, spin dependent and spin independent direct search techniques is em…
Directional detection of Dark Matter is a promising search strategy. However, to perform such detection, a given set of parameters has to be retrieved from the recoiling tracks : direction, sense and position in the detector volume. In order to optimize the track reconstruction and to fully exploit the data of forthcoming directional detectors, we present a likelihood method dedicated to 3D track reconstruction. This new analysis method is applied to the MIMAC detector. It requires a full simulation of track measurements in order to compare real tracks to simulated ones. We conclude that a goo…
Three-dimensional track reconstruction is a key issue for directional Dark Matter detection. It requires a precise knowledge of the electron drift velocity. Magboltz simulations are known to give a good evaluation of this parameter. However, large TPC operated underground on long time scale may be characterized by an effective electron drift velocity that may differ from the value evaluated by simulation. In situ measurement of this key parameter is hence a way to avoid bias in the 3D track reconstruction. We present a dedicated method for the measurement of the electron drift velocity with th…
More target mass is required in current TPC based directional dark matter detectors for improved detector sensitivity. This can be achieved by scaling up the detector volumes, but this results in the need for more analogue signal channels. A possible solution to reducing the overall cost of the charge readout electronics is to multiplex the signal readout channels. Here, we present a multiplexer system in expanded mode based on LMH6574 chips produced by Texas Instruments, originally designed for video processing. The setup has a capability of reducing the number of readouts in such TPC detecto…
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 differ…
Sensitivities of current directional dark matter search detectors using gas time projection chambers are now constrained by target mass. A ton-scale gas TPC detector will require large charge readout areas. We present a first demonstration of a novel ThGEM-Multiwire hybrid charge readout technology which combines the robust nature and high gas gain of Thick Gaseous Electron Multipliers with lower capacitive noise of a one-plane multiwire charge readout in SF$_6$ target gas. Measurements performed with this hybrid detector show an ion drift velocity of $139~\pm~12~\text{ms}^{-1}$ in a reduced d…
Over the past decades, several ideas and technologies have been developed to directly detect WIMP from the galactic halo. All these detection strategies share the common goal of discriminating a WIMP signal from the residual backgrounds. By directly detecting WIMPs, one can measure some or all of the observables associated to each nuclear recoil candidates, such as their energy and direction. In this study, we compare and examine the discovery potentials of each readout strategies from counting only (bubble chambers) to directional detectors (Time Projection Chambers) with 1d-, 2d-, and 3d-sen…
The measurement of the direction of WIMP-induced nuclear recoils is a compelling but technologically challenging strategy to provide an unambiguous signature of the detection of Galactic dark matter. Most directional detectors aim to reconstruct the dark-matter-induced nuclear recoil tracks, either in gas or solid targets. The main challenge with directional detection is the need for high spatial resolution over large volumes, which puts strong requirements on the readout technologies. In this paper we review the various detector readout technologies used by directional detectors. In particula…
A Large-Area Optical Time Projection Chamber for Hard X-ray Polarimetry with Directional Imaging of Low-Energy Electron Recoils
Gran Sasso Science Institute（格兰萨索科学研究所）；INFN Laboratori Nazionali del Gran Sasso（意大利国家核物理研究所大萨索国家实验室）；INFN Laboratori Nazionali di Frascati（意大利国家核物理研究所弗拉斯卡蒂国家实验室）；IAPS - INAF Istituto di Astrofisica e Planetologia Spaziali（空间天体物理学和行星学研究所-意大利国家天体物理研究所）
In this study, we are doing R&D for directional dark matter search with nuclear emulsion. First of all, higher resolution nuclear emulsion with fine silver halide crystals was developed in the production facility of emulsion at Nagoya university, and we confirmed that it can detect the expected nuclear recoil tracks. The readout of submicron tracks was required the new technology. We developed the expansion technique, and could readout the signal by shape analysis with optical microscopy. The two dimensional angular resolution is 36 degrees at the original track length of range from 150nm to 2…
Direction-sensitive WIMP dark matter searches may help overcome the challenges faced by direct dark matter detection experiments. In particular, directional detectors should be able to clearly differentiate a dark matter signal from background sources. We are developing a Directional Dark Matter Detector (D$^3$) based on a gas Time Projection Chamber (TPC) using Gas Electron Multipliers (GEMs) for charge amplification and pixel electronics for readout. This approach allows the three-dimensional reconstruction of nuclear recoils in a room-temperature detector with low energy threshold and low n…
The Dark Matter Time Projection Chamber (DMTPC) is a direction-sensitive detector designed to measure the direction of recoiling $^{19}$F and $^{12}$C nuclei in low-pressure CF$_4$ gas using optical and charge readout systems. In this paper, we employ measurements from two DMTPC detectors, with operating pressures of 30-60 torr, to develop and validate a model of the directional response and performance of such detectors as a function of recoil energy. Using our model as a benchmark, we formulate the necessary specifications for a scalable directional detector with sensitivity comparable to th…
We designed a versatile analog front-end chip, called LTARS, for TPC-applications, primarily targeted at dual-phase liquid Ar-TPCs for neutrino experiments and negative-ion $μ$-TPCs for directional dark matter searches. Low-noise performance and wide dynamic range are two requirements for reading out the signals induced on the TPC readout channels. One of the development objectives is to establish the analog processing circuits under low temperature operation, which are designed on function block basis as reusable IPs (Intellectual Properties). The newly developed ASIC was implemented in the S…
Characterization of field cage and cathode for low radioactivity operation with the CYGNO experiment
University of Coimbra（科英布拉大学）；Gran Sasso Science Institute（格兰萨索科学研究所）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所）；Laboratori Nazionali del Gran Sasso（格兰萨索国家实验室）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所）；Laboratori Nazionali di Frascati（弗拉斯卡蒂国家实验室）；University of Sheffield（谢菲尔德大学）；Jagiellonian University, Doctoral School of Exact and Natural Sciences（亚捷隆大学）
