MIMAC: A micro-tpc matrix for dark matter directional detection
D. Santos, J. Billard, G. Bosson, J. L. Bouly, O. Bourrion, C. Fourel, O. Guillaudin, J. Lamblin, J. F. Muraz, F. Mayet, J. P. Richer, Q. Riffard, E. Ferrer, I.… 展开作者
D. Santos, J. Billard, G. Bosson, J. L. Bouly, O. Bourrion, C. Fourel, O. Guillaudin, J. Lamblin, J. F. Muraz, F. Mayet, J. P. Richer, Q. Riffard, E. Ferrer, I. Giomataris, F. J. Iguaz, L. Lebreton, D. Maire
备注：
Proceedings of the 6th Symposium on Large TPCs for low energy rare event detection, Paris, December 2012
暗物质定向探测开辟了一个新的领域，在宇宙学带来的可能性，以建立一个地图的核反冲，将能够探索银河系的暗物质晕，使访问这种物质的粒子表征和形状的晕。MIMAC（MIcro-tpc MAGNETIC of Chambers）合作在过去几年中开发了一种原始原型探测器，该探测器基于大型像素化micromegas与专用快速自触发电子器件的直接耦合，显示了新一代定向探测器的可行性。这种搜索策略的发现潜力进行了讨论和说明。2012年6月，第一个双室原型已经安装在Modane地下实验室（LSM），并显示了第一个地下背景事件，增益稳定性和校准。
英文摘要：
The dark matter directional detection opens a new field in cosmology bringing the possibility to build a map of nuclear recoils that would be able to explore the galactic dark matter halo giving access to a particle characterization of such matter and the shape of the halo. The MIMAC (MIcro-tpc MAtrix of Chambers) collaboration has developed in the last years an original prototype detector based on the direct coupling of large pixelized micromegas with a devoted fast self-triggered electronics showing the feasibility of a new generation of directional detectors. The discovery potential of this search strategy is discussed and illustrated. In June 2012, the first bi-chamber prototype has been installed at Modane Underground Laboratory (LSM) and the first underground background events, the gain stability and calibration are shown.
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…
In the frame of direct dark matter search, the fast neutrons producing elastic collisions are the ultimate background. The MIMAC (MIcro-tpc MAtrix Chambers) project has developed a directional detector providing the directional signature to discriminate them based on 3D nuclear tracks reconstruction. The MIMAC team of the LPSC has adapted one MIMAC chamber as a portable fast neutron spectrometer, the Mimac-FastN detector, having a very large neutron energy range (10 keV - 600 MeV) with different gas mixtures and pressures. The present paper shows its main features and functionality and demonst…
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 is the only strategy for the unambiguous identification of galactic Dark Matter (DM) even in the presence of an irreducible background such as beyond the neutrino floor. This approach requires measuring the direction of a DM-induced nuclear recoil in the keV-range. To probe such low energies, directional detectors must operate at high gain where 3D track reconstruction can be distorted by the influence of the numerous ions produced in the avalanches. The article describes the interplay between electrons and ions during signal formation in a Micromegas. It introduces SimuM…
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…
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…
Negative-ion time projection chambers(TPCs) have been studied for low-rate and high-resolution applications such as dark matter search experiments. Recently, a full volume fiducialization in a self-triggering TPC was realized. This innovative technology demonstrated a significant reduction in the background with MWPC-TPCs. We studied negative-ion TPC using the μ-PIC+GEM system and obtained sufficient gas gain with CS$_{2}$gas and SF$_{6}$ gas at low pressures. We expect an improvement in detector sensitivity and angular resolution with better electronics.
3D-Deuteron Track Recoils Produced by Neutron Capture in Hydrogen Measured by MIMAC-35 cm
LPSC, Université Grenoble Alpes, CNRS/IN2P3（格勒诺布尔阿尔卑斯大学粒子物理与核物理实验室）；Centre de Physique des Particules de Marseille, IN2P3/CNRS and Université Aix-Marseille（马赛粒子物理中心）
A negative ion micro time projection chamber (NI$μ$TPC) was developed and its performance studied. An NI$μ$TPC is a novel technology that enables the measurement of absolute $z$ coordinates for self-triggering TPCs. This technology provides full-fiducialization analysis, which is not possible with conventional gaseous TPCs, and is useful for directional dark matter searches in terms of background rejection and the improvement of the angular resolution. The developed NI$μ$TPC prototype had a detection volume of 12.8 $\times$ 25.6 $\times$ 144 mm$^{3}$. The absolute $z$ coordinate was determined…
Low-pressure gaseous TPCs are well suited detectors to correlate the directions of nuclear recoils to the galactic Dark Matter (DM) halo. Indeed, in addition to providing a measure of the energy deposition due to the elastic scattering of a DM particle on a nucleus in the target gas, they allow for the reconstruction of the track of the recoiling nucleus. In order to exclude the background events originating from radioactive decays on the surfaces of the detector materials within the drift volume, efforts are ongoing to precisely localize the track nuclear recoil in the drift volume along the …
The CYGNO project has the goal to use a gaseous TPC with optical readout to detect dark matter and solar neutrinos with low energy threshold and directionality. The CYGNO demonstrator will consist of 1 m 3 volume filled with He:CF 4 gas mixture at atmospheric pressure. Optical readout with high granularity CMOS sensors, combined with fast light detectors, will provide a detailed reconstruction of the event topology. This will allow to discriminate the nuclear recoil signal from the background, mainly represented by low energy electron recoils induced by radioactivity. Thanks to the high recons…
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…
A new method for directional fast neutron detection is proposed based on a neutron time projection chamber (TPC) and position-sensitive plastic scintillation detectors. The detection system can efficiently locate the approximate location of a hot spot with 4π field-of-view using only the neutron TPC. Then, the system generates a high-resolution image of the hot spot using selected coincidence events in the TPC and the scintillation detectors. A prototype was built and tested using a Cf-252 source. An efficiency of 7.1x10-3 was achieved for fast searching. The angular resolution was 7.8° (full …
A neutron time projection chamber can locate the approximate direction of a neutron hot spot with high efficiency and a 4π field of view. The angular resolution can be significantly improved by adding several plastic scintillation detectors and using coincidence events. The specific performances of such a coincidence imaging system are studied based on theoretical calculations and experimental results. The calculated value of the angular resolution is approximately 2° for the current system, which agrees well with the experimental results and sets an upper limit for the angular resolution of t…
Radon gas emanating from materials is of interest in environmental science and also a major concern in rare event non-accelerator particle physics experiments such as dark matter and double beta decay searches, where it is a major source of background. Notable for dark matter experiments is the production of radon progeny recoils (RPRs), the low energy (~100 keV) recoils of radon daughter isotopes, which can mimic the signal expected from WIMP interactions. Presented here are results of measurements of radon emanation from detector materials in the 1 metre cubed DRIFT-II directional dark matte…
A double-phase argon Time Projection Chamber (TPC), with an active mass of 185 g, has been designed and constructed for the Recoil Directionality (ReD) experiment. The aim of the ReD project is to investigate the directional sensitivity of argon-based TPCs via columnar recombination to nuclear recoils in the energy range of interest (20-200 keV$_{nr}$) for direct dark matter searches. The key novel feature of the ReD TPC is a readout system based on cryogenic Silicon Photomultipliers, which are employed and operated continuously for the first time in an argon TPC. Over the course of six months…
Gaseous time projection chambers (TPCs) with high readout segmentation are capable of reconstructing detailed 3D ionization distributions of nuclear recoils resulting from elastic neutron scattering. Using a system of six compact TPCs with pixel ASIC readout, filled with a 70:30 mixture of He:CO$_2$ gas, we analyze the first directional measurements of beam-induced neutron backgrounds in the tunnel regions surrounding the Belle II detector at the SuperKEKB $e^+e^-$ collider. With the use of 3D recoil tracking, we show that these TPCs are capable of maintaining nearly $100\%$ nuclear recoil pur…
Studies of micro time projection chambers using negative ion gas (NI$μ$TPC) are conducted especially for direction-sensitive dark matter searches. A NI$μ$TPC enables to measure the absolute position in the drift direction for self-triggering TPCs. This study provides a development of a NI$μ$TPC using a micro pixel chamber ($μ$-PIC) with dedicated readout electronics, and an evaluation of the capability of three-dimensional absolute position reconstruction of nuclear recoil using a neutron source. The absolute track position was reconstructed throughout the drift volume with an efficiency of 70…
Several directional techniques have been proposed for a directional detection of Dark matter, among others anisotropic crystal detectors, nuclear emulsion plates, and low-pressure gaseous TPCs. The key point is to get access to the initial direction of the nucleus recoiling due to the elastic scattering by a WIMP. In this article, we aim at estimating, for each method, how the information of the recoil track initial direction is preserved in different detector materials. We use the SRIM simulation code to emulate the motion of the first recoiling nucleus in each material. We propose the use of…
We report on the recent development of a versatile analog front-end compatible with a negative-ion $μ$-TPC for a directional dark matter search as well as a dual-phase, next-generation $\mathcal{O}$(10~kt) liquid argon TPC to study neutrino oscillations, nucleon decay, and astrophysical neutrinos. Although the operating conditions for negative-ion and liquid argon TPCs are quite different (room temperature \textit{vs.} $\sim$88~K operation, respectively), the readout electronics requirements are similar. Both require a wide-dynamic range up to 1600 fC, and less than 2000--5000 e$^-$ noise for …
We report on the design, production, and performance of compact 40-cm$^3$ Time Projection Chambers (TPCs) that detect fast neutrons by measuring the three-dimensional (3D) ionization distribution of nuclear recoils in $^4$He:CO$_2$ gas at atmospheric pressure. We use these detectors to characterize the fast-neutron flux inside the Belle II detector at the SuperKEKB electron-positron collider in Tsukuba, Japan, where the primary design constraint is a small form factor. We find that the TPCs meet or exceed all design specifications, and are capable of measuring the 3D surface shape and charge d…
The aim of the CYGNO project is the construction and operation of a 1~m$^3$ gas TPC for directional dark matter searches and coherent neutrino scattering measurements, as a prototype toward the 100-1000~m$^3$ (0.15-1.5 tons) CYGNUS network of underground experiments. In such a TPC, electrons produced by dark-matter- or neutrino-induced nuclear recoils will drift toward and will be multiplied by a three-layer GEM structure, and the light produced in the avalanche processes will be readout by a sCMOS camera, providing a 2D image of the event with a resolution of a few hundred micrometers. Photom…
The design of the project named CYGNO is presented. CYGNO is a new proposal supported by INFN, the Italian National Institute for Nuclear Physics, within CYGNUs proto-collaboration (CYGNUS-TPC) that aims to realize a distributed observatory in underground laboratories for directional Dark Matter (DM) search and the identification of the coherent neutrino scattering (CNS) from the Sun. CYGNO is one of the first prototypes in the road map to 100-1000 m^3 of CYGNUs and will be located at the National Laboratory of Gran Sasso (LNGS), in Italy, aiming to make significant advances in the technology …
Now that conventional weakly interacting massive particle (WIMP) dark matter searches are approaching the neutrino floor, there has been a resurgence of interest in detectors with sensitivity to nuclear recoil directions. A large-scale directional detector is attractive in that it would have sensitivity below the neutrino floor, be capable of unambiguously establishing the galactic origin of a purported dark matter signal, and could serve a dual purpose as a neutrino observatory. We present the first detailed analysis of a 1000 m$^3$-scale detector capable of measuring a directional nuclear re…
CYGNO is a project realising a cubic meter demonstrator to study the scalability of the performance of the optical approach for the readout of large-volume, GEM-equipped TPC. This is part of the CYGNUS proto-collaboration which aims at constructing a network of underground observatories for directional Dark Matter search. The combined use of high-granularity sCMOS and fast sensors for reading out the light produced in GEM channels during the multiplication processes was shown to allow on one hand to reconstruct 3D direction of the tracks, offering accurate energy measurements and sensitivity t…
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…
Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled …
Directional detection of nuclear recoils is broadly desirable in nuclear and particle physics. At low recoil energies, this capability may be used to confirm the cosmological origin of a dark matter signal, to penetrate the so-called neutrino floor, or to distinguish between different neutrino sources. Gas Time Projection Chambers (TPCs) can enable directional recoil detection if the readout granularity is sufficiently high, as is the case when micro-pattern gaseous detectors (MPGDs) are utilized. A key challenge in such detectors is identifying and rejecting background electron recoil events …
The Time Projection Chamber (TPC) is an ideal candidate to finely study the charged particle ionization in a gaseous medium. Large volumes TPCs can be read out with a suitable number of channels offering a complete 3D reconstruction of an ultra-relativistic charged particle track, that is the sequence of its energy releases in the TPC gas volume. Moreover, He-based TPCs are very promising to study keV energy particles as nuclear recoils, opening the possibility for directional searches of Dark Matter (DM) and the study of Solar Neutrinos (SN). In this paper, we report the analysis of the data …
We develop and validate a new algorithm called \textit{primary track recovery} (\ptr) that effectively deconvolves known physics and detector effects from nuclear recoil tracks in gas time projection chambers (TPCs) with high-resolution readout. This gives access to the primary track charge, length, and vector direction (helping to resolve the "head-tail" ambiguity). Additionally, \ptr provides a measurement of the transverse and longitudinal diffusion widths, which can be used to determine the absolute position of tracks in the drift direction for detector fiducialization. Using simulated hel…
He-CF4-CH4 ternary mixtures as target gas for the CYGNO directional dark matter experiment
University of Coimbra（科英布拉大学）；Universit`a Roma TRE（罗马三所大学）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所；罗马三分所）；Sezione di Roma Tre（格兰萨索科学研究所）；Gran Sasso Science Institute（意大利国家核物理研究所；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；弗拉斯卡蒂国家实验室）；Laboratori Nazionali del Gran Sasso（意大利国家新科技、能源和可持续经济发展局弗拉斯卡蒂研究中心）；Istituto Nazionale di Fisica Nucleare（茹伊斯迪福拉联邦大学）；Laboratori Nazionali di Frascati（罗马大学）；ENEA Centro Ricerche Frascati（意大利国家核物理研究所；罗马分所）；Universidade Federal de Juiz de Fora（罗马大学）；Universit`a di Roma Sapienza（谢菲尔德大学）；Istituto Nazionale di Fisica Nucleare；Sezione di Roma；Sapienza Universit`a di Roma；University of Sheffield
The CYGNO experiment: a gaseous TPC with optical readout for rare events searches
University of Coimbra（科英布拉大学）；Gran Sasso Science Institute（格兰萨索科学研究所）；Laboratori Nazionali del Gran Sasso（格兰萨索国家实验室）；Laboratori Nazionali di Frascati（弗拉斯卡蒂国家实验室）；University of Sheffield（谢菲尔德大学）
Gas Gains Over 10$^4$ and Optimisation using $^{55}$Fe X-rays in Low Pressure SF$_6$ with a Novel Multi-Mesh ThGEM for Directional Dark Matter Searches
High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu…
