MIMAC MIcro-tpc MAtrix of Chambers A Large TPC for Directional Dark Matter detection Daniel Santos Laboratoire de Physique Subatomique et de Cosmologie (LPSC-Grenoble) (Université Grenoble-Alpes -CNRS/IN2P3)
MIMAC (MIcro-tpc MAtrix of Chambers ) LPSC (Grenoble) : D. Santos, F.Naraghi C.Couturier (post-doc), N. Sauzet - Technical Coordination, Gas circulation and detectors : O. Guillaudin - Electronics : G. Bosson, J. Bouvier, J.L. Bouly, L.Gallin-Martel, F. Rarbi - Data Acquisition: T. Descombes - Mechanical Structure : Ch. Fourel, J. Giraud - COMIMAC (quenching) : J-F. Muraz IRFU (Saclay): P. Colas, E. Ferrer-Ribas, I. Giomataris CCPM (Marseille): J. Busto, D. Fouchez, C. Tao Tsinghua University (Beijing-China): C. Tao, I. Moric, Y. Tao XAO (Xinjiang-China): Chung-Lin Shan Neutron facility (AMANDE) : IRSN (Cadarache): T. Vinchon, B. Tampon (Ph. D.) D. Santos (LPSC Grenoble)
Directional detection: principle D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Directional detection : principle Cygnus <V rot > ~ 220 km/s The signature, the only one (!), able to correlate the events in a detector to the galactic halo !! D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
WIMP signal Solar System’s orbit Z G Galactic Center V WIMP X G b l Y G Galactic coordinates V SS Solar System Dark matter Halo = gaz of WIMPs After collision WIMP signal expected Cygnus Constellation (l = 90°,b = 0°) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
There are many “angles” for nuclear recoils… c) Distribution spatiales des reculs Z W Z G Recoil θ R Y W ϕ R b W Y G l W X W X G Map of recoils in galactic coordinates (HealPix) 10 8 Events with E R = [5,50] keV • Collision isotrope dans le CDM: D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
There are many angles to measure… A lot of information and important events to detect 19 F recoils (E kin = 1-110 keV) 19 F recoils (E kin = 1- 40 keV) Angular distribution in the laboratory (with respect to the neutron direction) Angular distribution in the laboratory Produced by neutrons of 565 keV Produced by neutrons of 200 keV Validated experimentally at Cadarache !! Geant4 simulations ( N. Sauzet, DS. (2016)) The same kind of distributions for C !! D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
100 WIMP evts + 100 Background evts a) Simulation d’une mesure réaliste Méthode de vraisemblance Background Wimp recoils D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Phenomenology: Discovery Proof of discovery: Signal pointing toward the Cygnus constellation Blind likelihood analysis in order to establish the galactic origin of the signal Latitude galactique 100 WIMP + 100 BKG Longitude galactique Signature angulaire Strong correlation with the direction of the Constellation Cygnus even with a large background contamination D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Directional Detection : identification 8 parameters simultaneouly constrained by only one 3D experiment Dark Matter signature Galactic Halo shape Mass – cross section σ x Mass l σ y Cross section b σ z D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Running in an Underground Laboratory
MIMAC: Detection strategy E~ 200 V/cm Drifting properties: V ≈ 20 µ m/ns E~ 30 kV/cm Scheme of a MIMAC µ TPC Evolution of the collected charges on the anode Measurement of the ionization energy: Charge integrator connected to the mesh coupled to a FADC sampled at 50 MHz D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
The MIMAC project A low pressure multi-chamber detector • Energy and 3D Track measurements • Matrix of chambers (correlation) • µ TPC : Micromegas technology • CF 4, CHF 3 , and 1 H : σ (A) dependancy Bi-chamber module 2 x (10.8x 10.8x 25 cm 3 ) • Axial and scalar weak interaction • Directionnal detector Strategy: • Directional direct detection • Energy (Ionization) AND 3D-Track of the recoil nuclei • Prove that the signal “comes from Cygnus ” D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
MIMAC experiment MIMAC-bi-chamber module prototype Light WIMP mass • MIMAC Target : Axial coupling •
3D Tracks: Drift velocity Magboltz Simulation Too fast • New mixed gas MIMAC target : CF 4 + x% CHF 3 (x=30) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
MIMAC readout Dedicated fast electronics (self-triggered) Based on the MIMAC chip (64 channels) 3D - track preamplifier signal + FADC: Energy A [ADC-Channels] 2000 Energy τ 1000 0 1000 2000 Time [ns] [ADC-Channels/ns] µ 10 peak σ r σ l A peak 5 dA dt 0 D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016 0 1000 2000 Time [ns]
Ionization Quenching Factor Measurements at LPSC-Grenoble 19 F ( 3 keV) in CF 4 (50 mbar) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Portable Quenching Facility (COMIMAC) (Electrons and Nuclei of known energies) Electrons of 7 keV In a gas detector the IQF depends strongly on the quality of the gas. The IQF needs to be measured periodically (in-situ) in a long term run experiment. D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Ionization Quenching Factors Simulations and Measurements (LPSC) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Ioniza9on ¡Quenching ¡Factor ¡for ¡Fluorine ¡ ¡ in ¡pure ¡CF4 ¡at ¡50 ¡mbar ¡ ¡ 0,900 ¡ ¡ 0,800 ¡ 0,700 ¡ Fluorine ¡in ¡ CF4 ¡at ¡50 ¡ Quenching ¡Factor ¡ 0,600 ¡ mbar ¡ 0,500 ¡ 0,400 ¡ He ¡in ¡He ¡+ ¡ 5% ¡C4H10 ¡at ¡ 0,300 ¡ 350 ¡mbar ¡ 0,200 ¡ 0,100 ¡ 0,000 ¡ 0 ¡ 10 ¡ 20 ¡ 30 ¡ 40 ¡ 50 ¡ 60 ¡ Recoil ¡Energy ¡(keV) ¡
IQF in 4 He + 5% isobutane for different pressures!! 80 Quenching Factor (%) 70 60 50 40 Pressure : 350 mbar 30 700 mbar 1000 mbar 20 1300 mbar 10 0 0 10 20 30 40 50 Total kinetic Energy (keV) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
MIMAC validation with neutrons Neutron monochromatic field: AMANDE facility at IRSN of Cadarache – Neutrons with a well defined energy from resonances of 7 Li by a (p,n) reaction m n m R 2 E neutron cos 2 θ E Re coil = 4 ( ) m n + m R MIMAC one chamber proto Calibration: 7 Li target 55 Fe (5.9 keV) and 109 Cd (3.1 keV) sources Protons beam D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Electron-recoil Discrimination Electron/recoil discrimination 7 Li (p,n (565 keV)) nuclear reaction Neutrons F , C, H, nuclear recoils Electrons electron integrated rejection
22 observables built using the MIMAC readout … . and more … (Q. Riffard et al. arXiv: 1602.01738 (2016)) Observables With fast neutrons NR + e - Only e - Only e - NR + e -
Neutron kinetic energy distribution Focusing on the “Fluorine Endpoint”: - ionization energies above 50 keV - theta < 0.5 rad max ~ 550 keV IDM2016, 7/21/16
Neutron kinetic energy distribution Focusing on the “Fluorine Endpoint”: - ionization /!\ Extrapolating the energies quenching factor above 50 above the measured keV range - theta < 0.2 rad max ~ 545 keV Method Neutron kinetic energy (mean ± 1 σ ) [keV] “Simple” = Joining barycenters of the extreme 542.8 ± 25.6 timeslices Fit of the centroids 541.3 ± 23.8 Fit of every (x,y,z) coincidence 545.8 ± 23.4 IDM2016, 7/21/16 27 Principal Component Analysis 545.7 ± 23.5
Theta distribution Theta_simple (radians) IDM2016, 7/21/16
MIMAC (bi-chamber module)at Modane Underground Laboratory (France) since June 22 nd 2012. Upgraded in June 2013, and in June 2014. -working at 50 mbar (CF 4 +28% CHF 3 + 2% C 4 H 10 ) - in a permanent circulating mode - Remote controlled and commanded - Calibration control twice per week Many thanks to LSM staff D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
Detector calibration (not at the maximum gain!) Calibration : (once a week) 500 Count Cd Fe X-ray generator producing fluorescence 400 Cu Cr photons from Cd, Fe, Cu foils. 300 Threshold ~ 1 keV 200 Circulation system: Cu 100 Excelent Gain stability in time 0 2 4 6 8 10 12 E ioni a [keV/ADC-Channel] [keV] 14 0.015 Energy 12 [keV] Ch. 1 Cu Cu 10 Ch. 2 0.01 8 Fe Cr 6 0.005 Cd 4 2 0 0 02/07/13 31/08/13 31/10/13 0 100 200 300 400 500 600 D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016 Date ADC Channel
An alpha particle crossing the detector (as an illustration of the MIMAC observables) X-Y (anode) X-Z(t) Y-Z(t) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
A “recoil event” ( ~ 34 keVee) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
A “recoil” event (~ 40 keVee) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
An Electron event (18 keV) D. Santos (LPSC Grenoble) DM-France, Paris, Dec 1st 2016
More recommend