[PPT] - Cryogenic charge and phonon detectors: EDELWEISS-SubGeV J. Billard PowerPoint Presentation

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J. Billard

Institut de Physique Nucléaire de Lyon / CNRS / Université Lyon 1 Light Dark Matter Workshop Chicago, June 3-7, 2019

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Cryogenic charge and phonon detectors: EDELWEISS-SubGeV

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EDELWEISS-SubGeV: Scientific context

TeV GeV MeV keV eV

Absorption Electronic recoil DM-electron scattering Electronic recoil DM-Nucleus scattering Nuclear recoil

Standard WIMP Hidden sector Dark Matter and others

8B neutrinos (~ 6 GeV)

Reactor neutrinos (~ 2.7 GeV)

EDELWEISS-SubGeV program

High Voltage single e/h Low Voltage

Part. ID + Fid

High Voltage single e/h Low Voltage

Part. ID + Fid

Not competitive with noble gases experiments

J. Billard (IPNL)

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1) Scalability to significant payload: 1 kg (30 to 200 g crystals) 2) Heat energy resolution (RMS): 10 eV 3) EM background rejection (LV mode): >103 4) Operation at high voltages (HV mode): 100V

Detector wish list:

Goals 1-to-3 are part of a common effort with the Ricochet collaboration, dedicated to studying CENNS at reactors, in the construction of the CRYOCUBE detector supported by the ERC- CENNS Starting Grant (2019-2024)

EDELWEISS-SubGeV: aiming for a kg-scale payload of 30 to 200g Ge detectors running in two modes:

Low Voltage: Particle ID - ER/NR/‘unknown backgrounds’ - and fiducialization (synergy with Ricochet)
High Voltage: single-e/h sensitivity by operating in a Neganov-Luke mode

EDELWEISS-SubGeV: Detector technology

J. Billard (IPNL)

CRYOCUBE

3x3x3 - 30g crystals

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High impedance sensors (NTD, NbSi TES and electrodes) are highly sensitive to microphonics
Highly efficient cryogenic suspension system designed to host kg-scale payloads:
sub micro-g/sqrt{hz} level over the detector bandwidth (limited by accelerometer sensitivity)
Detectors are now running in optimal conditions, only limited by thermodynamic and electronic noises
R. Maisonobe et al., JINST 2018

Goal #1: Scalability and holding system

J. Billard (IPNL)

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J. Billard (IPNL)

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Major accomplishment: 18 eV energy resolution (RMS) 55 eV energy threshold with a 33.4 g detector (Ge) near perfect stability (~%)

Goal #2: Heat energy resolution 10 eV (rms)

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)
Optimisation of thermal design based on a fully data

driven electro-thermal modeling (D. Misiak et al., in preparation)

Large improvement on heat energy resolution:
20 eV (RMS) on four 33.4 g Ge crystals
50 eV (RMS) on a 200 g Ge crystals
Achieved in above-ground operation (IPNL)
Thanks to enhanced thermal response sensitivity and

improved noise conditions (suspension)

PSD from 137 hours displayed

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J. Billard (IPNL)

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Major accomplishment: 18 eV energy resolution (RMS) 55 eV energy threshold with a 33.4 g detector (Ge) near perfect stability (~%)

Goal #2: Heat energy resolution 10 eV (rms)

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)

FET HEMT

(anticipated)

Limited by FET current noise, switch to HEMT in order to reach 10 eV (RMS) on 33.4 g crystals

Optimisation of thermal design based on a fully data

driven electro-thermal modeling (D. Misiak et al., in preparation)

Large improvement on heat energy resolution:
20 eV (RMS) on four 33.4 g Ge crystals
50 eV (RMS) on a 200 g Ge crystals
Achieved in above-ground operation (IPNL)
Thanks to enhanced thermal response sensitivity and

improved noise conditions (suspension)

PSD from 137 hours displayed

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WIMP Mass [GeV/c

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WIMP-nucleon cross section [cm

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EDELWEISS-Surf (Standard) EDELWEISS-Surf (Migdal) EDELWEISS-III LT CRESST Surface CRESST-II SuperCDMS LT CDMSLite LUX (Standard) LUX (Migdal) XENON1T (Standard) XENON100 LT NEWS-G DarkSide (Standard) XQC CMB Neutrino discovery limit + CRESST-III

DM - Nucleus interaction: first Ge-based limit below 1.2 GeV and best above ground limit down to 600 MeV
Migdal effect: first DM limit down to 45 MeV limited by Earth-Shielding effect (B. Kavanagh, 2017), which becomes

significant > 10-31 cm2 (plans to measure this effect with the EDELWEISS experimental setup)

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)

Goal #2: Heat energy resolution 10 eV (rms)

J. Billard (IPNL)

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WIMP Mass [GeV/c

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WIMP-nucleon cross section [cm

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EDELWEISS-Surf (Standard) EDELWEISS-Surf (Migdal) EDELWEISS-III LT CRESST Surface CRESST-II SuperCDMS LT CDMSLite LUX (Standard) LUX (Migdal) XENON1T (Standard) XENON100 LT NEWS-G DarkSide (Standard) XQC CMB Neutrino discovery limit + CRESST-III

DM - Nucleus interaction: first Ge-based limit below 1.2 GeV and best above ground limit down to 600 MeV
Migdal effect: first DM limit down to 45 MeV limited by Earth-Shielding effect (B. Kavanagh, 2017), which becomes

significant > 10-31 cm2 (plans to measure this effect with the EDELWEISS experimental setup)

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)

Reactor neutrinos 1012 /cm2/s

Goal #2: Heat energy resolution 10 eV (rms)

J. Billard (IPNL)

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100 101 102

Cdetector[pF]

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Resolution [eV]

HEMT 1 HEMT 2 HEMT 3 FET

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As initiated by the CDMS-Berkeley group (arXiv:1611.09712)

we are transitioning to HEMT based preamplifiers.

HEMT have lower intrinsic noise than JFET
Work @ 4/1 K allowing to reduce the stray capacitance
Based on our data driven HEMT model, O(10) eV rms

reachable with ~20 pF total input impedance

HEMT characterizations are ongoing
First HEMT-based preamp to be tested in winter 2019 !
Synergie with the Ricochet-CryoCube collaboration

Goal #3: EM background rejection of O(103)

Goal FET to HEMT

20 eV ionization resolution: HEMT preamplifiers + new electrode design

J. Billard (IPNL)

5 pF 35 pF 100 pF

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Design of new electrode scheme with following specs.:
Low input capacitance (10 to 20 pF)
High surface event rejection efficiency (FID mode)
Large fiducial volume (75%)
Aim at O(103) EM background rejection down to 50 eVnr
Synergie with the Ricochet-CryoCube collaboration

Julien Billard

73Ge L-shell

1.3 keV E l e c t r

n

i c r e c

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l s Nuclear recoils

No ionization

RED30: 28 eV heat, 205 eV ionization (24h)

73Ge M-shell

160 eV Heat energy [keV]

0.1 0.2 0.3 0.4

Ionization energy [keVee]

0.05 − 0.05 0.1 0.15

Vetoed Gammas Betas Lead Neutrons CENNS

Nuclear-recoil equivalent energy [keVnr]

0.05 0.1 0.15 0.2 0.25 0.3 0.35

FET to HEMT

Reactor neutrinos / ~2.7 GeV WIMP

Goal #3: EM background rejection of O(103)

20 eV ionization resolution: HEMT preamplifiers + new electrode design

J. Billard (IPNL)

Potential V in V (left) E Field Norm log10(|E|) (right)

Simulation Ge FID h10d30

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DM search zone 160 eV 1.3 keV 10.4 keV

66 Volt s = 5 eVee

NbSi209 Preliminary

160 eV 1.3 keV 10.4 keV DM search zone

RED30

70 Volt s = 1.8 eVee

Preliminary

High Voltage: Exploring DM-electron/nucleus interactions with near single-electron sensitivity achieved in massive bolometers operated underground (low-background environment ~ 1 - 0.1 DRU).

Goal #4: Operation at high voltage (~100 V)

First EDELWEISS DM-electron scattering and absorption results expected by fall 2019.

J. Billard (IPNL)

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Conclusions

From the last few years, there has been an increasing interest in the low-mass dark matter region motivated by lack
f evidence of new physics (e.g. LHC, DM searches, …):
Beyond the standard WIMP Dark Matter scenario
The EDELWEISS-SubGeV program aims at probing this new region of interest with detectors able to provide:
Particle identification and surface event rejection down to 50 eVnr (Low Voltage)
Single-e/h sensitivity on massive bolometers (High Voltage)
The low-voltage R&D program is now focusing on the front-end HEMT preamplifier and electrode design
first detector prototypes achieving 10 eV heat and 20 eV ionization resolutions by 2020 (Ricochet-CryoCube)
Goal is to reach to reach O(10-43) cm2 from 1 GeV to 10 GeV with 1 kg payload in one year at Modane
The high-voltage R&D program is near single-e/h sensitivity on 33.4 g and 200 g Ge crystals operated at Modane.
First science results expected in fall 2019 !

Take away points:

J. Billard (IPNL)

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Back-up

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Energy [keV] 1 2 3 4 5 6 7 8 Event rate [evts/kg/keV/day)]

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Data Noise induced triggers Residual

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24h above-ground with moderate lead shield Not efficiency corrected

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)

5.90 keV

34 eV (RMS)

6.49 keV

34 eV (RMS)

Trigger threshold: 55 eV

Goal #2: Heat energy resolution 10 eV (rms)

J. Billard (IPNL)

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Energy [keV] 1 2 3 4 5 6 7 8 Event rate [evts/kg/keV/day)]

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10 0.05 0.1 0.15 0.2

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Data Noise induced triggers Residual

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24h above-ground with moderate lead shield Not efficiency corrected

E. Armengaud et al., Phys. Rev. D 99, 082003 (2019)

5.90 keV

34 eV (RMS)

6.49 keV

34 eV (RMS)

Trigger threshold: 55 eV

Goal #2: Heat energy resolution 10 eV (rms)

J. Billard (IPNL)