SubGeV Dark Maer searches with EDELWEISS C. Nones on behalf of the EDELWEISS collaboraon Outline • The scienfic context • EDELWEISS-III : setup & FID detectors • From EDW-III to EDW-SubGeV – Axion-like limits – Above-ground ac?vi?es: EDW-Surf – LSM results: EDW R&D • Conclusions and Prospec?ves 2 EDELWEISS-SubGeV:The scienfic Scientific context context eV keV MeV GeV TeV Absorption DM-electron scattering DM-Nucleus scattering Electronic recoil Electronic recoil Nuclear recoil Hidden sector Dark Matter and others Standard WIMP 8B neutrinos (~ 6 GeV) Reactor neutrinos (~ 2.7 GeV) EDELWEISS-SubGeV program Not competitive with High Voltage Low Voltage High Voltage Low Voltage noble gases experiments single e/h Part. ID + Fid single e/h Part. ID + Fid 3 Courtesy of J. Billard J. Billard (IPNL) 2 The EDELWEISS setup • LSM: Deepest site in Europe: 4800 m.w.e., 5 µ/m2/day • Clean room + deradonized air Radon monitoring down to few mBq/m3 • Ac?ve muon veto (>98% coverage) on mobile shield • External (50 cm) + internal polyethylene shielding Thermal neutron monitoring with 3He detector • Lead shielding (20 cm, including 2 cm Roman lead) • Selec?on of radiopure material Cryostat can host up to 40 kg detector at 18 mK Performance of the EDELWEISS-III experiment for direct dark maDer searches [JINST 12 (2017) P08010] 4 EDELWEISS-III detectors measuring heat & ionisation: surface event suppression: Update on the EDELWEISS Dark Matter SearchFully InterDigitized ~870g HPGe detectors Bulk: charges collected by C1 and C2; V and V act as veto The EDELWEISS-III detectors Top=18mK 1 2 Surface: charges collected by either C1V1 or C2V2 Klaus Eitel on behalf of the EDELWEISS collaboration Heat: ΔT = E/Ccal C1:+4V V1:-1.5V Heat: ΔT = E/C heat 870 g Ge NTD EDELWEISS-III New result: ALP limits 2 GeNTD heat sensors Ge e- EDELWEISS-LT program electrodes: c New result: concentric Al rings Sub-GeV WIMP limit at surface ionization (2mm spacing) B covering all faces KIT – The ResearchIonizaon: University in the HelmholtzNpairs Association = E/εγ or εn www.kit.edu FID800 h+ S Operated at J Low Temp Phys (2014)176:182 Ø=70mm, h=40 mm NTD Phys.Lett.BT = 18 681 (2009)mK 305 C :-4V V :+1.5V Ionizaon: 2 2 7 29 August 2018 Klaus Eitel - Update on the EDELWEISS DM Search TeVPA 2018, Berlin • εγ = 3 eV/(e-hole pair) for electron recoils (γ,β) • εn ~ 12 eV /(e-hole pair) for nuclear recoils (neutrons, WIMPs) • εγ/εn = ionizaon quenching Q ➞ Eion = Q Erecoil in keVee Heat: • direct measurement of ALL the energy, irrespec?ve of par?cle ID 5 EDELWEISS-SubGeV:The EDELWEISS ScientificSubGeV context programme eV keV MeV GeV TeV Absorption DM-electron scattering DM-Nucleus scattering Electronic recoil Electronic recoil Nuclear recoil Hidden sector Dark Matter and others Standard WIMP 8B neutrinos (~ 6 GeV) Reactor neutrinos (~ 2.7 GeV) EDELWEISS-SubGeV program Not competitive with High Voltage Low Voltage High Voltage Low Voltage noble gases experiments single e/h Part. ID + Fid single e/h Part. ID + Fid 6 Courtesy of J. Billard J. Billard (IPNL) 2 EDELWEISS-SubGeV:Electron Scientific contextrecoil analysis: axion-like limits eV keV MeV GeV TeV Emission of axions/ALPs from the Sun PRD 98 082004 (2018) Absorption DM-electron scattering DM-Nucleus scattering Electronic recoil Electronic recoil Nuclear recoil Hidden sector Dark Matter and others Standard WIMP 8B neutrinos (~ 6 GeV) Reactor neutrinos (~ 2.7 GeV) Absorp'on of EDELWEISS-SubGeVkeV-scale program Bosonic DM Not competitive with High Voltage Low Voltage High Voltage Low Voltage noble gases experiments • single Best Ge-e/h Part. ID based+ Fid limitsingle e/h < 6 Part. IDkeV + Fid (thanks to J. Billard (IPNL) 2 surface rejec?on) • Start to explore < 1 keV • Surface rejec?on (i.e. ionizaon resolu?on) very important to reduce low-energy ER backgrounds • Improvements foreseen in the 100 eV – 1 keV region with improved ionizaon (here: σ = 35 eVee with HEMT readout) 7 EDELWEISS-SubGeV: Scientific context eV keV MeV GeV TeV Absorption DM-electron scattering DM-Nucleus scattering EDELWEISS SubGeV program Electronic recoil Electronic recoil Nuclear recoil Hidden sector Dark Matter and others Standard WIMP 8B neutrinos (~ 6 GeV) Reactor neutrinos (~ 2.7 GeV) • Current+futureEDELWEISS-SubGeV program projects: background limited Not competitive with High Voltage Low Voltage High Voltage Low Voltage noble gases experiments single e/h Part. ID + Fid single e/h Part. ID + Fid J. Billard (IPNL) 2 • Event-by-event rejec?on even at 1 GeV/c2 and 10-43 cm2 requires a new generaon of detectors • An event-by-event rejecon with ~1 kg.y requires σphonon = 10 eV and σion = 20 eVee n Keeping the ability to apply HV to EDELWEISS detectors is important to reduce thresholds in ER searches • For NR: depends a lot on quenching n Reducing the detector from 860 to 33 g is worth it if the resoluIon goals are met 8 EDELWEISS-SubGeV: Scientific context eV keV MeV GeV TeV Absorption DM-electron scattering DM-Nucleus scattering EDELWEISS SubGeV program Electronic recoil Electronic recoil Nuclear recoil Hidden sector Dark Matter and others Standard WIMP 8B neutrinos (~ 6 GeV) Reactor neutrinos (~ 2.7 GeV) • Current+futureEDELWEISS-SubGeV program projects: background limited Not competitive with High Voltage Low Voltage High Voltage Low Voltage noble gases experiments single e/h Part. ID + Fid single 3 main e/h Part. ID + Fid pillars to be reached by the EDELWEISS detectors J. Billard (IPNL) 2 • Event-by-event rejec?on even at 1 GeV/c• Heat energy resolu?on : 10 eV (RMS) 2 and 10-43 cm2 requires a new generaon of detectors • EM background rejec?on (LV mode) > 103 : 20 eV • Operaon at high voltages (HV mode): 100V Two running modes • An event-by-event rejecon with ~1 Low Voltage: Par?cle ID – ER/NR/ kg.yunknown requires backgrounds + fiducializaon σphonon = 10 eV and High Voltage: single e/h σion = 20 sensi?vityeVee thanks to the Neganov-Luke mode n Keeping the ability to apply HV to EDELWEISS detectors is important to reduce thresholds in ER searches • For NR: depends a lot on quenching n Reducing the detector from 860 to 33 g is worth it if the resoluIon goals are met 9 How to reach 10 eV phonon resolu?on • Intense above ground R&D on NTD sensor • Development of a detailed thermal model for the heat channel to op?mise the choice of the best configuraon • Test of different glues • Inves?gaon of alternave sensors: NbSi TES • Limited by FET current noise: replacing JFETs @ 100K with HEMTs @ 1K should provide addi?onal x2 needed in resoluon 10 09/05/2019 From EDW-III to EDW-SubGeV program Ø Excellent performance of surface + ER rejection via ionization Ø Ionization resolution is key for rejection of backgrounds Ø Heat resolution (and exposure) limited by cryogenic noise 2 Ø NR backgrounds: too large for searches with MWIMP > 10 GeV/c , not a problem for lighter masses Ø Large heat-only background parametrized • Progressing below 1 GeV/c2 and 10-43 cm2 àRequires a new generation of detectors with event-by-event rejection • Reaching 10-43 cm2 @ 1 GeV/c2 with discrimination à Requires sphonon = 10 eV and sion = 20 eVee (assuming Lindhard Q) 08/05/2019 9 EDW Surface R&D: qR&D @ IPN-Lyon Technological developments for both surface DM (EDW-Surf) & coherent EDELWEISS-Surf: an above-ground DM search elastic neutrino-nucleon scattering experiment (Ricochet) E. E. Olivieri • Easy-access surface lab @ IPN-Lyon • Above ground lab : et al., NIM • <1 m overburden: ideal for SIMP search (strongly <1 m overburden interac?ng DM) A858 (2017) 73 (2017) A858 • Dry cryostat (CryoConcept• Dry) with <30h cool-down (fast cryostat (Cryoconcept) turnover ideal for detector R&D) RED20 (33g) • Vibration mitigation : ] • Vibraon mi?gaon: < µg/√Hz vibraon levels obtained in R. suspended tower Maisonobe spring-suspended tower RED11 (200g) • RED20: 33.4 g Ge with NTD sensor, with no electrode • Ge detector mass = 33.4 g RED20 et al., JINST – No ER/NR discriminaon, but no uncertainty due to • Phonon sensor: GeNTD ionizaon yield or charge trapping GeNTD 13 (2018) no.08, T08009 • Low energy calibraon: • Low energy calibration: – 55Fe x-ray source for calibraon o Fe55 X-ray source – Ge neutron ac?vaon o Ge neutron activation • 55Fe Ge 33.4 g Small 0.03 kg.day exposure h=20mm Ø=20mm 08/05/2019 10 Phys. Rev. D 99, 082003 (2019) 11 COSSURF May, 2019 5 RED20 11 Single 33.4g Ge detector (20mm x 20mm) with neutron- transmutation-doped Ge (Ge-NTD) phonon sensor Pulses, calibraon, resolu?on and energy spectrum • Op?mal filter fit to pulses 200 eV pulse 26 0.65 • 24 0.6 Stability of noise & resolu?on over 22 0.55 137h of data taking 20 0.5 Trigger rate [Hz] • 1 day set aside a priori for blind 18 0.45 16 0.4 search Baseline energy resolution [eV] Measured 14 0.35 • Baseline: σ = 17.8 eV Expected from OF theory 12 0.3 Calibration and Resolution 0 20 40 60 80 12100 120 Time [hour] [Credit: Julien Billard] Bradley J Kavanagh (GRAPPA) Tiny, tough WIMPs with EDELWEISS-surf LHC Results Forum - 3rd June 2019 7 18 eV RMS energy10 resolutionData Noise induced triggers 6 6 10 10 Residual 105 0.4 4 105 10 Efficiency 0.05 0.1 0.15 0.2 Event rate [evts/kg/keV/day)] 0.3 104 60 eV analysis 0.2 0 1 2 3 4 5 6 7 8 threshold Energy [keV] 12 Trigger and Livetime Calibrated with low energy X-rays from 55Fe + ∆χ2 cuts 0.1 + χ2 cut normal No ionisation read-out (only phonons) - Analysis threshold total deposited energy is collected, 0 allowing for a low threshold 10−1 1 60 eV energy threshold Energy [keV] Bradley J Kavanagh (GRAPPA) Tiny, tough WIMPs with EDELWEISS-surf LHC Results Forum - 3rd June 2019 Filling the SubGeV region