Testing DAMA/LIBRA signal with ANAIS-112 M. Martinez, On behalf of - PowerPoint PPT Presentation

Testing DAMA/LIBRA signal with ANAIS-112 M. Martinez, On behalf of the 3rd IBS-MultiDark-IPPP Workshop, ANAIS coll. 21-25 November 2016, Lumley Castel, Durham

OUTLINE • The ANAIS program • Detectors performance Received at LSC in Dec 2012 • Background • ANAIS-112 status & prospects • Summary Received at LSC in March 2015 J. Amaré, S. Cebrián, C. Cuesta, E. García, M. Martínez, M.A. Oliván, Y. Ortigoza, A. Ortiz de Solórzano, J. Puimedón, M.L. Sarsa, J.A. Villar, P. Villar M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 2

• The ANAIS program • Detectors performance Received at LSC in Dec 2012 • Background • ANAIS-112 status & prospects Received at LSC in March 2015 • Summary M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 3

ANAIS: A nnual Modulation with NaIS cintillators Confirmation of DAMA-LIBRA modulation signal: • same target and technique • different experimental approach • different environmental conditions affecting systematics Received at LSC in Dec 2012 ANAIS Received at LSC in March 2015 3x3 matrix of 12.5 kg cylindrical NaI(Tl) modules At Canfranc Underground Laboratory (112.5 kg of active mass) (SPAIN) 2450 m.w.e. M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 4

The ANAIS program ANAIS-112 2 X 12.5 kg Alpha Spectra Inc. ANAIS-25 Received at LSC in Dec 2012 9.6 kg ANAIS-0 Saint-Gobain Received at LSC in March 2015 DM-32 ANAIS-112 ANAIS-37 9 X 12.5 kg 3 X 12.5 kg Alpha Spectra Inc. 10.7 kg Alpha Spectra Inc. BICRON M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 5

ANAIS detectors 12.5 kg NaI(Tl) modules: • built @ AS, Co (US) from NaI selected powder • 4. 75” φ x 11.75” length cylindrical shape • OFE copper encapsulation+ Teflon diffusor • Mylar window for low energy calibration Received at LSC in Dec 2012 • Two optical windows for PMT coupling • PMTs: Ham12669SEL2 with high quantum efficiency (>33%) and low dark current Electroformed copper PMT housing made at LSC facility Received at LSC in March 2015 no light guides to increase light collection Voltage dividers made of Cuflon PCB M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 6

Experimental features High duty cycle Muon-tagging system ANAIS-25 25-III III Individual PMT signals digitized 2GS/s with high resolution (14 bits) Down time (4%) Live time (95.2%) Dead time (0.8%) Received at LSC in Dec 2012 Radon-free low energy Robust algorithm for peak calibration system identification @ low Energy! Received at LSC in March 2015 Electronics: Monitor environmental parameters: Air conditioned room to (External radon air content, humidity, temperature (inside/outside/electronics), pressure, antiradon N 2 flux, decouple from temperature PMT HV, gain, trigger rate and level, coincidence window fluctuations M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 7

• The ANAIS program • Detectors Received at LSC in Dec 2012 performance • Background • ANAIS-112 status & Received at LSC in March 2015 prospects • Summary M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 8

Detectors @ LSC so far • D0 / D1 modules : First AS modules grown with purified NaI powder under 90ppb Dec 2012: ANAIS-25 set-up • D2 module : WIMPScint-II powder, Improved protocols Received at LSC in Dec 2012 to reduce 210 Pb March 2015 : ANAIS-37 set-up (D0+D2+D1) • D3 module : WIMPScint-III powder, Improved powder purification to reduce potassium Received at LSC in March 2015 March 2016: ANAIS-37 set-up (D0+D3+D2) • D4 / D5 modules : WIMPScint-III powder just arrived @ LSC M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 9

Light Collection: excellent!! Light collected Detector setup (phe/keV) @ 22 keV ANAIS25 15.6 ± 0.2 15.3 ± 0.1 D0 ANAIS37 ANAIS37 15.1 ± 0.1 Received at LSC in Dec 2012 ANAIS25 (*) 12.6 ± 0.1 15.2 ± 0.1 D1 ANAIS25 ANAIS37 14.4 ± 0.1 D2 ANAIS37 15.4 ± 0.1 15.2 ± 0.5 D3 ANAIS37 Received at LSC in March 2015 (*)PMT: Ham R11065 All AS Detectors in all setups : Excellent light collection that translates into good energy resolution and threshold M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 10

Energy threshold • Data selection at Low E: multiparametric cut • Trigger threshold below 1 keV with high trigger efficiency -Number of peaks in the pulse (>2 per PMT) -Temporal parameters of the total light pulse Trigger efficiency determined by coincidences between high energy gammas and low energy -Asymmetry in the light sharing events in adjacent modules. Received at LSC in Dec 2012 Counts/bin Robust acceptance efficiency Estimate (during 109 Cd/ 57 Co calibrations) Acceptance efficiency after cuts 1.0 0.9 keV 0.8 Received at LSC in March 2015 0.6 D0 0.4 D1 0.9 keV events: D3 0.2 D2 0.0 0 2 4 6 8 10 PMT2 PMT1 Energy (keV) M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 11

Energy calibration: linearity Counts/bin Linear calibration down to 0.9 keV! D0 events 109 Cd Checked with calibration lines & internal lowE depositions Received at LSC in Dec 2012 D0 D0 events Counts/bin 22 Na Received at LSC in March 2015 40 K Residual (keV) M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 12

• The ANAIS program • Detectors performance Received at LSC in Dec 2012 • Background • ANAIS-112 status & prospects Received at LSC in March 2015 • Summary M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 13

Detector internal contaminants 40 K 238 U 210 Pb 232 Th 5 𝜈 Bq/kg ( 220 Rn- 216 Po) 1.4 mBq/kg D0 9 𝜈 Bq/kg 3.15 mBq/kg 3 𝜈 Bq/kg ( 212 Bi-Po) (45 ppb K) 1.1 mBq/kg D1 Received at LSC in Dec 2012 9 𝜈 Bq/kg 4 𝜈 Bq/kg ( 220 Rn- 216 Po) 3.15 mBq/kg (34 ppb K) ≈ 1 𝜈 Bq/kg ( 220 Rn- 216 Po) 1.1 mBq/kg 2.7 D2 0.70 mBq/kg 𝜈 Bq/kg ≈ 1 𝜈 Bq/kg ( 212 Bi-Po) (34 ppb K) ≈ 0,6 𝜈 Bq/kg ( 220 Rn- 216 Po) 0.6 mBq/kg D3 ~ 4 𝜈 Bq/kg ~ 1.8 mBq/kg (19 ppb K) ≈ 0,6 𝜈 Bq/kg ( 212 Bi-Po) Received at LSC in March 2015 • Very good levels of 238 U & 232 Th • Acceptable levels of 40 K (improved in last module to the DAMA upper limit) • 210 Pb out-of-equilibrium contamination, improved in D2, but increased again in D3 M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 14

Detector internal contaminants 40 K 238 U 210 Pb 232 Th 5 𝜈 Bq/kg ( 220 Rn- 216 Po) 1.4 mBq/kg D0 9 𝜈 Bq/kg 3.15 mBq/kg 3 𝜈 Bq/kg ( 212 Bi-Po) (45 ppb K) 1.1 mBq/kg D1 Received at LSC in Dec 2012 9 𝜈 Bq/kg 4 𝜈 Bq/kg ( 220 Rn- 216 Po) 3.15 mBq/kg (34 ppb K) ≈ 1 𝜈 Bq/kg ( 220 Rn- 216 Po) 1.1 mBq/kg 2.7 D2 0.70 mBq/kg 𝜈 Bq/kg ≈ 1 𝜈 Bq/kg ( 212 Bi-Po) (34 ppb K) ≈ 0,6 𝜈 Bq/kg ( 220 Rn- 216 Po) 0.6 mBq/kg D3 ~ 4 𝜈 Bq/kg ~ 1.8 mBq/kg (19 ppb K) ≈ 0,6 𝜈 Bq/kg ( 212 Bi-Po) 2.0 Received at LSC in March 2015 D3 Projected value 1.8 Alpha Rate (mBq/kg) D3 1.6 210 Po activity 1.4 1.2 is being built 1.0 D2 0.8 0.6 0.4 0.2 0.0 0 100 200 300 400 500 600 th March 2015) Days (since 12 M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 15

Studying 210 Pb contamination Origin of the 210 Pb contamination is under study in collaboration with AS → 1 kg crystals tests at LSC Received at LSC in Dec 2012 Received at LSC in March 2015 Two of the samples measured by now are below 0.7 mBq/kg (D2 level) M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 16

Background @ low E Dominated by 210 Pb (continuum) & 40 K (peak) contaminations in the crystal Cosmogenics still decaying in D3 Received at LSC in Dec 2012 Received at LSC in March 2015 Working to improve filtering protocols below 2 keV M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 17

Background budget D0 module D2 module D3 module Received at LSC in Dec 2012 D2 module Received at LSC in March 2015 In all detectors: continuum excess at low energy can be explained by including 3 H and 210 Pb at a surface depth from 10-100 𝝂 m Eur. Phys. J. C (2016) 76:429 M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 18

• The ANAIS program • Detectors performance Received at LSC in Dec 2012 • Background • ANAIS-112 status & prospects Received at LSC in March 2015 • Summary M. Martínez, U. La Sapienza (Roma) – 3rd IBS-MultiDark-IPPP Workshop, 21-25 November 2016, Lumley Castel, Durham 19