Studies for a Xenon1t Studies for a Xenon1t Darkmatter Detector - PowerPoint PPT Presentation

Studies for a Xenon1t Studies for a Xenon1t Darkmatter Detector Darkmatter Detector Marijke Haffke University Zürich

Structure Structure . Introduction Ι . Introduction Ι ΙΙ . Gamma Measurements: 3”NaI ΙΙ . Gamma Measurements: 3”NaI ΙΙΙ . Neutron Measurements: 11”NaI ΙΙΙ . Neutron Measurements: 11”NaI Ι V. Summary & Outlook Ι V. Summary & Outlook Marijke Haffke Uni Zürich 2

Ι. Introduction Ι. Introduction Xenon Xenon • Dual-phase detector with liquid XENON • In Gran Sasso Underground Laboratory, Italy Muon Intensity [m -2 y -1 ] XENON100 3600 mwe Marijke Haffke Uni Zürich XENON1t-Projekt 3 Depth [mwe]

Marijke Haffke Uni Zürich XENON1t-Projekt 4

Projected Sensitivity for Xenon1t Ι. Introduction Ι. Introduction Xenon1t Xenon1t • Next step of Xenon100 Next step of Xenon100 • Fiducial Volume mass: 1t Fiducial Volume mass: 1t • Mass of Liquid Xenon: 3t Mass of Liquid Xenon: 3t • Possible Location: Inside LVD Detector Possible Location: Inside LVD Detector Marijke Haffke Uni Zürich XENON1t-Projekt 5

Ι. Introduction Ι. Introduction Xenon1t Xenon1t • Fiducial Volume: 1t • Total mass liquid Xenon: 3t • Goals: -4 DRU Gamma BG 10 Neutron BG 1 / (2 years) Exposure 2 years -47 cm 2 WIMP sensitivity (100GeV) 3 * 10 Possible Location: Large Volume Detektor (LVD) in Gran Sasso Laboratory Large Volume Detektor (LVD) in Gran Sasso Laboratory Marijke Haffke Uni Zürich XENON1t-Projekt 6

Ι. Introduction Ι. Introduction Xenon1t Xenon1t • Large Volume Detector • Hall A of the Gran Sasso Laboratory • Aim: Detecting stellar Hall C collapses, high energy neutrinos Hall B • Dimensions: 49 m long Hall A LVD 13 m high 12 m wide Marijke Haffke Uni Zürich 7

Ι. Introduction Ι. Introduction LVD LVD • Large Volume Detector Large Volume Detector • Hall A of the Gran Sasso Laboratory Hall A of the Gran Sasso Laboratory • Aim: Detecting stellar collapses, high Aim: Detecting stellar collapses, high energy neutrinos energy neutrinos • Dimensions: 49 m long Dimensions: 49 m long 13 m high 13 m high 12 m wide 12 m wide Marijke Haffke Uni Zürich XENON1t-Projekt 8

Ι. Introduction Ι. Introduction LVD LVD • Large Volume Detector Large Volume Detector • Hall A of the Gran Sasso Laboratory Hall A of the Gran Sasso Laboratory • Aim: Detecting stellar collapses, high Aim: Detecting stellar collapses, high energy neutrinos energy neutrinos • Dimensions: 49 m long Dimensions: 49 m long 13 m high 13 m high 12 m wide 12 m wide Marijke Haffke Uni Zürich XENON1t-Projekt 9

Structure Structure . Introduction Ι . Introduction Ι ΙΙ . Gamma Measurements: 3”NaI ΙΙ . Gamma Measurements: 3”NaI - Fluxes - Activity LVD CF . Neutron Measurements: 11”NaI ΙΙΙ . Neutron Measurements: 11”NaI ΙΙΙ Ι V. Summary & Outlook Ι V. Summary & Outlook Marijke Haffke Uni Zürich 10

Ι. Gamma Measurements Ι. Gamma Measurements Fluxes Fluxes • 3“ NaI PMT NaI MCA Marijke Haffke Uni Zürich 11

Gamma Measurements Gamma Measurements Fluxes Fluxes • Measured positions with NaI Measurement in the Measurement in the Measurement in Marijke Haffke Uni Zürich 12

Ι. Gamma Measurement Ι. Gamma Measurement NaI - Measurements NaI - Measurements • Measurements LNGS Measurements LNGS LVD CF up to factor 100 lower Gamma BG Marijke Haffke Uni Zürich 13 Yiea-Funk Te

ΙI. Gamma Measurements ΙI. Gamma Measurements Activity LVD Activity LVD • Calculation of radio activity in LVD CF • Monte-Carlo Method: – NaI detector simulated inside LVD – 10 7 Decays started from PortaTanks each for U, Th, Co, K – comparison of simulated data with real data Marijke Haffke Uni Zürich 14

ΙI. Gamma Messungen ΙI. Gamma Messungen Aktivität LVD Aktivität LVD • Für MC – Simulationen => Bestimmung der Radioaktivität in der LVD CF • Monte-Carlo Methode: – NaI Detektor im LVD simulieren – Spektren mit echten Daten vergleichen Marijke Haffke Uni Zürich 15

ΙI. Gamma Messungen ΙI. Gamma Messungen Aktivität LVD Aktivität LVD Tl-208 2614.5 60 Co: ≤ 9 mBq/kg 40 K: 290 mBq/kg 232 Th: 78 mBq/kg 238 U: 357 mBq/kg - Data and MC in good agreement - Determination of the activity of relevant Isotopes from MC Marijke Haffke Uni Zürich 16

ΙI. Gamma Messungen ΙI. Gamma Messungen Aktivität LVD Aktivität LVD Tl-208 2614.5 Screening Porta Tank Steel 60 Co: ≤ 9 mBq/kg 60 Co: 1,4 mBq/kg 40 K: 290 mBq/kg 40 K: 210 mBq/kg 232 Th: 78 mBq/kg 232 Th: 20 mBq/kg 238 U: 25 mBq/kg 238 U: 357 mBq/kg - Screening in good agreement for Co and K - Difference for U → environmental Rn Marijke Haffke Uni Zürich 17

Structure Structure . Introduction Ι . Introduction Ι ΙΙ . Gamma Measurements: 3”NaI ΙΙ . Gamma Measurements: 3”NaI - Fluxes - Activity LVD CF ΙΙΙ . Neutron Measurements: 11”NaI ΙΙΙ . Neutron Measurements: 11”NaI - Calibration - Calibration - BG Measurement - BG Measurement Ι V. Summary & Outlook Ι V. Summary & Outlook Marijke Haffke Uni Zürich 18

ΙII. 11”NaI NaI ΙII. 11” Motivation Motivation Gamma and Neutron Measurements with NaI in Frejus: • Ohsumi et al., Gamma-ray flux in the Frejus underground laboratory measured with NaI detector, Nucl. Instr. & Meth. Sec. A NaI crystall (ø 27,7 cm, 33 cm height) 7 PMTs Marijke Haffke Uni Zürich 19

ΙII. 11”NaI NaI ΙII. 11” Electronics Electronics DAQ (Maestro) MCA HV Linear Spectroscopy Amplifier Voltage Divider FAN IN/FAN OUT Marijke Haffke Uni Zürich 20

ΙII. 11”NaI NaI ΙII. 11” Electronics Electronics HV Voltage Divider PMTs FAN IN/FAN OUT Spectroscopy Amplifier MCA PC (Maestro) Marijke Haffke Uni Zürich 21

ΙII. 11”NaI NaI ΙII. 11” Calibration Calibration 11“ NaI 3“ NaI Marijke Haffke Uni Zürich 22

ΙII. 11”NaI NaI ΙII. 11” Calibration Calibration 11“ NaI Energy Resolution Sigma= 0.43 + 1.7 √(Energy) Energy Resolution Resolution [keV] 11“ NaI 3“ NaI 3“ 583 17 % 7,56 % NaI 1000 13 % 5,7 % 2600 7,9 % 3,51 % Marijke Haffke Uni Zürich 23

ΙII. 11” NaI NaI ΙII. 11” Calibration AmBe Calibration AmBe 9 Be(�,n�) 12 C 1 H(n,�) 2 H 4438 keV 2225 keV 23 Na(n,�) 24 Na 6959 keV 127 I(n,�) 128 I 6826 keV Single- Escape (4438 - 511)keV Marijke Haffke Uni Zürich 24

ΙII. 11” NaI NaI ΙII. 11” Calibration AmBe Calibration AmBe • Signal from neutrons Signal from neutrons between 6 and 12 MeV between 6 and 12 MeV • Counts in this region after Counts in this region after BG subtraction: BG subtraction: • 3.5 counts/s 3.5 counts/s • Source 2000 n/s Source 2000 n/s • ~ ¼ reach NaI: ~ ¼ reach NaI: • ~ 0.7 % efficiency ~ 0.7 % efficiency Marijke Haffke Uni Zürich 25

ΙII. 11” NaI NaI ΙII. 11” BG Measurement BG Measurement • Actual position underground: – Next to XenonBox Marijke Haffke Uni Zürich 26

ΙII. 11” NaI NaI ΙII. 11” BG Measurement BG Measurement • Actual position underground: – Next to XenonBox Marijke Haffke Uni Zürich 27

ΙII. 11” NaI NaI ΙII. 11” BG Measurement BG Measurement • Above 4 MeV count rate > 3600 events/h • Expected neutron rate 0.15 events/h • Expected muon rate 0.05 events/h • => electronic origin, not physical Marijke Haffke Uni Zürich 28

ΙII. 11” NaI NaI ΙII. 11” BG Measurement BG Measurement • Module Test → PMTs Single PMT: 53 – 630 events/h NOT coincident in time => Coincidence Marijke Haffke Uni Zürich 29 System

ΙII. 11” NaI NaI ΙII. 11” BG Measurement BG Measurement HV Voltage Divider PMTs MCA FAN IN/OUT Spectroscopy B || A Amplifier Gate || IN PC (Maestro) FAN IN/FAN OUT Discriminator NIM to TTL Amplifier AND Marijke Haffke Uni Zürich 30

Structure Structure . Introduction Ι . Introduction Ι ΙΙ . Gamma Measurements: 3”NaI ΙΙ . Gamma Measurements: 3”NaI - Fluxes - Activity LVD CF ΙΙΙ . Neutron Measurements: 11”NaI ΙΙΙ . Neutron Measurements: 11”NaI - Calibration - BG Measurement Ι V. Summary & Outlook Ι V. Summary & Outlook Marijke Haffke Uni Zürich 31

V. Summary & Outlook Ι V. Summary & Outlook Ι • LVD CF up to factor 100 less gamma flux then HallA • New Neutron detector at XeBox: 11” NaI Outlook • Coincidence Trigger for 11“ → Start Neutron Measurement • Gamma & Neutron Simulation for a Xenon1t detector • Use activities measured and calculated with NaIs Marijke Haffke Uni Zürich 32

IV . Simulations Xe1t IV . Simulations Xe1t Geometry Geometry • Geant4 Geometry: – Outer Cryostat (made of SSteel): 130 cm diameter, 100cm height – Inner Can (made of SSteel): 123 cm diameter, 100 cm height – Inner Teflon Tube: 91 cm diameter, 80 cm height – Liquid Xenon: ~3 t in total ~1 t FV Marijke Haffke Uni Zürich XENON1t-Project 33