Darkside-50, DarkSide-20k and the Global Collaboration to reach the Neutrino Floor with liquid argon

Cristiano Galbiati Gran Sasso Science Institute and Princeton University

The quest for dark matter with liquid argon APC Université Paris Diderot

September 4, 2018

2−10 1−10 1 10 210]2 [TeV/cχM

50−10

49−10

48−10

47−10

46−10

45−10

44−10

43−10

42−10

41−10]2

[cm

SI

σDark Matter-Nucleon

proj.

yrt

DarkSide

-20k 100 proj

.yrt

DarkSide

-20k 200

proj.

yrt

Future 3

00-tonne

GADMC D

etector

1k

DEAP-360

0 proj.

LUX 2017

LZ proj.

PANDAX-I

I 2017

XENON1T

2018

XENONnT

proj.

WARP 200

7

DarkSide

-50 2015

DEAP-360

0 2017

proj.

yrt

Future 3

00-tonne

GADMC d

etector

3k

DarkSide

-50 2018

Neutrino

floor o

n xenon

100 t×yr

101 t×yr

102 t×yr

103 t×yrLHC

1 10]2 [GeV/cχM

46−10

45−10

44−10

43−10

42−10

41−10

40−10

39−10

38−10]2

[cm

SI

σ90% CL upper limit on

DarkSide-LMDarkSide-50 2018NEWS-G 2018 LUX 2017XENON1T 2017 PICO-60 2017PICASSO 2017 CDMSLite 2017CRESST-III 2017 PandaX-II 2016XENON100 2016 DAMIC 2016CDEX 2016 CRESST-II 2015SuperCDMS 2014 CDMSlite 2014COGENT 2013 CDMS 2013CRESST 2012 DAMA/LIBRA 2008Neutrino Floor

3−10 2−10 1−10 1 10 210]2 [TeV/cχM

50−10

49−10

48−10

47−10

46−10

45−10

44−10

43−10

42−10

41−10

40−10

39−10

38−10

37−10]2

[cm

SI

σDark Matter-Nucleon

ATLAS Dijet 2018

ATLAS Dilepton 2018

+ X 2018TmissATLAS E

DarkSide-50 2018

CRESST-III 2017

proj.yrt

DarkSide-2

0k 100

proj.yrt

DarkSide-2

0k 200

proj.yrt

Future 300

-tonne GAD

MC Detecto

r 1k

DEAP-3600

proj.LUX 2

017

LZ proj.

PANDAX-II

2017

XENON1T 20

18

XENONnT pr

oj.

proj.yrt

Future 300

-tonne GAD

MC detecto

r 3k

DarkSide-5

0 2018

DarkSide-LM proj.

Neutrino floor on xenon

direct detection limits at 90% CLATLAS limits at 95% CL

=1DM

=0.01, gl

=0.1, gqgVector mediator, Dirac DM

PandaX-xT

�5

▪ Intermediatestage:▫ PandaX-4T(4-tontarget)withSIsensitivity~10-47cm2▫ On-siteassemblyandcommissioning:2019-2020

TheCathodeHigh-VoltageFeedthrough

TheOuterDetectorPMTs(120)

Dual phase xenon TPC, 7 tonnes fully active

LXeHeatExchanger

ExistingWaterTank,and

SURFInfrastructure

Gadolinium-LoadedLiquidScintillatorVeto

InstrumentationConduits

D-Dneutrontube

The LUX-ZEPLIN detector

Radon dominates ER backgrounds

Gamma backgrounds (PMTs, cryostat) are negligible.

pp solar neutrinos, elastic scattering on atomic electrons

Coherent neutrino scattering on xenon nuclei

LZ backgrounds summary5.6 tonnes, 1000 days

The phases of the XENON Program

8

M. Schumann (AEC Bern) – XENON 8

XENON1T

96cm

● 3.5 t liquid xenon in total● 2.0t active target● ~1t after fiducialization

● 248+6 PMTs

XENON10 XENON100 XENON1T XENONnT

2005-2007 2008-2016 2012-2018 2019-2023

25 kg- 15cm drift 161 kg- 30 cm drift 3200 kg- 100 cm drift

8000 kg-150 cm drift

~10-43 cm2 ~10-45 cm2 ~10-47 cm2 ~10-48 cm2

XENON1T and XENONnT science reach

• XENON1T: 1.6 x 10-47 cm2 with an exposure of 2 tonnes x year

• XENONnT: to start in mid 2019, aiming for 20 tonnes x year exposure

]2

WIMP mass [GeV/c

7 10 20 30 100 200 1000 2000 10000

]2

[c

mσ

WIM

P-n

ucle

on

49−10

48−10

47−10

46−10

45−10

44−10

43−10

PandaX-II (2

017)

LUX (2017)

XENON100 (2016)

y)⋅

XENON1T (0.1 t y)⋅

XENON1T (2 t

y)⋅

XENONnT (20 t

Billard 2013, N

eutrino Disc

overy Limit

Bagnaschi 2016

�9

XENON1T

XENON1T First Result

XENONnTLZ

2016 2018 2020 2022 202410-48

10-47

10-46

10-45

10-44

Calendar Year

Crosssection @ 50GeV [cm2]

Apr2020

Aug2019

Aug2018

Figure 2: A comparison, as function of calendar year, of the projected sensitivity to spin-independent WIMP-nucleon interactions for a 50GeV/c2 WIMP for XENON1T (1 ton fiducialmass), XENONnT (4 ton fiducial mass), and LZ (5.6 ton fiducial mass). Curves in this plot havebeen calculated using the o�cial values that each experiment has estimated for WIMP energyrange, NR acceptance, ER rejection and background. See text for comments on the comparisonof the various curves.

XENON1T XENONnT LZ

Fiducial Volume [tons] 1 4 5.6Livetime Fraction 80% 80% 80%WIMP Energy

4-50 4-50 6-30Range [keVnr]NR Acceptance 40% 40% 50%ER Rejection 99.75% 99.75% 99.5%Bkg rate [evt/year] 2.08 1.15 2.35

Table 1: Assumptions for the projected sensitivity to spin-independent interaction shown inFigure 2. The background rate is defined as the rate of NR and ER falling into the definedWIMP search box, after having accounted for acceptance and rejection, respectively. Numbersfor LZ are the “goal” values extracted from Reference [J.Dobson, 2016].

6

XENON1T Presentation at LNGS on May 28 2018

arxiv:1805.12562

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 361687

Integral 3.576e+05

0

100

200

300

400

500

600

700

800Entries 361687

Integral 3.576e+05

+R 2

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 227934

Integral 2.258e+05

0

100

200

300

400

500Entries 227934

Integral 2.258e+05

+Veto

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 16213

Integral 1.619e+04

0

10

20

30

40

50

60

70Entries 16213

Integral 1.619e+04

14+r<10 cm && 50% loss S2/S1 cut (70d)

Expected number of background events0 2 4 6 8 10

Number of WIMP-like events needed

0

10

20

30

40

50

60

70

80

100% Background Model Errors

10% Background Model Errors

1% Background Model Errors

“Zero Background” condition (<0.1 background events)

necessary to conduct discovery program

]2WIMP mass [TeV/c

2−10 1−10 1 10

]2 [cm

SI

σWIMP-nucleon

50−10

49−10

48−10

47−10

46−10

45−10

44−10

43−10

42−10

41−10

DarkSide-20k

(100 t yr p

roj.)

DarkSide-20k

(200 t yr p

roj.)

Future 300-t

onne GADMC D

etector (100

0 t yr proj.

)

DEAP-3600 (p

roj.)

LUX (2017)

LZ (proj.)

PANDAX-II

(2017)

XENON1T (2

017)

XENON1T (p

roj.)

XENONnT (p

roj.)

WARP (2007)

DarkSide-5

0 (2015)

DEAP-3600 (2

017)

Neutrino f

loor on xe

nonFuture

300-tonne G

ADMC detecto

r (3000 t yr

proj.)

The Global Argon Dark Matter CollaborationArDM DarkSide DEAP MiniCLEAN

}A Single Global Program for Direct Dark Matter Searches Currently taking data: ArDM, DarkSide-50, DEAP-3600 Next step: DarkSide-20k at LNGS (2021-)Last Step: 300 tonnes detector, location t.b.d (2027-)

DarkSide-20k approved by INFN and LNGS in April 2017 and by NSF in Oct 2017 Officially supported by LNGS, LSC, and SNOLab 30 tonnes (20 tonnes fiducial) of low-radioactivity underground argon 14 m2 of SiPM coverage

Questionnaire for Requestingthe Status of Recognized Experiment at CERN

The DarkSide Collaboration &The Global Argon Dark Matter Collaboration

October 24, 2017

Letter of Intent September 8, 2017

Rev B

Scientists at LNGS, LSC, and SNOLAB are joining in an international effort to mount a

phased argon dark matter program with the goal of being sensitive to the neutrino floor. This effort will include a broad collaboration of scientists and will represent the global community for dark matter searches with argon. This letter is an update of a previous communication dating June 2017, which detailed the first conception of the program; this letter was expanded to capture the intent of all institutions and scientists participating in the program.

In this document, the undersigned representatives of groups working on argon dark matter searches, including Brazilian, Canadian, Chinese, French, German, Greek, Italian, Mexican, Polish, Romanian, Russian, Spanish, Swiss, US, and UK groups among others, memorialize their intent to form a Global Argon Dark Matter Collaboration to carry out a program for direct dark matter searches, consisting of two main elements.

The first element of the program is the DarkSide-20k experiment at LNGS, whose science goal is to perform a dark matter search with an exposure of 100 tonne·yr of low-radioactivity underground argon (the low intrinsic background, free from any background other than that induced by atmospheric neutrinos, may also permit a 200 tonne·yr exposure for extended operation). This detector will be competitive with next generation liquid xenon dark matter searches at high WIMPs masses and will be built in time to start data taking by 2021.

The second element of the program is a low-radioactivity underground argon detector with a fiducial mass of a few hundred tonnes. The science goal is to perform a dark matter search with an exposure of 1,000 tonne·yr with sensitivity reaching to the neutrino floor, to identify coherent nuclear scattering of atmospheric neutrinos, and to perform a high-precision measurement of intermediate energy solar neutrinos (pep, CNO, low energy 8B). All groups have agreed to the continuing collaboration towards the development of a depleted argon detector at the scale of a few hundred tonnes, working together to select a design and site based on technical and scientific requirements. Decisions on technical design will be informed by data collected with the precursor DEAP and DarkSide detectors. The groups will also develop low radioactivity argon to allow for the multi-hundred tonne detector.

The proposal to build DarkSide-20k, submitted to the Italian INFN and to LNGS, reviewed well, and INFN and LNGS approved the DarkSide-20k experiment in April 2017. The scope of the INFN contributions is €40M. The proposal submitted to the US NSF reviewed well, and the collaboration is now awaiting the approval decision by the US NSF. The capital funding for DarkSide-20k under discussion with the US NSF is $13M.

Deepundergroundlaboratorysupportforglobalcollaborationtowardsdiscoveryofdarkmatterutilisingliquidargondetectors.Towhomitmayconcern;As hosts of the existing operational liquid argon direct dark matter detectors,and asproponentsandsupportersoftheUnderground-GRIinitiative,theLNGS,SNOLABandLSCdeepundergroundresearchfacilitiesarepleasedtorecognizethecollaborativedevelopmentswithinthegloballiquidargondarkmattercommunity.TheDarkSideprojectatLNGS,theDEAPprojectatSNOLABandtheArDMprojectatLSCarealldevelopingnewtechnologiesandcapabilitiestosearchforWIMPdarkmatter,andarebeginningtocoalesceintoonecollaborationtodevelopfuture, larger generations of liquid argon direct dark matter detectors. We encourage andsupport the development of this global community, with a focus on the development ofDarkSide-20katLNGSinthefirstinstance,andalargerdetectoratalocationtobedeterminedfromscientific requirements, in the future.Usingavailableassayand research infrastructure,thethreedeepundergroundresearchfacilitieswill support theactivitiesanddevelopmentofthevariousgenerationsofliquidargondetectors.

Stefano Ragazzi Director, LNGS

Aldo Ianni Director, LSC Nigel J.T. Smith

Director, SNOLAB

DarkSide-20k20-tonnes fiducial dark matter detectorstart of operations at LNGS within 2021

100 tonne×year background-free search for dark matter

Future 300-tonne Detector300-tonnes depleted argon detector

start of operations within 20261,000 tonne×year background-free search for dark matter

precision measurement of solar neutrinos

20- 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

DS-20k

300k

Urania to Aria to LNGS

• Volatilità relative => 1.007

• Valori tipici >1.5

• Numero di stadi teorici => ordine delle migliaia

• HETP = 10 cm

• H=200-400 m

• Usuali = 20-30 m

• Fuori terra

• A sezioni separate

325

m

Liquid Argon TPC 153 kg 39Ar-Depleted Underground Argon

Target

4 m Diameter 30 Tonnes

Liquid Scintillator Neutron Veto

10 m Height 11 m Diameter 1,000 Tonnes

Water Cherenkov Muon Veto

Liquid Argon TPC 153 kg 39Ar-Depleted Underground Argon

Target

4 m Diameter 30 Tonnes

Liquid Scintillator Neutron Veto

10 m Height 11 m Diameter 1,000 Tonnes

Water Cherenkov Muon Veto

DarkSide-50• P. Agnes et al. (The DarkSide Collaboration), “DarkSide-50 532-day Dark Matter Search with Low-Radioactivity Argon”, arxiv:1802.07198.

• P. Agnes et al. (The DarkSide Collaboration), “Constraints on Sub-GeV Dark Matter-Electron Scattering from the DarkSide-50 Experiment”, arxiv:1802.06998.

• P. Agnes et al. (The DarkSide Collaboration), “Low-mass Dark Matter Search with the DarkSide-50 Experiment”, arxiv:1802.06994.

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 1.907394e+07

Integral 9.899e+06

0

10

20

30

40

50

60

70

80

90

310×Entries 1.907394e+07

Integral 9.899e+06

Quality +Trgtime +S1sat

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 8985498

Integral 4.131e+06

0

1

2

3

4

5

6

7

8

9

310×Entries 8985498

Integral 4.131e+06

+Npulses

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 4147304

Integral 1.838e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 4147304

Integral 1.838e+06

s fidµ+40

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 3881935

Integral 1.71e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 3881935

Integral 1.71e+06

+S1pmf

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 3862264

Integral 1.695e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 3862264

Integral 1.695e+06

+min S2uncorr

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 3855116

Integral 1.688e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 3855116

Integral 1.688e+06

+xy-recon

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 3855060

Integral 1.688e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 3855060

Integral 1.688e+06

+S2 F90

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 3849254

Integral 1.683e+06

0

0.5

1

1.5

2

2.5

3

3.5

310×Entries 3849254

Integral 1.683e+06

+min S2/S1

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 548087

Integral 5.34e+05

0

0.2

0.4

0.6

0.8

1

310×Entries 548087

Integral 5.34e+05

+max S2/S1

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 547837

Integral 5.338e+05

0

0.2

0.4

0.6

0.8

1

310×Entries 547837

Integral 5.338e+05

+S2 i90/i1

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 545966

Integral 5.319e+05

0

0.2

0.4

0.6

0.8

1

310×Entries 545966

Integral 5.319e+05

+S1 TBA

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 543779

Integral 5.297e+05

0

0.2

0.4

0.6

0.8

1

310×Entries 543779

Integral 5.297e+05

+TPB Tail

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 540450

Integral 5.266e+05

0

0.2

0.4

0.6

0.8

1

310×Entries 540450

Integral 5.266e+05

+NLL

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 361687

Integral 3.576e+05

0

100

200

300

400

500

600

700

800Entries 361687

Integral 3.576e+05

+R 2

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 227934

Integral 2.258e+05

0

100

200

300

400

500Entries 227934

Integral 2.258e+05

+Veto

0 50 100 150 200 250 300 350 400 450 500S1 [PE]

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

190

fEntries 16213

Integral 1.619e+04

0

10

20

30

40

50

60

70Entries 16213

Integral 1.619e+04

14+r<10 cm && 50% loss S2/S1 cut (70d)

3−10 2−10 1−10 1 10 210]2 [TeV/cχM

50−10

49−10

48−10

47−10

46−10

45−10

44−10

43−10

42−10

41−10

40−10

39−10

38−10

37−10]2

[cm

SI

σDark Matter-Nucleon

ATLAS Dijet 2018

ATLAS Dilepton 2018

+ X 2018TmissATLAS E

DarkSide-50 2018

CRESST-III 2017

proj.yrt

DarkSide-2

0k 100

proj.yrt

DarkSide-2

0k 200

proj.yrt

Future 300

-tonne GAD

MC Detecto

r 1k

DEAP-3600

proj.LUX 2

017

LZ proj.

PANDAX-II

2017

XENON1T 20

18

XENONnT pr

oj.

proj.yrt

Future 300

-tonne GAD

MC detecto

r 3k

DarkSide-5

0 2018

DarkSide-LM proj.

Neutrino floor on xenon

direct detection limits at 90% CLATLAS limits at 95% CL

=1DM

=0.01, gl

=0.1, gqgVector mediator, Dirac DM

The DarkSide Strategy

• Background-free through the neutrino limit

• Neutrino limit reached with detector of few hundred tonnes located very deep underground

• Complementary science: solar neutrinos

Energy [MeV]1−10×6 1 2 3 4

yr]

× 400 tonne

×Events / [10 keV

1

10

210

310MC Data

AllνBe-7

νCNO-

νpep-νB-8

P32

Radon

Other Cosmogenics

Bq / 100 tonne]µRadon Activity [ 10 20 30 40 50 60 70 80 210 210×2

Uncertainty [%]

0

5

10

15

20

25

30CNO (HZ)

pep (HZ)

Be (HZ)7

CNO (LZ)

pep (LZ)

Be (LZ)7

Ionization-Only (S2-Only) Signals1. The PMTs have zero dark rate at 88 K so a signal is always real

2. The gain in the gas region (~70 PE/e-, reduced to 23 PE/e- when accounting for the 30% QE of the PMTs) means that we are sensitive to a single extracted electron

3. The radioactivity rate in the detector is remarkably low, so …

4. We don’t need PSD

5. The electron yield for nuclear recoils rises at low energy

0 10 20 30 40 50 60 70 80 90S2 [PE]

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5Acceptance

Fiducialization

Trigger efficiency×

<0.15)90

S2 Identification (f×

arxiv:1802.06994

4 e-100 eVeeAnalysis Threshold

0.4 e-10 eVee

10% Detector Threshold

0 0.5 1 1.5 2 2.5 3-eN

2−10

1−10

1

10

210

day]

×

kg

×

- eN

[0.05

/

Events PE

S2=30

Center PMT DS-50 DATAGetter OffGetter OnFit

-1 Ext. e's-2 Ext. e

arxiv:1802.06994

0 20 40 60 80 100-eN

3−10

2−10

1−10

1

10

210

310 day]

× kg

×

- eEvents / [0.5 N

First 100 days

Last 500 days

d)(500Single S2

d)(500S1 + S2

0 50 100-eN

0

0.2

0.4

0.6

day]

× kg

× - e

[N

/ Events

0.01 ± 0.11 = Ratio BR L/K

arxiv:1802.06994

10 20 30 40 50 60 70 80 90 100-eN

0

100

200

300

400

500

600

700

800

900- e

Events / N

AmBe Data241

G4DS Fit

Single S2

S1 + S2

arxiv:1802.06994

10 20 30 40 50 60 70 80 90 100-eN

0

10

20

30

40

50

60

70

80

90

100- e

Events / N

C Data13Am241

G4DS Fit

Single S2

S1 + S2

γC 13Am241

arxiv:1802.06994

3−10 2−10 1−10 1 ε

0

1

2

3

4

5

6

7

8

9

10]

nr

/keV

- [e

yQ

Xe Data

LUX 2016

ZEPLIN-III 2011

XENON10 2011

Manzur et al. 2010

XENON10 2009

Aprile et al. 2006

1 10 210 310] nr [keVXeE

2−10 1−10 1 10 210] nr [keVArE

Ar Data

ARIS

SCENE

AmBe - AmC - ARIS - SCENE

Joshi et al. 2014

Joshi et al. 2014 Cross Calibrated

Xe Model

Bezrukov et al. 2011

arxiv:1802.06994

0 0.5 1 1.5 2 2.5 3310×

Energy [keV]

1

10

210

310

410

510

Events / [2 keV]

Th232 Cryo

K40 Co60

lowU238upU238

U235 Kr85

Ar39 DATA

arxiv:1802.07198

0 5 10 15 20 25 30 35 40 45 50-eN

3−10

2−10

1−10

1

10

210 day]

× kg

×

- eEvents / [N

Data

G4DS MC All

-rays γCryostat

-rays γPMTs

Kr 85Ar + 39

2 cm-40=10χσDM spectra

2=2.5 GeV/cχM

2=5.0 GeV/cχM

2=10.0 GeV/cχM

1 2 3 4 5 6 7 8 9 10 11 12131415] nrE [keV

1 2 3] eeE [keV

1−10

1

10

210

310

day]

× kg

×

ee

Events / [keV

2−10

1−10

1

10

210

day]

× kg

×

nr

Events / [keV

arxiv:1802.06994

1−10×5 1 2 3 4 5 6 7 8 9 10]2 [GeV/cχM

45−10

44−10

43−10

42−10

41−10

40−10

39−10

38−10]2

[cm

SI

σDark Matter-Nucleon

DarkSide-50 BinomialDarkSide-50 No Quenching Fluctuation NEWS-G 2018 LUX 2017XENON1T 2017 PICO-60 2017PICASSO 2017 CDMSLite 2017CRESST-III 2017 PandaX-II 2016XENON100 2016 DAMIC 2016CDEX 2016 CRESST-II 2015SuperCDMS 2014 CDMSlite 2014COGENT 2013 CDMS 2013CRESST 2012 DAMA/LIBRA 2008Neutrino Floor

arxiv:1802.06994

No Quenching

Fluctuations

0.6 keVnr Threshold

Binomial

Fluctuations

0 5 10 15 20 25 30-eN

3−10

2−10

1−10

1

10

210 day]

× kg

×

- eEvents / [N

Data

G4DS MC All

-rays γCryostat

-rays γPMTs

Kr 85Ar + 39

2 cm-36=10χσDM spectra

2=10 MeV/cχM

2=100 MeV/cχM

2=1000 MeV/cχM

0.2 0.4 0.6 0.8 1 1.2] eeE [keV

arxiv:1802.01427

arxiv:1802.06998

10 210 310 [MeV]χM

39−10

38−10

37−10

36−10]2

[cm

eσDark Matter-Electron

=1DMFDarkSide-50XENON100XENON10

arxiv:1802.06998

Drift electric field [V/cm]0 200 400 600 800 1000

S1 yield relative to 0 field

0.7

0.75

0.8

0.85

0.9

0.95

1

1.05

1.1

1.15 57.2 keV

dεParallel to

dεPerpendicular to

ProductionandPurification

Renshaw,PNNLLRUAWorkshop20184

Preliminary lay-out

a^erPOLARISSrl

Production:Urania• Commercial-scaleplanttoextractUAr• LocatedinSouthwesternColorado

• UAr extractedfromCO2 wellgasatthetonne scaleFocusofthistalk Purification:Aria

(seeM.Simeone’s talkfordetails)• 350mtallcryogenicdistillationcolumntopurifyUAr and

isotopicallyseparateargonandotherelements• LocatedinrefurbishedcarbonmineshaftinSardinia,Italy• WillchemicallypurifytheUAr forDS-20ktodetectorgrade

UAr transportedviaboatforfinalpurificationatAria

Renshaw,PNNLLRUAWorkshop201810

EntertheAgeofUrania

• Volatilità relative => 1.007

• Valori tipici >1.5

• Numero di stadi teorici => ordine delle migliaia

• HETP = 10 cm

• H=200-400 m

• Usuali = 20-30 m

• Fuori terra

• A sezioni separate

325

m

Tile

FEBs

Top View

Side View Side View

3D View

Amplitude [Arb.Units]0 50 100 150 200 250 300

Entries

0

200

400

600

800

1000

1200

Gain: 52.68: 2.19bσ

SNR: 24.1

The End