Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama...

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Future SK Program for n e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14

Transcript of Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama...

Page 1: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Future SK Program for ne Physics

Atsuko KibayashiFor the Super-Kamiokande Collaboration

Okayama UniversityJune 14, 2013

1RENO 502013/6/14

Page 2: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

MOTIVATIONS

2013/6/14 RENO 50 2

Page 3: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

8 MeVΔT~20μsVertices within 50cm

γ

p

n

Gde+

ne

Capt

ures

on

Gd

Gd in Water

0.0001% 0.001% 0.01% 0.1% 1%

100%

80%

60%

40%

20%

0%

2013/6/14 3RENO 50

Neutron Capture by Gadolinium

• Large cross section of Gd for neutron capture– ~49,000 barns (0.3 barns on free

proton)• Coincident signal detection to suppress

background

• Beacom and Vagins, Phys. Rev. Lett., 93:171101, 2004]

• 0.1% Gd gives 90% neutron capture eff.

• ~100 ton of Gd2(SO4)3

in SK

Page 4: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Physics of neby GADZOOKS!Gadolinium Antineutrino Detector Zealously Outperforming Old Kamiokande, Super!

• Observation of Supernova Relic Neutrino (SRN)– SRN has not yet been observed

• Supernova Burst Neutrinos – Better direction determination by enhancement of

electron scattering events• Reactor Neutrinos

– Precise measurements of oscillation parameters by high statistics

2013/6/14 RENO 50 4

Page 5: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SRN Spectrum

2013/6/14 RENO 50 5

Expected SRN Spectrum(ne fluxes)

SRN flux calculations Horiuchi st al. PRD, 79, 083013 (2009)

Expected no. of SRN events1.3-6.7 events/year/22.5kton (10-30MeV)

Need: - Large target mass- Background removability

Page 6: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Expected SRN Signal and BackgroundAssume :

• 90 % neutron capture efficiency,

• 74% Gd gamma detection efficiency,

• invisible muon B.G. is 35% of the SK-IV invisible muon B.G.

Expect:

• 10-45 SRN events in 10-years data taking (Evis = 10-30 MeV)

2013/6/14 6RENO 50

Page 7: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SN at 10kpc

ne+p

ne+p

ne+p ne+p

n+e n+e

n+en+e

Supernova Burst Directionw/o Neutron Tagging

Neutrino flux and spectrum from Livermore simulation2013/6/14 7RENO 50

Page 8: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SN at 10kpc

ne+p ne+p

ne+p ne+p

n+e n+e

n+e

n+e

Supernova Burst Directionw/ Neutron Tagging

Removing tagged events

Neutrino flux and spectrum from Livermore simulation2013/6/14 8RENO 50

Page 9: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SN Direction Determination Precision

2x better precision with neutron tagging.

Direction Determination Precision (1000 MC events)

tag eff. = 1.0

tag eff. = 0.8

tag eff. = 0.0

Num

ber o

f sup

erno

vae 振動なし

振動あり(正階層性)振動あり(逆階層性)

Direction Determination Precision

No Osc.Oscillated (normal hierarchy)Oscillated (inverted hierarchy)

2013/6/14 9RENO 50

H. Ishino

Page 10: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Questions

Gd in SK?

• Water transparency?• How to purify Gd water?• How to introduce/remove Gd?• Effect on SK material?• Effect on solar neutrino analysis?• In a water Cherenkov detector?2013/6/14 RENO 50 10

EGADS

Page 11: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

EGADSR&D

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Page 12: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SK water purification system

50m

Super-Kamiokande

To Atotsu entrance

EGADS hall

Parking place

Underground site map2013/6/14 12RENO 50

EGADSEvaluating Gadolinium’s Action on Detector Systems

Page 13: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Gd-water filtration

Gd purification(resin to remove U keeping Gd)

200 m3 SUS tank Transparency measuring device

13

EGADS Lab. in Kamioka Mine

2013/6/14 RENO 50

15 m3 plastic tank(for dissolving Gd)

Gd Removing Resin

Feb.16, 2011

Page 14: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Water Monovalent Multivalent Viruses Bacteria Suspended Ions Ions Solids

Water Monovalent Multivalent Viruses Bacteria Suspended Ions Ions Solids

Water Monovalent Multivalent Viruses Bacteria Suspended Ions Ions Solids

Water Monovalent Multivalent Viruses Bacteria Suspended Ions Ions Solids

Microfiltration1,000 – 100,000 angstroms membrane pore size

Ultrafiltration 100 – 1,000 angstroms membrane pore size

Nanofiltration 10 – 100 angstroms membrane pore size

Reverse Osmosis 5 – 15 angstroms membrane pore size

size

Membrane filter technology

small large

Gd2(SO4)3

M. Vagins

Page 15: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

200 ton EGADS

Main Tank

EGADS Selective Filtration System

Intake Pump

(>4 ton/hr)

5 m 1st Stage

Filter

Concentrated Gd NF Reject Lines

UV#1

Mem

bran

eD

egas

0.2 m 2nd Stage Filter

0.5 ton Collection

Buffer Tank

RepressurizationPump

(>0.6 MPa, >4 ton/hr)

RepressurizationPump

(>0.6 MPa, >3 ton/hr)

Nanofilter #2

Nanofilter #1

Ultrafilter #1

Repressur-izationPump

(>0.9 MPa, >2 ton/hr)

TOC

5 m Filter

0.5 ton Buffer Tank

RO #1

Ultrafilter #1

Ultr

afilte

r #2

Repressurization Pump

(>0.9 MPa, >1.5 ton/hr)

DI#2

5 m Filter

RO #2

RO Permeate Lines

Conveying Pump

(~0.35 MPa, >4 ton/hr)

Recycles RO Reject Lines

Chiller

UF#1 Reject Line

UF#2 Reject

UV#2

DI#1

To Drain

Nanofilter #1

Nanofilter #1

Nanofilter #1

Nanofilter #2Nanofilter #2

Ultr

afilte

r #2

2013/6/14 15RENO 50

M. Vagins

Page 16: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

EGADS (Step 1)200 m3 tank

Gd-water filtration system w/o PMT

Circulation of pure water in 200 m3 tank, to evaluate basic performance of the filtration system

March – June, 2011

15m3 tank

Page 17: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

w/o PMT

Circulation of 0.2% Gd2(SO4)3 dissolved water in15m3 tank through the filtration system

Measurement of Gd-dissolved water transparency August, 2011 – December, 2012

EGADS (Step 2)200 m3 tank

Gd-water filtration system

15m3 tank

Page 18: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

w/o PMT

EGADS (Step 3)200 m3 tank

Gd-water filtration system

15m3 tank

Circulation of 0.2% Gd2(SO4)3 dissolved water in 200m3 tank through the filtration system.

Study of effects on SUS tank (accelerated studies have shown no problems)

December, 2012 – June, 2013

Page 19: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Water Transparency MeasurementMethod

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T. Yano

Page 20: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

SK-III and SK-IV Ultrapure Water = 74.7% - 82.1% @ 15 m

30 k

g o

f G

d2(S

O4) 3

*8H

2O

3

5% n

cap

ture

on

Gd

60 k

g o

f G

d2(S

O4) 3

*8H

2O

5

2% n

cap

ture

on

Gd

89.4

kg

of

Gd

2(S

O4) 3

*8H

2O

6

2% o

n G

d

149

.4 k

g o

f G

d2(S

O4) 3

*8H

2O

7

3% o

n G

d

274

kg

of

Gd

2(S

O4) 3

*8H

2O

8

3% o

n G

d

400

kg

of

Gd

2(S

O4) 3

*8H

2O

8

8% o

n G

d70 % => 85% of pure water

2013/6/14 20RENO 50

M. VaginsLight Remaining at 15 m in 200 ton tank

Page 21: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

240 PMT mounting July - August, 2013

EGADS (Step 4)200 m3 tank

Gd-water filtration system

15m3 tank

Page 22: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Circulation of pure water, then 0.2% Gd2(SO4)3 dissolved water

Integrated test Starting September, 2013

Mini-SK (w/ same SK material)

EGADS (last Step)200 m3 tank

Gd-water filtration system

15m3 tank

Page 23: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

GADZOOKS!for

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Page 24: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Effect on Solar Neutrino Analysis?

• To achieve 3.5 MeV(Kin.) solar neutrino analysis in 0.2% Gd+H2O SK, the following radioactivity levels would be needed.

< 2.8 x 10-11 g(238U)/g(Gd)< 8.6 x 10-11 g(232Th)/g(Gd)< 9.6 x 10-18 g(226Ra)/g(Gd)

=> Corresponds to < 0.35 mBq/kg(Gd)

2013/6/14 RENO 50 24

M. Smy

Page 25: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Radioactivity of Gd2(SO4)3

Radioactivity in Gd2(SO4)3 batches measured in Canfranc [mBq/Kg, limits are @ 95% c.l.] Chain Longest lived

parent in sub-chain

Product 1 Product 2 Product 3 Product 4 Product 5

238U 238U 51 ± 21 < 33 292± 67

74 ± 28 242± 60

226Ra 8 ± 1 2,8 ± 0,6 74± 2 13± 1 13 ± 2232Th 228Ra 11 ± 2 270 ±

16(*)1099± 12 205 ± 6 21 ± 3

228Th 29 ± 3 86 ± 5 504± 6 127 ± 3 374 ± 6235U 235U < 32 < 32 < 112 < 25 < 25

227Ac/227Th 214 ± 10 1700 ± 20 2956 ± 30 1423 ± 21 1750 ± 42 Others 40K 29 ± 5 12 ± 3 (*) 101 ± 10 60 ± 7 18 ± 8

138La 8 ± 1 < 683 ± 15 3 ± 1 42 ± 3176Lu 80 ± 8 21 ± 2 566 ± 6 12 ± 1 8 ± 2

prel

imin

ary

Still

too

high

252013/6/14 RENO 50

L. Labarga

=> To reduce Radium, one solution is to use commercial selective resins available.

Page 26: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Answers

Gd in SK?• Water transparency? • How to purify Gd water? • How to introduce/remove Gd?

• Effect on SK material? • Effect on solar neutrino analysis?

• In a water Cherenkov detector?

2013/6/14 RENO 50 26

85% of pure water

Method being established

Mass removal still under study, commercial resin available

Gd2(SO4)3 proven to be safe

Radioactivity still too high (esp. Ra). Commercial resin will be tested.

Demonstration of Cherenkov detection of Gd(n, gamma) Gd (H.Watanabe et al. Astropart. Phys., 31, 320-328 (2009)

Page 27: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

R&D Schedule

2013/6/14 RENO 50 27

M. Nakahata

Page 28: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Conclusion• For SRN detection

– A large target volume is needed => SK is the only one w/ that kind of volume– Addition of Gd unable us to detect SRN

• For SN detection– Direction accuracy can be improved by tagging ne events

2013/6/14 RENO 50 28

Gd in water Cherenkov detector R&D project (EGADS) is in progress.Gd in SK looks more and more promising.

We hope to start GADZOOKS! in a few years.

As soon as EGADS successfully demonstrates the feasibility for GADZOOKS!, schedule for GADZOOKS! will be discussed among the SK collaboration.

Page 29: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

BACKUPS

2013/6/14 RENO 50 29

Page 30: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

EGADS Members• ICRR, University of Tokyo

– Y. Kishimoto , M. Nakahata, H. Sekiya• Kavli, IPMU

– L. Marti, M. Vagins• Kobe University

– Y. Takeuchi• Okayama University

– H. Ishino, A. Kibayashi, Y. Koshio, T. Mori, M. Sakuda, Y. Yamada, T. Yano,• University Autonoma Madrid

– L. Labarga, P. Fernadez• University of California, Irvine

– G. Carminati, J. Griskevich, B. Kropp, A. Renshaw, M. Smy, P. Weather

2013/6/14 RENO 50 30

Page 31: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Ultrafilter Nanofilter

RO

RO reject(processed in another loop)

pure water (RO pass)and Gd2(SO4)3 Return to tank

Water withGd2(SO4)3 from the tank

Gd2(SO4)3 (NF reject)

Concept of the water circulation system

Gd2(SO4)3 and UF passed water (UF pass)

Small size contaminants(NF pass)

Reject large size contaminants(UF reject)

31

Page 32: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Reactor Neutrino at GADZSOOKS!

w/o oscillation

w/ oscillation

MeV

With / without oscillation

10 years’ sensitivity

sin2(2θ)

Δm

2 (10

-4 e

V)

Number of events at SK per year(~3000 /year)

Current solar+KamLAND error size

Sensitivity of parameter measurement( 10 years)

very preliminary 95%CL

Page 33: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

400 kg 88%

274 kg 83%

149.4 kg 73%

89.4 kg 62%

60 kg 52%

30 kg of Gd2(SO4)3 8H2O

in 200 tons 35% captureon gadolinium

Cap

ture

s on

Gd

Gd in Water

0.0001% 0.001% 0.01% 0.1% 1%

100%

80%

60%

40%

20%

0%

Thermal neutron capture cross

section (barns)

Gd = 49700

S = 0.53

H = 0.33

O = 0.0002

2013/6/14 33RENO 50

M. Vagins

Page 34: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

[Yano-san]2013/6/14 34RENO 50

Page 35: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

[Yano-san]2013/6/14 35RENO 50

Page 36: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

[Yano-san]2013/6/14 36RENO 50

Page 37: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Gd Recovery SystemR&D at UCI

2013/6/14 RENO 50 37

Page 38: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Y. Takeuchi, ICRR

M.Smy, “Low Energy Requirements for the GADZOOKS! Project”,SK meeting, Dec.3, 2006

382013/6/14 RENO 50

Page 39: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Epoxy Testpaint on welded part of the SUS tank

BIO-SEAL 197 BIO-DUR 560

39

M20 bolts in a flange apply epoxy w/o welding.

Epoxy paints on the base of bolt.2013/6/14 RENO 50

Page 40: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Epoxy TestPressure vessel

The test flanges are put on both sides and give pressure to the vessel.

Pressure test (0 5kg/cm2) was done on Oct.19, 2011.No leak and no pressure drop.

Pressure cycle (0 5kg/cm2) test was done on Oct.20-27.No leak and no pressure drop.

Long term stability test is running from Oct.28 for 3 months and no problem was found.

Successful

402013/6/14 RENO 50

Page 41: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Possibility of Acrylic Vesseladditional layer of protection

Basic idea: extend the frame above the PMTs and put thin acrylic plates.

Outer detector

Inner detector

Acrylic vessel

Gd-loaded water

412013/6/14 RENO 50

Page 42: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

This apparatus deployed in the SK tank.

BGO

13 cm

18 cm 1

8 cm

5 c

m

BGO

0.2 % GdCl3Solution

Am/Be

GdCl3 test vesselTest Cherenkov emission of Gd(n,g)Gd

α + 9Be → 12C* + n 12C* → 12C + g(4.4 MeV) n + p → …… → n + Gd → Gd + g (totally 8 MeV)

BGO signal (prompt signal (large and long time pulse))

Look for Cherenkov signal (delayed signal)

Page 43: Future SK Program for e Physics Atsuko Kibayashi For the Super-Kamiokande Collaboration Okayama University June 14, 2013 1 RENO 50 2013/6/14.

Cherenkov signal of Gd gamma rays

0

Time from prompt

100ms

Vertex position92% within 2m

dR [cm]

Energy spectrum

Measured time, vertex and energy distributions are as expected from the MC simulation.

Astropart. Phys. 31, 320-328 (2009)arXiv:0811.0735