Super-XENON
Liquid Xenon Dual Phase
20 ton Detector
International effort
between USA, Europe and Japan
with US Leadership:
Elena Aprile (Columbia)
Katsushi Arisaka, David Cline,
Hanguo Wang (UCLA)
Uwe Oberlack (Rice)
4/24/08
Katsushi Arisaka, UCLA
1
Outline
Evolution from Xenon100 to Super-Xenon
Physics Reach
Detector Concept
Super-XENON (20 ton Xenon Detector)
QUPID (Quartz Photon Intensifying Detector)
Estimate of Backgrounds
Cost, Schedule
Specific Needs for S4
Uncertainties and necessary R&D
Project Engineering/Development needs from S4
4/24/08
Katsushi Arisaka, UCLA
2
Evolution from XENON100
to Super-XENON
4/24/08
Katsushi Arisaka, UCLA
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XENON100/1Ton Collaboration
DOE + NSF
NSF
NSF
Switzerland
Katsushi Arisaka
David Cline
Hanguo Wang
UCLA
4/24/08
Portugal
Italy
h
Katsushi Arisaka, UCLA
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Comparison of Detector Size
Super-XENON
20 ton
(10 ton)
XENON1T
2.4 ton
(1 ton)
LUX
ZEPLIN-II
31 kg
(7.2 kg)
XENON10 XENON100
30 cm
4/24/08
170 kg
(50 kg)
14 kg
(5.4 kg)
15 cm
14cm
20 cm
300 kg
(100 kg)
2m
1m
65 cm
30 cm
30 cm
43 cm
1m
Katsushi Arisaka, UCLA
2m
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WIMP Cross Section (Log of cm2)
Projected Sensitivity (90% CL) vs. Year
(for WIMP Mass = 100 GeV)
ZEPLIN-II
XENON10
XENON100
LUX
XENON1T
Super-XENON
Year
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Katsushi Arisaka, UCLA
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90% CL Sensitivity to the Cross Section
(one year, background free)
5-30 keVr
40-130 keVr
XENON10
Xe(100 kg)
Ar(1 ton)
Xe(1 ton)
Ar(10 ton)
Xe(10 ton)
Ar(100 ton)
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XENON100 (construction nearly completed)
Bell
Grids
Structure
170 kg LXe (vs. 20 kg in
XENON10)
50 kg fiducial mass (vs.
5 kg in XENON10).
x10 fiducial mass
242 R8520 PMTs with
lower background and
higher QE (vs. 89 in
XENON10)
lower background
stainless steel cryostat
and inner chamber
a factor of 100 lower
background
Top PMTs
Teflon
Panels with
HV
Racetracks
Active LXe Target
Active LXe Shield
Bottom PMTs
Cathode Mesh
Shield PMTs
Vacuum Cryostat
8
XENON100: the TPC Assembly
9
XENON1T (Proposal in September 2008)
Liquid Xe (2.4 ton
Radiation- free
Photon Detector
(3” QUPID, Total 968)
1m
PTFE Spacer
OFHC (Oxygen-Free
High Conductivity Coppe
Vacuum Vessel
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Super-XENON
Detector Concept
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Super-XENON
Liquid Xe (20 ton)
Field Shaping Wire
Radiation- free
Photon Detector
(3” QUPID, Total 3950)
2m
OFHC (Oxygen-Free
High Conductivity Copper)
Vacuum Vessel
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Concept of Super-XENON
0V
Gas Xe
Anode Wire
-10 kV
-17.5 kV
2m
-10 kV
Electron
Trajectories
5 cm
20 cm
Double-Layer
Field Shaping Wires
(XENON100 - like)
Radiation-free
Photon Detectors
(QUPID)
+Pt Coating
175 nm
Liquid Xe (20 ton)
Fiducial Volume (10 ton)
-200 kV
-10 kV
Cathode Wires
2m
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Acrylic Vessel based Super-XENON
(Compatible with DEAP/CLEAN, WARP, XMASS…)
Acrylic Sheet
+ ITO Coating
+ TPB Coating
0V
-10 kV
Gas Xe/Ar
-17.5 kV
TPB Coating
+ATO Coating
+ Acrylic Sheet
+ITO Coating
-10 kV
Electron
Trajectories
2m
20 cm
Radiation-free
Photon Detectors
(QUPID)
175 nm
125 nm
Liquid Xe (20 ton), Ar (9 ton)
430 nm
Fiducial Volume (Xe 10 ton, Ar 5 ton)
-200 kV
-10 kV
2m
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Katsushi Arisaka, UCLA
TPB Coating
+ ITO Coating
Acrylic Sheet
+ ITO Coating
14
Equipotential lines and Electron Trajectories
ITO (Indium Tin Oxide
Transparent Conducti
Coating (~1 k⁄ )
ATO (Antimony Tin Ox
Transparent Resistive
Coating (~1 G⁄ )
Electron
Trajectories
ITO (Indium Tin Oxide
Transparent Conducti
Coating (~1 k⁄ )
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Expected No. of Photoelectrons per keV
(Abs. Length = 10 m, Scat. Length = 50 cm)
PTFE on Side Wall (Reflectivity = 98%)
Photon Detectors on Side Wall
~ 1.5 pe/keV
4/24/08
~ 3 pe/keV
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QUPID
(Quartz Photon Intensifying Detector)
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QUPID (Quartz Photon Intensifying Detector)
Photo Cathode
(-10 kV)
Quartz
APD (0 V)
3 inch diameter
4/24/08
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13 inch HAPD and PE Distribution
Developed by Hamamatsu for T2K and other neutrino experiments.
1 pe
2 pe
3 pe
4 pe
5 pe
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Comparison of Low-radioactive
Photon Detectors from Hamamatsu
R8520
1 inch
XENON10
4/24/08
XENON100
R8778
2 inch
XMASS
Katsushi
LUXArisaka, UCLA
QUPID
3 inch
XENON1T
Super-XENON
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Comparison
Unit
R8520
1 inch
Square
R8778
2 inch
Round
QUPID
3 inch
Round
mm
mm
cm2
cm2
%
25.7 mm square
21.8 mm square
6.60
4.75
72.0%
57 mm diameter
45 mm diameter
25.52
15.90
62.3%
70 mm diameter
65 mm diameter
38.48
33.18
86.2%
1.51
2.09
1.38
$1,100
$231
$2,700
$170
$3,000
$90
1.11
0.53
25%
35%
1.3
1.3
16%
25%
35%
2.5
1.1
23%
30%
35%
5
1
30%
1.20
1.00
2.00
0.91
1.32
1
0.2
0.2
0.03
50
10
3.1
0.4
1.000
0.100
0.030
0.003
0.020
0.010
0.010
0.008
Size
Shape
QUPID/R8778
Dimension
Outer Size
Photo Cathode
Total Area
Photocathode Area
Filling factor
Price
Price
$
Price per potocathode area $/cm2
Performance
QE at 175 nm (Typical)
%
QE at 175 nm (Best)
%
Peak to Vally Ratio
ENF
DQE = QE/ENF (Typical)
%
Radioactivity
Total (Typical)
mBq
Total (Best)
mBq
Per area (Typical) mBq/cm2
Per area (Best) mBq/cm2
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Expected Performance of QUPID
Large diameter:
3 inch
Existing largest PMT with low radioactivity is 2 inch (R8778)
Extremely low radioactivity:
To be compared with
<< 1 mBq
• Hamamatsu R8778 (2 inch) for XMASS:
• Hamamatsu R8520 (1 inch) for XENON100:
~10 mBq
~1 mBq
True photon counting
1, 2 … 5 photo-electron peaks are clearly visible.
Collection efficiency is ~100%
Simple HV supply
HV supply can be common for all HAPD
• No tube to tube variation of gains
Resister chain not necessary
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WIMP Energy Spectrum
and Sensitivity
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Gamma Backgrounds after S2/S1 cut
(1 mBq / QUPID, 2m Xenon Detector)
BG (0 cm shield)
100 GeV WIMP (10-44 cm2)
BG (5 cm shield)
1 TeV
2 DBD (1022 yrs)
pp Solar Neutrino
BG (10 cm shield)
10 TeV
Be7 Solar Neutrino
4/24/08
Katsushi Arisaka, UCLA
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Expected Background from Gammas
(1 mBq / QUPID, 1 year, Multi Hit Cut, No S2/S1 cut)
Xenon (2m)
0.01 /10ton-year
after S2/S1 cut
< 10–8 DRU
10 ton
XENON1
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Katsushi Arisaka, UCLA
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Neutron Backgrounds after Multi-hit Cut
(1 n/year/QUPID, 2m Xenon Detector)
100 GeV WIMP (10-44 cm2)
1 TeV
10 TeV
0 cm
20 cm
10 cm
30 cm
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Expected Background from Neutrons
(1 n/year/QUPID, 10 year, No Multi Hit Cut)
Xenon (2m)
10 ton
4/24/08
Katsushi Arisaka
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Expected Background from Neutrons
(1 n/year/QUPID, 10 year, Multi Hit Cut)
Xenon (2m)
0.4 n /10ton-year
< 10–8 DRU
10 ton
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Expected No. of WIMP Signals and Backgrounds
(10 ton-year of Liquid Xenon, Window = 3 – 15 keVee)
No. of Background Events
No. of WIMP Signals
10-44 cm2
Gamma
(no cut)
10-45 cm2
Gamma
(S2/S1 cut)
10-46 cm2
Neutron (no cut)
10-47 cm2
pp-chain Solar
Neutron
(multi-hit cut)
10-48 cm2
2-Neutrino DBD
19.2 ton
14.0 ton
9.8 ton
Self Shielding Cut (cm from wall)
4/24/08
Katsushi Arisaka, UCLA
WIMP Mass (GeV)
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Summary of WIMP Detection
Sensitivity:
Background:
< 10-47 cm2 at 100 GeV WIMP mass. (< 10-46 cm2 at 1 TeV)
Completely free from external gamma ray backgrounds.
• < 10 mBq / PMT
– QUPID is < 1 mBq (Goal is < 0.1 mBq)
• 10 cm active shielding
• S2/S1 cut
Neutrons background is negligible too.
• < 1 neutron / year / PMT required.
– QUPID goal is < 0.1 n/year (Current R8778 is < 5 n/year)
Irreducible background comes from pp-chain solar neutrino.
• ~10-7 /kg/keV/day ~0.5 event /ton/year (in 3-15 keVee window)
– Assuming 99% rejection by S2/S1 cut.
Still investigating other backgrounds
• Internal Krypton and Radon in Xenon
Photon Detection:
Complete surface coverage by QUPID ensures > 3 pe/keV.
4/24/08
Katsushi Arisaka, UCLA
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Cost Estimate
& Schedule
4/24/08
Katsushi Arisaka, UCLA
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Cost Estimate of Super-XENON
Liquid Xenon Detector (2 m x 2 m)
Liquid Xenon
Detector
Photon Detector & Readout System
3" QUPID
Readout (Amp+FADC+FPGA)
DAQ System
Facility
Cryogenic System
Purification System
Safety and Recovery System
Low Background Counting
Water Tank Veto (12 m x 12 m)
Water Tank
Purification System
PMT + Readout
Unit Price
No. of Unit
Total ($M)
$2M /ton
20
40
5
$3,000
$400
4,000
8,000
12
3.2
0.8
Total (with 20% contingency)
4/24/08
1
1
1
2
2
1
2
71 (85)
Katsushi Arisaka
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Cost (in $M) & Schedule
Agency Total FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14
Pre DUSEL
XENON100
Total US
DOE
NSF
Foreign
1
0
1
0.3
0.3
0.7
0.3
0.1
0.7
0.2
XENON1Ton
Total US
DOE
NSF
Foreign
10
5
5
5
4
2
2
2
4
2
2
2
2
1
1
1
50
25
25
35
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
DUSEL (4850 ft)
Super-XENON
Total US
DOE
DUSEL
Foreign
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10
10
15
20
10
10
15
9.1
5
4.1
4.1
33
Specific Need for S4
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Uncertainties and Necessary R&D
Experience from XENON100 – This summer
Purification of Xenon (for long electron life time)
Kr removal by Distillation Tower
Optical property
• Absorption Length of Xenon
• Reflectivity of PTFE
Development of QUPID – This summer
Basic functionality as photon detector
Operation under Liquid Xenon temperature
Radiation Counting (at Gran Sasso)
Optimization of Active veto
Water Cherenkov detector (Gd doped?)
Liquid Scintillator
4/24/08
Katsushi Arisaka, UCLA
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Project Engineering/Development
and needs from S4
Active Veto system
Mechanical structure
Purification system
Cryogenic system
Cooling system
Purification system
Safety and recovery system
Electronics & computing infrastructure
Power line
Computer optical link
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