Direct Dark Matter Search - TAUP2019 Toyama 2019/09/11
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Direct Dark Matter Search
Masaki Yamashita
Kamioka Observatory, ICRR
The University of Tokyo
TAUP2019 Toyama
2019/09/11
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 1
Nest of Dark Matter Hunters in the World
Boulby
NaIAD
SNOLAB ZEPLIN I/II/III
DEAP DRIFT I/II
CLEAN
PICO
NEWS-G
Frejus YangYang
EDELWEISS KIMS, COSINE
Soudan Kamioka
CDMS II CanFranc Gran Sasso XMASS
CoGENT IGEX DAMA/LIBRA NEWAGE
ROSEBUD CRESST PICOLON
JINPING
ANAIS XENON
PANDA-X
ArDM DarkSide
CDEX
NEWS
Masaki Yamashita
South Pole
DM-Ice
Kamioka Observatory, ICRR, The University of Tokyo Masaki Yamashita
Detector Active Mass [kg]
1000
1 kg
0.01
100
0.1
10
LAr
This talk LXe
Cryogenics
Tom Shutt New Technology ?
Susana Low Mass
Cebrian
Directionality NaI
Bubble
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 3
Contents
• What will we get from direct detection?
•Current status
– cryogenics detector for low mass WIMP
– liquid rare gas detector for high mass WIMP
•Challenge for G2 (~5 tonne , 2019- )
–Rn emanation in the detector
–LXe purification
–Neutron veto
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 4
Elastically scattering target nuclei
Dark Matter
（WIMP）
Deposit Energy
v ~ 200 km/s
• WIMP mean velocity is about 230 km/s at the location of our solar system.
• WIMPs interact with ordinary matter through elastic scattering on nuclei.
• As the velocity of scattered nuclei is non-relativistic, no more Bethe-Bloch
energy loss but Lindhard for scintillator and ionization detectors.
• Typical nuclear recoil energies are of order of 1 to 100 keV.
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 5
Differential Rate (WIMP case)
Expected spectrum:
dR R0 F 2 (ER ) k0 1 ! vmax 1 3
dER
= E0 r k 2πv0 vmin v
f (v, vE )d v
R0: Event rate F: Form Factor motion dynamics => annual modulation
(depends on atomic
Maxwellian distribution for DM velocity
nuclei）
is assumed.
V :velocity onto target,
VE: Earth’s motion around the Sun
Spin independent Spin dependent
2
2 µT (λ2N,Z J(J+1))Nuclear µ2
σ0 = A µ2 σχ−p σ0 = T
(λ2p,Z J(J+1))proton µ2p
σχ−p
p
Kamioka Observatory, ICRR, The University of Tokyo Masaki Yamashita 6
Differential Rate
5GeV Mass 100GeV Mass
Xe
I
Ge
Na
Xe Ge Na
I
low energy threshold Large Mass Target
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 7
of the existing experiment, with the exception of the central TPC, mature
We have studied the reconstruction
are designed of toWIMP properties,
accommodate namelytarget
the larger massmass
and [83].
scattering
The energy
What we get from Direct Detection?
cross section, from the measured recoil spectra.
DarkSide
3.3 t as activeand
realistic detector parameters, backgrounds
In a plans
collaboration
target
numerical model,
a 5 t LAr
mass, in the uncertainties
astrophysical
we have
dual-phase
existing neutron
incorporated
detector,
andOur
[42]. muon
with
veto
primary
atomic
est bac
47
once we detect dark matter….
at LNGS. The aimed
study was directed towards spin-independent cm2 [96]. however, given
sensitivity is 10 interactions;
WIMP-nucleon perime
• DM particles
DARWIN’s are moving
excellent toDARk
around
sensitivity us.matter WImpinteractions,
spin-dependent search with Noble liquids for
especially (DARWIN) is an it
129 Xe [51], is rathe
initiative to build an ultimate, multi-ton dark matter detector at have re
can be extended to
• Mass of DM particles axial vector couplings as well. Figure 3 (left) shows the reconstructed
LNGS [97,93]. Its primary goal is to probe the spin-independent in the d
parameters for three hypothetical particle masses and a Complementarity
fixed cross
WIMP–nucleon cross section down to the 10 section 49of 2 2⇥of
10 targets
47 cm2 ,
cm region for tronic a
• DM-nucleus scattering
assuming an exposures of 200 t⇥y cross section
⇠50 [42].
GeV/c 2The corresponding
WIMPs, as shown in number of events
Fig. 3. It would thus are 154,the
explore 224 constru
and
• It 60, for WIMP
will rely on ρdm (masses of experimentally
= 0.3 GeV/cm20 GeV/c 2 , 100 GeV/c2 and 500 GeV/c2 , respectively. Us-
3), Velocity distribution
accessible (= >space,
parameter Maxwellian, DMbestream?
which will finally ) orders
ing the same exposure, Figurelimited by irreducible
3 (right) shows theneutrino backgrounds.
reconstructed mass Should WIMPs
and cross be
section will sta
Xe target
20GeV 100GeV 500GeV Xe
154 evts 224 evts 60 evts
neutrino floor Xe + Ar
Figure 3. The 1 and 2 credible regions of the marginal posterior probabilities for simulations of
WIMP signals assuming
J. Aalbers various masses
Fig. 4. and
et al JCAP11(2016)017 spin-independent
The 1- (scalar)
and 2- credible regions cross
J. Newstead
of the etsections
al , PRD
marginal with
88,
posterior DARWIN’s
076011 (2013)for simulations o
probabilities
LXe target. The width and length of these
WIMP contours
parameters demonstrate
can be reconstructed for how well
different the WIMP
exposures of a LXeparameters
or LAr detector. The ‘+’ in
can be Observatory,
reconstructed ICRR,
in DARWIN 20 t ⇥ yraLXe
after 200(red),
t⇥y and 10 t ⇥ yr LXe
exposure. plus‘⇥’
The 20 t ⇥ Ar (blue). the
indicate (Right) 10 t ⇥ yr LXe
simulated plus 20 t ⇥ yr LAr
bench-
Kamioka The University of
48 Tokyo,
2
and 3 ⇥ 10 Masaki Yamashita
cm (blue) (For interpretation of the references 2to colour in this 2
figure legend, the r
8
temperature in the operating point and to inject pulses which are needed for the energy calibration.
The experiment is based in the LNGS (Laboratori Nazionali del Gran Sasso) underground laborator
Low Mass by cryogenic detectors
central Italy.
2. CRESST-III Detectors
The results from CRESST-II Phase 2 [3, 4] clearly demonstrate that the energy threshold is the m
EDELWEISS SuperCDMS CRESST-III
driver for low-mass dark matter search. Given the kinematics of coherent, elastic dark matter parti
nucleus scattering, extremely low thresholds of O(50 eV) are necessary to access dark matter part
masses of O(0.1 GeV). CDMSlite
CaWO4 @LNGS
Therefore, the detector optimization for CRESST-III followed a straight-forw
LSM (Modane)
approach thoroughly E threshold
discussed in = 56The
[5]. Mass:
eV CaWO4 target crystals of 23.6 g available quality
already
total 20 kg Ge
radiopurity and optical properties) have been scaled down in E threshold
mass from ⇠= 30030.1geV
to 24 g and
thermometer design has=> SNOLAB
been optimised to achieve a threshold ofDetector Mass :
Area ∝ Active Mass
cryogenics
CRESST
CDMS ΣAr
EDELWEISS …. DS-50 ΣXe
LUX
DEAP3600 Panda
XENON1T
XMASS
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 10Low Mass by cryogenics detectors
and legend
responds to
tal achievin
ogy [17].
EDELWEISS
The impr
DAMIC in the resp
CDMSlite for CRESS
CRESST-III
NEWS-G more than
0.16 GeV/c
factor of 6
range (0.5-
leading lim
DarkSide
arXiv:1901.03588v2
In this p
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita ing method 11Mig FIG. 5. Upper limits on the SI-LM DM-nuc
LDM-nucleon c
29 dal
Low Mass by cryogenics detectors
10 tion cross-sections at 90% C.L. using signal mo
Mig 4
dal
CRESST-Li (proton) S1-S2 data (XENON1T)
Migdal e↵ect and BREM in the XENON1T exp
10 32 the S1-S2 data (blue
CDMSLite (proton) S2-only data (XENON1T)
enhancement in single-electron emission [22], we utilize a Mean energy in flat solid lines)[keV
ER spectrum and
ee ]
S2-only dat
lines).
0.15 Green
0.2 and yellow
0.3 0.5 shaded
0.7 1 regions 2 3give the
10 23
29
combined p-value cut [23] against events close in time or
III.Spin-independent
I. Spin-dependent and legend of figu
10 reconstructed position to recent high-energy events, with sitivity contours for the S1-S2 data, respectivel
Events / (tonne ⇥ day ⇥ keVee )
20 GeV/c2 responds to across
surf
(neutron-only)
XENON1T
80% efficiency, as determined with S1-tagged cathode 10limits
3
on4 GeV/c
the 2SI DM-nucleon interaction
26 BRE
10
10 32 events and M
BREshown in purple in Figure 2. This last cut LUX [26] and XENON1T S2-only tal achieving
(elastic NRa thr
re
XENON1T
M
only helps against the single-electron pileup background, 102
Mig
daapply
BRE
M
also shown. ogy [17].
35 so Mwe
i l it only for S2 < 200 PE. B
discovery mode
29 gda RE
10 We lexclude events in which
M
EDELWEISS
by a merged S1, with ⇠ 95% efficiency,
Mi the S2 waveform
gda
l
is distorted
as determined with
101
Cathode The improveme
10 38
10 32
CDEX (BREM)
220
Rn [24] and neutron LUX (Migdal)
generator data. MigTo remove double
dal 10DM-nucleon
0
in the respectively
interaction cross-section using
LDM-nucleon cross section s [cm2]
CRESST-Li (neutron)
EDELWEISS (Migdal) NEWS-G
scatters, we apply theS1-S2 same cut to events with substantial
the Migdal e↵ectfor CRESST-II to
CEvNS
41
CRESST-O
CDEX
secondary
(Migdal)(neutron)
S2s as in [5,
data (XENON1T) S2-only data (XENON1T)
CDMSlite
15], with 99.5% efficiency. CDMSlite els from and BREM with
10 35 CDMSLite
CRESST-III (neutron) S2-only data
DarkSide (XENON1T) S1-S2 data (XENON1T) 10 1
2 2 Flat ER
10
0.06
Finally, we apply two cuts specifically to events with S1s.
0.1 0.2 10 1
0.5 1.0 100
2
60 MeV/c
90 120 150 200
to 2 GeV/c
500
, more
and
1000
than
Fig. three
5 shows
3000
i
t
Events whose drift time indicates a2 z outside II. Spin-dependent
[ 95, 7] cm upper limits on the SI-LM DM-nucleon
0.16 GeV/c 2 . inter
At 0
are removed, to exclude mCRESST-III
c [GeV/c
events high ] in the (proton-only)
detector and
S2 [PE]
2
10 23 section with masses from 60 MeV/c
(black dots);to 5 G
S1-tagged cathode events. We conservatively assume no FIG. 4. Distribution of events that pass
factor
all cuts
of 6(30) co
Migdaldetector
effect:response M. Ibe et outside
at all al. JHEP this z03, region194 (2018). upper limits derived using the S1-S2 data
to avoid error bars show statistical uncertainties (1 Poisson). The
FIG. 4.26 Upper
10
limits
assumptions BRE on the SI (upper panel), SD proton- thick black line shows the predetermined summed
Mon the low-energy LXe light yield. We also the median sensitivity by range
about (0.5-1.8)
background
1-2 due Get
model, below which its three components are indicated, with
only (middleremove
panel),events and with SD neutron-only
a very large RS1 B
EM(lower
(> 200 panel)PE), with DM- colors as in Fig. 3. The lightly shaded orange
fluctuation of the ER leading
background (purple)limit
in from
his-the lo
nucleon interaction
negligible
Mig
dal cross-sections
efficiency loss. at 90% C.L. using signal togram,FIG.stacked5. on Upper
the total limits on
background, the
shows SI-LM
the DM-nuc
signal
29
10 Detector
models from the Migdal response.—We
e↵ect andcompute BREM XENON1T’s
in the response
XENON1T modelgion.
tion The
GeV/c 2
for 4 cross-sections
(20results,
GeV/c2at by
) SI90%DM searching
models
C.L. forsignal
excluded
using ER sig
at mo
DarkSide
experiment with
32
CRESST-Li
space used
S1-S2
(proton)
for the
Two phase noble gas (Ar,Xe) detectors were
to ERs and NRs in the same two-dimensional
the data (blue
S1-S2 data (XENON1T)
efficiencies and
Mig
solid
project
dal
lines)
the model
(S2,
and z)
after
S2-
exactly
for
by
these
90%
Migdal
confidence
the e↵ect
analyses,
Migdal
and
level.
and
the
e↵ect,
dashed
The
BREM
arrows
give
line in
the
show
the
the
S2
the
threshold,
ROIs
best constrain
XENON1T as exp
only10data (black
CDMSLite solid
(proton)lines).
efficienciesS2-only Green
S2 forand
data (XENON1T) yellow with shaded proton-only,
the S1-S2 dataSD (blue neutron-only,
solid lines) and
data.re- in Figures 2-3. All rates are shown relative to the e↵ective
and SI-LM
S2-only dat
gions give
10 23
applying
the
We 1 and
use the best-fit achieved competitive or better results by S2 only
2 sensitivity
onto
detector response
comparison
contoursmodel for the
from [21], S1-S2 remaining
but the
lines).
mean
exposure
interaction Green
expected
after
energy
and selections.
of events
The top x-axis
yellow shaded
cross-section after
for
cuts
regions
mass
for a
shows
flat
give the
below
ER
ab
data, respectively.
assume that TheNRs upper
belowlimits
0.7 keVon andthe III. Spin-dependent
ERsSIbelow DM-nucleon
186 eV sitivity contours for the
2 S1-S2 data, as respectivel
2.0, and 4.0 GeV/c , respectively compa
26
(⇠ 12 produced
interaction cross sections electrons) analysis in this region.
from LUX are undetectable,
(neutron-only)
[26], EDELWEISS as the LXe [27],
spectrum
limits
ous
if there were
experiments
no Q
on the SI DM-nucleon
y cuto↵.
[26–34]. In this
interaction
arXiv:1901.03588v2
The upper paper,crossw
limits
CDEX10 [28], charge
CRESST-III yield
BRE Qy has never been measured below these
[29], NEWS-G [30], CDMSLite- LUX [26] and XENON1T S2-only (elastic NR re
II [31], and DarkSide-50
M
See:
energies. Even without these cuto↵s, the low-energy Qy
[32], and upper limits on the SD
the
also
S1-S2
shown.
data become comparable
DM models.— We constrain several2DM models, us-
ing methods, with featu
th
29
from
Mig [21] is significantly lower than Bthat
al FIG. 7. Experimental R
results
favored by other
on elastic, S2-only
spin-independent data dark ⇠ GeV/c
atenergy
mat- nique
since for software
thecon-efficienc
10
DM-nucleon
and CDMSLite
d
interaction cross
New Idea in conventional detector by Tom Shutt
sections
LXe measurements [11, 12] and models [25]. Thus, our
[34] are also shown. Note
from EMCRESST
that the upper
[29, 33] ing [28]
sider S2
to compute
data to dark
the
DM signals
spectra.
with
allows
First,
mass
we
one of ⇠ mak
to GeV
results ter
shouldnucleus scattering
be considered depicted
conservative. in thelimits
cross-section versus
spin-independent (SI) mat-
and spin-dependent (SD) DM-
derived
10 32using CRESST-Li
unbinned
the
WhileS1-S2
channel
profile
ter a complete
is
particle
(neutron)
likelihood
DM2: DarkSide-50 talk by Sandro De Cecco
and model
unavailable,
S2-only
mass
method we
plane.
can
dataIf
of backgrounds
[16]
Mare
quantify
and
not
igd
al
inferred
in
specified
three
simple
using
the S2-only
compo-
nucleus
explicitly,
Poisson etc...)
sufficiently
scattering with
DM-nucleon
results
and are
particle
high.
reported
physics
However,
the same
interaction
models (form
the upper
astrophysical
cross-section
best factors,
(v0 , vesclimits
detector struc-
,
using
opera
Kamioka Observatory, with ICRR, The data University of Tokyo,and Masaki the
Yamashita
els S1-S2
thisfrom the data Migdal do not
e↵ect provide
and BREM significantly
with
the 90 % confidence level in (C.L.).
Figures 3The result
tureof work is[5,depicted
CRESST-O (neutron) S1-S2 (XENON1T)
nents of background, illustrated functions) as 6]. For SD 02/2018)
scattering, achieves
we con- 12Liquid Rare Gas
Boiling Point ionization scintillation
Z(A) Density [g/cm3]
at 1 atm [K] [ e-/keV] [photon/keV]
Ar 18(40) 87.3 1.40 42 40
Xe 54(131) 165 3.06 64 46
LXe (-100℃）
• Large Mass ( ~5 tonne or more active mass)
• Purification gas/liquid phase
• Online purification (getter ,distillation for both
electro-negative and radio-impurity)
• No long-half life radio isotope for Xe
except 136Xe (double beta decay), 124Xe (double
electron capture)
Neutrino#5 :Christian Wittweg talk
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 13Single phase liquid noble gas detector
• Simple design, large mass
• 4π photo coverage; XMASS 14.7PE/keVee
• Strong pulse shape discrimination; DEAP 2.7x108 44-89 keVee
uction Milestones
SNOLAB in Canada Kamioka in Japan
or
June
n July
014
DEAP3600 XMASS-I
3279kg LAr 832 kg LXe
DM13: Shawn Westerdale DM8: Kazufumi Sato (Hidden Photon search)
Today Mark Boulay DM13:Takumi Suzuki (Inelastic search)
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 14matter (DM) detector
Dual Phase TPC (Ar, Xe)
• two signals for each event:
• Energy from S1 and S2 area
High density, self-shielding
• 3D event imaging: x-y (S2) and
z (drift time) 1. Scintillation & Ionization signals
2. 3D position
• self-shielding, surface event
rejection, single vs multiple 3. ER/NR discrimination, PSD (39Ar)
scatter identification 4. Multiple scatter rejection
• Recoil type discrimination from 5. Scalable to multi-ton
ratio of charge (S2) to light (S1)
background-like (β, γ)
LAr
signal-like (WIMP)
S2
Powerful particle ID ( ~ 99.5%)
Kamioka Observatory, ICRR,
S1The University of2 Tokyo, Masaki Yamashita 15Current status
Liquid Xenon
Liquid Xenon TPCs TPCs
Phys.Rev.Lett. 121 (2018) no.11, 111302
10 ZEPLIN-III XENON100 LUX PANDAX-II XENON1T
XENON100 LUX PANDAX-II XENON1T
XENON1T
LUX PandaX-II @Gran Sasso
@Jinping, China Italy
@Sanford, US 580 kg (100 kg) 2 tonne
370 kg (100 kg) (1.3tonne)
DM13: today DM2:
Vitaly Kudryavtsev Xiaopeng Zhou
12kg
kg 62250
kg kg 250580
kg kg 580 kg
2,000 kg 2,000 kg
62
(7 Observatory,
Kamioka kg) (34 kg) The
ICRR, (100 kg) (362 kg) (1,042 kg)
(34 kg) (100 kg) University of Tokyo,
(362 kg) Masaki(1,042
Yamashita
kg) 16!!!"CL
our factor ~10 increased exposure, known cut efficiencies, and resolution uncertainty,
ALP/Hidden Photon
include a Gaussian “rare event” signal peak, and compute the upper limit (90% CL): 10-11
Ae
(ALPs) mo.
g
r a na De
Majo XENON100
PRELIMINARY
10-12
prev. work
LUX
-13 PandaX-II
10
ALPs & dark photons limits XMASS
this work
n Best Ge-based limitsFuture experiments Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 18
PandaX-xT facilities
Generation 2 experiment 2019-2025
active mass about 4-7 ton will start commissioning soon. 512
LZ Design
• 10 t liquid Xenon
(7 t active, 5.6 t fid.Vol.)
• 494 3” PMTs
• 50 kV cathode Current Status and Schedule
• Xenon skin detector
(131 1” & 2” PMTs) • R&D work-in-progress
• liquid scintillator outer • 2019-2020: assembly and commissioning
3 t )
detector (120 8” PMTs)
t ) K ( 2
PLIN Dark Matter Experiment .9t ) ( 4 20
V
high purity water shield
I -
•
t )
Status update - PMT arraysnT
Technical Design Report, arXiv:1703.09144 ( 5
a X -
S i de
7
4850L Sanford Lab
d rkCooling bus
•
LZ 0 -( O N a n - a
N P D 2-
Markus Horn - LUX-ZEPLIN Dark Matter experiment 7
0 2 XE - Inner2 0 2
FIG. 4. 3D schematics of the DarkSide-20k experiment. The drawing shows the
2 0 19 2 0 stage:
• Intermediate
vessel
20 TPC Drift re
surrounded by the VETO detector made of Gd-loaded PMMA shell sandwiched betw
inner one, named IAB and the outer one, named OAB in the text), all contained in
2 Krypton
The OAB is optically separated by the AAr in contact with the
are yet to be defined.
cryostatmeasureme
wall by a m
• PandaX-4T (4-ton
lower bias voltage.in sensitive
SiPMs can also beregion) with SI
efficiently integrated intosensitivity
tiles that cover l
radiopurity up to an order of magnitude than PMTs.
• On-site assembly
Utilization ofand commissioning:
TPC prototype
ProtoDUNE 2019-2020
cryostat: The decision to abandon an organ
to host DS-20k within a ProtoDUNE-like cryostat was originally motivated by
environmental impact on underground LNGS operations but carries significa
2018/7/24 Yong Yang, SJTU
! M. Kapust Indeed, operating the TPC directly in the ProtoDUNE-like cryostat allows e
cryostat and placing SiPMs modules outside the TPC, thus keeping most rad
• Top & Bottom array checkouts complete - June ‘19 away from the active volume. Also, the scalability to even larger experiment is
Markus Horn - LUX-ZEPLIN Dark Matter experiment 14
PMT test Ning Zhou, ICHEP 2018 DAQ board
DM18: Jianglai Liu on Today
DM2: Alden Fan DM2: Auke Colijn V. DARKSIDE-20K
DM13: Yi Wang
Thursday
Kamioka Observatory, ICRR, The University of Tokyo, Masakitwo
Yamashita
DS-20k will be located in the Hall-C of the Gran Sasso National Laboratory (
19
detectors: the inner detector and the veto detector, both hosted in a ProtoG2 ΣAr
DS20K (23t) G2 ΣXe
LZ(7t)
ΣAr PandaII-4(4t)
DS-50 ΣXe XENONnT(5.9t)
DEAP3600 LUX
Panda
cryogenics XENON1T
XMASS
CRESST
CDMS
EDELWEISS ….
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 20Today
G3 Ar DM13: Yi Wang G3 Xe
ARGO(300t) DARWIN(40t)
tomorrow
DM18: Carla Macolino
G2 Ar
DS20K (23t) G2 Xe
LZ(7t)
Ar PandaII-4(4t)
DS-50 Xe XENONnT(5.9t)
DEEP3600 LUX
Panda
cryogenics XENON1T
XMASS
CRESST
CDMS
EDELWEISS ….
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 21Challenges for G2 experiment
Target Mass about 4 - 7 ton, starting from 2019-2020
1. emanated Rn background (internal background)
program Phases of the XENON program
2. LXe purification (lifetime for drifted electrons)
3. Neutron veto
ON1T / XENONnT
XENON10 XENON100 XENON1T / XENONnT
1.5 m drift length
~1.5 ms e-lifetime
Rn
Rn
Rn
neutron
2005-2007
13-2018 / 2019-2023 2008-2016 2013-2018 / 2019-2023
cmKamioka Observatory,
drift TPC15
- cm drift
3200 kgTPC ICRR,
– 25kgkgThe 30
/ ~8000 University of Tokyo,
cm drift TPC Masaki
– 161 kg 100Yamashita
cm / 144 cm drift TPC - 3200 kg / ~8000 kg 22Background for G2 experiment (ER)Backgrounds
Background Energy
Before Particle ID Spectrum in inner 1T Physics
3% P
Changes: thinner lines, moved labels,
LZ Preliminary aspect ratio 27% ER
4 69%
10
Total Xenon
Rate [counts/kg/day/keV]
Contaminants ● DR
136 Xe Backgrounds Model - 222/220Rn,
Labor
222Rn
- natKr, fidu
Cosm
• Simulate separate background sources - natAr Source
Background ER (cts) NR (cts)
10 5 - Radioactivity
So->
la
daughter: 214Pb
detector component sources
Detector Components
PMT Structures
9
(See0.027talk
Note:
2.82
theb
0.07
rn TPC Structures 4.44 0.025
- Internal contamination -> expected concentration in xenon Cryostat 1.27 0.018
from1195 dete
Outer Detector 0.62 0.001
External Backgrounds
-
220
Rn signals -> calculated ER/NR spectra
Physics Total:
Surface Contamination ER
40 0.39
Dust (intrinsic activity, 500 ng/cm2) 0.2 0.05
After cuts:
combined5.97 ER
ER
Plate-out (PTFE panels, 50 nBq/cm2) - 0.05
Det.
• Apply + Sur.analysis
WIMP + Env. cuts to simulation results 210Bi mobility (0.1 µBq/kg) 40.0 -
Ion-misreconstruction (50 nBq/cm2) - 0.16
[LZ Projected WIMP sensitivity for 1000 live day
- Single scatters clutter, bu
210Pb (in bulk PTFE, 10 mBq/kg) - 0.12
85Kr
10 6 Laboratory and Cosmogenics 5 0.06
- Energy range -> 1.5-6.5 keVee (ER) or 6-30 keVnr (NR) Laboratory Rock Walls 4.6
A. Kamaha (SUNY A 0.00
- 5.6 tonne fiducial volume
Muon Induced Neutrons
Cosmogenic Activationthe likelih -
0.2
0.06
-
Background Energy Spectrum in inner 1T
0
-
50 100 150
No visible energy in veto detectors within set window
200 Xenon Contaminants 819 0
Internal Backgrounds
222Rn (1.81 !Bq/kg) 681 -
Electronic recoil energy [keV] 220Rn (0.09 !Bq/kg)
natKr (0.015 ppt g/g)
111
24.5
-
-
• Scale results by livetime andChanges:
activities fromthinner
assays lines, moved labels, natAr (0.45 ppb g/g) 2.5 -
NR
LZ: background
LZ Preliminary first dayER discrimination
total counts, with aspect
Physics 322 0.51
10 3 • Combine ratio 136Xe 2νββ
Solar neutrinos (pp+7Be+13N)
67
255
0
0
Alvine Kamaha Diffuse supernova neutrinos 0 0.05
4 • Projected background rates used in profile likelihood
Atmospheric neutrinos 0 0.46
10Amy Cottele Total 1195 1.03
analysis for sensitivity studies
eV]
Total (99.5% ER discrimination, 5.97 0.51
Kamioka
5 Observatory, ICRR, The University of Tokyo, Masaki Yamashita 50% NR efficiency) ●
6.49 DR235.9 ton LXe
= 3 x 1028 atom
1μBq/kg =
3000 222Rn atoms
Rn Rn
Rn
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 24Challenge(1):emanated Rn in LXe
Piston pump
+ online distillation
On line Rn distillation
A. Poster
Molinario
260
Michael Murra
1uBq/kg ~ pp solar neutrino event rate
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 25c" l
iq
Challenge (2) Liquid circulation pu
WIMP-nucleon Cross Section [cm2]
2
XENONnT: Cryogenic LXe Purification (
ins
• LXe Purification
Discussed how such a system could be integrated into XENONnT at last collaboration meeting
10
- 43
li
pu
10
- 44 XENON1T speed
- 45
10
outgas model for nT 2 3 4
10 10 10
Electron Lifetime [µ sec]
c"
•
ionization signal (S2) can be
Side benefit: XENON1T LXe “fast” recovery slowness is solved we have an 80% – 90% eQcient Cu
WIMP-nucleon Cross Section [cm2]
2
ON Collaboration Meeting - Firenze - January 12 - 14, 2018 7 / 16
degraded by the electro-nagative
2019.06.04 Kai Martens, Kavli IPM
impurities such as oxygen. ( < 1 Sensitivity for
WIMP-nucleon σ
ppb) 100 GeV WIMP
10- 47
Recirculation to purify outgas
component:
gas :100 SLPM with SAES getter
liquid : 5L/min=> 2500SLPM
online Purity monitor 10
- 48
10
2
10
3
10
4
20cm drift 102 103
Electrno Lifetime [µ sec]
104
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 26The vessels will be cleaned inside and leak-checked at the fabrication vendor. They will be w
protective sheets at that time, and placed in double bags before being crated for shipping. The
Challenge for G2(3)
sheets will be removed after they are installed in the water tank. The final cleaning of the outs
vessel will be done at that time.
sign
• fission from U/Th and (α,n) reaction(Cryostat, PMT, PTFE)
• 7 neutron/20 ton-year single scatter of neutrons
uter detector scintillator
• irreducible background
• >85% neutron tagging efficiency for DM discovery.
crylic vessels being staged underground in water tank
Figure 4.4.2: Two steps in the assembly sequence. The figure on the left shows one of the
XENONnT LZ
vessels at the point of maximum height above the water tank. The one on the right slow
quadrant vessels in the tank, with one already moved into final location.
ate; As a feasibility study, a mock side vessel was slung under the Yates cage, taken down the
transported to the cart-wash area just outside the LUX experimental hall. We have studied the
installing the acrylic vessels into the LUX/LZ water tank using a detailed computer model. T
vessel will be transported in a horizontal position to the deck immediately above the water t
vessel will then be rotated using lifting eyes at the top and bottom. The left-hand drawing in Fi
nal demonstrates one step of this process, near the point that requires maximum clearance above the
vessel is lowered in vertical position into the water tank and then transported radially outward t
wall of the tank.
The right-hand drawing in Figure 4.4.2 shows the assembly step at which all of the quadrant ves
the tank, and the first one is being brought into place around the cryostat. A white diffuse reflect
is strapped with the foam around the cryostat.
The vessels will be fabricated by Reynolds Polymer Technology of Grand Junction, Colorado. F
will take place during calendar 2017.
4.4.2 PMT Supports
The LAB scintillation light is viewed by 120 8 inch PMTs in a cylindrical array of 20 ladder
PMTs each. Figure 4.4.3 shows the plan view of the PMT support system. The PMT faces are
84 cm from the outer-detector tank wall. The water between the PMTs and the scintillator vessel s
active detector elements from radioactivity in the PMT assemblies. In this location, the PMTs al
Water+0.2% Gd Cherenkov light from cosmic-ray muons passing through the water.
The PMT ladders are attached to the top and bottom of the water tank, at a radius of 282
PMT frame has been adapted from from the Daya Bay desin. A FINEMET magnetic shield to
(EGADS, SK-Gd technology)
Liquid Scintillator+Gd 121
A. Fan (SLAC) 27
New Technology#3 today TAUP2019
Shingo Kazama talk LZ Status
Poster154 Diego Ramírez Today DM16: Bjoern Penning talk
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 27G2: 2019 ~ 2025
G3: 2026~
+PandaX-4
(WINO)
DS-20K, ARGO LZ, XENON, Wino, Higgsino :
1707.08145 1802.06039 PRL 121, 111302 (2018) J. Hisano et al. Eur.Phys.J. C78 (2018)
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 28Hitoshi Murayama (Sep/9)
G2: 2019 ~ 2025
new
G3: sociology
2025 ~
• WIMP should be explored at least down
to the neutrino floor G2
• heavier? e.g., wino @ 3TeV ⟹CTA combined
• dark matter definitely exists analysis ?
• hierarchy problem may be optional?
• need to explain dark matter on its own
+PandaX-4
• perhaps we should decouple these two
• do we really need big ideas like SUSY?
• perhaps not necessarily heavier but (WINO)
rather lighter and weaker coupling?
DS-20K, ARGO LZ, XENON, Wino, Higgsino :
1707.08145 1802.06039 PRL 121, 111302 (2018) J. Hisano et al. Eur.Phys.J. C78 (2018)
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 29Summary
• Wide range DM search
• keV - TeV mass range
• low energy threshold technology by cryogenics detectors
• G2 will start commissioning in 2019, 2020
• they will reach σ ~ 10-48 cm2 with 5 years exposure.
• Challenges for G2 experiment
• rapid liquid xenon purification
• Rn background
• neutron veto
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 30Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 31
Strategy: look everywhere we can!
first day: Hitoshi Murayama
DM7 Sep.10
Hiden Photon WIMP Jules
This talk Gascon
electronic recoil nuclear recoil
EDELWEISS-III EDELWEISS-Surf
axion-like particle SIMP results
results
Evolution of the detectors from EDELWEISS-
III to EDELWEISS-SubGeV
EDELWEISS-III
Sept. 10th, 2019 EDELWEISS @ TAUP2019 3
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 32Expected backgrounds
10
Rate [counts/kg/day/keV]
Simulation of a 1000 day run of LZ
10
10
B
10
10
Rate [counts/kg/day/keV]
10
10
10
DM2: Alden Fan
10
10
10
10
Kamioka
D.S. Observatory,
Akerib et ICRR, The
al (LZ collaboration) 2018University of Tokyo, Masaki Yamashita
arXiv:1802.06039 33DM detectors join double beta decay search
Inverted Hierarchy
• 136Xe
• Natural abundance 8.8% DARWIN
Kamland-Zen
• High energy resolution@2.5MeV XENONnT
EXO-200(2018)
136Xe → 136Ba + 2e- Q:2458 keV
Energy Resolution
experiment 136Xe Mass @2.5MeV(σ)
4.2%
KamLAND- 380 kg
4.7%
Zen 750 kg (2019-)
EXO-200 200 kg 1.23%
XENONnT 500 kg 0.8%
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita 34Neutrino Floor ?
Dark Matter searches in the 2020s
At the crossroads of the WIMP
Symposium on next-generation collider,
direct, and indirect Dark Matter searches
11-13 November 2019
Kashiwa Research Complex,
Kashiwa Campus, The University of Tokyo
Scientific Organizing Committee:
O. Gekkō, Ryu sho ten, restored by A. Cuerden/ MACS J0416-1-2403, NASA, ESA, STScI, and CXC
Kohei Hayashi ICRR
Moritz Hütten Max Planck Institute for Physics
Shoji Asai The University of Tokyo/CERN
Masahiro Teshima ICRR/Max Planck Institute for Physics
Young
Shigetaka Moriyama ICRR/Kavli IPMU Scie ntists s
Abstra
ct sub ession
studen missio
Masahiro Kawasaki ICRR/Kavli IPMU t supp
ort av
n ope
n&
ailable
Shigeki Matsumoto Kavli IPMU
Masahiro Ibe ICRR
More information and registration at
Tatsuo Yoshida Ibaraki University https://indico.icrr.u-tokyo.ac.jp/e/dark-matter-symposium-2019
Masaki Yamashita ICRR
Kamioka Observatory, ICRR, The University of Tokyo, Masaki Yamashita Kentaro Miuchi Kobe University 35You can also read
