Transcript Highlight of the KIMS research program and plan Sun Kee Kim

Highlight of the KIMS
research program and plan
Sun Kee Kim
Seoul National University
2nd China-Korea Workshop on Dark Matter Search
Nov. 23-25, Seoul
Brief History
 2000.12.16 Mini-workshop on WIMP search with crystals,
Seoul (Henry Wong, Jin Li)
 2001.3.21 Beijing Mini-workshop, Beijing
 2001.9.13 Cold Dark Matter Mini-workshop, Taipei
 2003.9.23 TEXONO-KIMS joint meeting, Beijing
 2004.1.29 TEXONO-KIMS Joint workshop, Yongpyung
 2006.2.6 Workshop on the underground experiments at
Yangyang
 2006.10.11 1st China-Korea joint seminar
 2007.11.22 2nd China-Korea joint seminar
Questions on Universe
 What is the Universe made of?
 How large is the Universe?
 How did the Universe begin?
 What is the destiny of the Universe?
 What is the meaning of life in the Universe?
…
Some of these questions can be answered
by understanding
the nature of Dark matter and Neutrinos
“The most incomprehensible thing about the world is that it is comprehensible”
- A. Einstein -
Composition of Universe
Mostly Dark matter, Dark energy
  matter    1.02  0.02
Known ~ 4%
property of neutrinos
not known very well
Galactic Dark Matter
rotation velocity curve
Direct detection of galactic dark matter
WIMP
Cs
I
Recoiled nucleus
Recoil energy ~ 10’s keV
Event rate < 1/kg/day
Density of dark matter around the sun ~ 0.3 GeV /cm3
~ 5 x 10-28 kg/cm3
WIMP
(Weakly Interacting Massive Particles)
Relic abundance
h
27
3 1
3

10
cm
s
2
 h 
 Av
H
~ 0.7,  A : annhilatio n cross section,  : realtive velocity
100km / s / Mpc
Annihilation cross section of a particle with a weak scale
interaction
 Av ~  2 (100GeV)2 ~ 1025 cm3s 1
 Excellent CDM candidate
LSP in SUSY
First idea of WIMP in 1977
by B.W.Lee and S. Weinberg
Elastic scattering of SUSY WIMP with ordinary nucleus
Laxial  d q    5q    5q
Spin Dependent Interaction
Isotope
J
Abun
<Sp>
<Sn>
133Cs
7/2
100%
-0.370
0.003
127I
5/2
100%
0.309
0.075
73Ge
9/2
7.8%
0.03
0.38
129Xe
1/2
26%
0.028
0.359
131Xe
3/2
21%
-0.009
-0.227
32
 spin  GF 2  2  2 J ( J  1)

1
  (a p  S p   an  Sn )
J
Spin Independent Interaction
Lscalar  aq  q q
 scalar
4
   Zf p  ( A  Z ) f n 

2
 A2
2
Status of Direct Dark Matter Search
current best limit(CDMS)
only positive result(DAMA)
Gaitskell’s summary talk IDM2004
Neutrino oscillation
Neutrino mass and mixing
measurable by neutrino oscillation
needs to be measured
DayaBay, DCHOOZ, RENO
needs to be measured
Neutrinoless Double Beta Decay
T1/ 2 0  ~  m  2 M 0
2
R = 5%
100 meV
sum electron energy / Q
energy resolution is very important
25 meV
2meV
S13
need 1 ton detector
from Ejiri’s talk (IDM2006)
Status of DBD searches
Issues
 Dark Matter


What is it ? WIMP?, Axion,…
What is its nature? Mass, SUSY,…
 Neutrinos




What is absolute mass?
Majorana or Dirac?
Magentic moment?
Mixing angle?
Underground experiments on
-Direct dark matter search
-Neutrinoless double beta decay search
-Neutrino magnetic moment with strong source
may shed light on these issues
Research Program of KIMS
Dark Matter Search
- CsI(Tl) crystal detector
Running  result was published  talks today
- Ultra-low energy HPGe detector
R&D setup is running  talks today
Neutrinoless Double Beta Decay Search
- Metal loaded liquid scintillator
Pilot experiment is running – a preliminary result
- CaMoO4 crystal
R&D effort is on going  talks tomorrow
Development of Cryogenic Detector
R&D effort is on going  talk tomorrow
Rare event experiment
Background reduction is a critical research program
Underground laboratory is essential
Yangyang Underground Laboratory
Yangyang Underground Laboratory
(Upper Dam)
Korea Middleland Power Co.
Yangyang Pumped Storage Power Plant
Construction of Lab. buildings done in 2003
(Power Plant)
(Lower Dam)
Minimum depth : 700 m / Access to the lab by car (~2km)
WIMP search with CsI(Tl) Crystals
Easy to get large mass with an affordable cost
 Good for AM study
High light yield ~60,000/MeV
Pulse shape discrimination
 Moderate background rejection
Easy fabrication and handling
Cs-133, I-127 (SI cross section ~ A2)
Both Cs-133, I-127 are sensitive to SD interaction
electron recoil
nuclear recoil
Crystals and data taking
Name
Weight
(kg)
Data
(kg days)
S0406
6.7
237
S0501A
8.7
1147
S0501B
8.7
1030
B0510A
8.7
616
B0510B
8.7
616
B0511
8.7
B0601
8.7
B0605A
8.7
B0605B
8.7
B0606A
8.7
B0606B
8.7
B0607
8.7
B0608
8.7
published
PLB(2006)
Pilot run
published PRL(2007)
Engineering run
Total crystals
8.7 kg x 12 = 104.4 kg
started data taking
made of new powder
expecting ~ 2cpd
Spin independent limit
PRL 99, 091301 (2007)
ρD=0.3 GeV/c2/cm3
v0=220km/s
vesc=650km/s
Systematic uncertainty
Fitting, Quenching factor
energy resolution...
combined in quadrature
~ 15% higher than w/o syst.
Nuclear recoil of 127I
of DAMA signal region
is ruled out unambiguiously
Spin dependent limits
PRL 99, 091301 (2007)
Pure proton case
Pure neutron case
SCIENCE, July 2007
ULE HPGe Detector for low mass WIMP
5g detector in operation at Y2L
20 g detector in preparation by TEXONO
Talks by
See Yue Qian
Shin Kai Lin
Hau-Bin Li
Liquid Scintilator for 0
NIMA 570, 454(2007)
Loading Sn
base scintillator:
PC+PPO(4g/l)+POPOP(30mg/l)
very stable over a year
Liquid Scintilator for 0
1.1 liter 30% Tin-loaded Liquid scintilator
124Sn  124Te + 2-decay
TMSN loading
9 Months data
2287keV
T1/2 > 4x1019 yr at 90% C.L
previous limit :T1/2 < 2.4x1017 yr at 90% C.L
paper in preparation
0 Search with HPGe
DBD search with HPGe
124Sn
Nucl. Phys. A 793, 171 (2007)
(5.79%)  124Te*  124Te+γ
140 hours
(TB-Sn)
(1) > 2.31018 y
(2) > 6.71018 y
(3) > 7.91018 y
HPGe + CsI(Tl) 0
Nucl. Phys. A 793, 171 (2007)
332 hours
Zn plate : 8cm x 8cm x 1cm
> 1.31020 years
F.A.Danevich et al., Nucl. Instrum. Meth. A 544, 553 (2005)
I.Bikit, et al., Appl. Radiat. Isot. 46, 455 (1995)
CaMoO4 for ββ
CaMoO4 (PbMoO4 , SrMoO4...)

DBD for Mo-100 (3034 keV), Ca-48(4272 keV)

Similar to CdWO4 but no hazard with Cd. and low Z

Light output; 10-20% of CsI(Tl) at 20o, increase with lower temp.

Decay time ; 16 μ sec

Wavelength; 450-650ns-> RbCs PMT or APD

Pulse shape discrimination
Compton edge
PSD for alpha/gamma
resolution
CaMoO4 + LAAPD at -159oC
Sensitivity of CaMoO4
Ca,Mo purification : 0.01 evt/keV/kg/y at 3MeV
Active veto(5cm PbWo4(PbMoO4)) + 15cm low bg
Pb + 30cm LSC
Time correlation , Pulse shape discrimination
Mo-100 2nu
Bi-214
Ca-48 2nu
Signal (m=0.3eV)
Tl-208
10kg (100Mo)
0.01 /kg/keV/year
6% FWHM resolution
5year  8x1024 y(~200 meV)
Current best limit on 100Mo :
4.6x1023 y by NEMO3 with 6.9kg 100Mo
Proc. New View in Particle Physics
(VIETNAM ’2004) Aug. 2004, p.449
IEEE Nucl. Sci. 52, 1131 (2005)
NIMA, in print (2007)
Crystal Growth (ISTC program)
New crystal 25 mm x 25 mm x 123 mm
installed @ Y2L, taking data now
 J.I.Lee’s talk tomorrow
Newest crystal
Newer crystals
Underground Lab. Space
실험실공간
40m
800 sq m
40m
8m
실험실 공간
320 sq m
90
20m
New Lab. space
40 m x 20 m = 800 m2
Current Lab. ~ 100m2
Planned underground Lab.
40.00
실험실 1
실험실 1
실험실 1
100 sq m
100 sq m
100 sq m
지원시설
실험실 1
실험실 1
50 sq m
50 sq m
50 sq m
지하공간
20.00
800 sq m
Underground Lab.
•Lab. 10x10=100m2 x 3
•Lab. 10x5 = 50m2 x 2
•Mini Machine shop
•Liquid N2/He facility
•Parking space
•Service/utility space
사무실
실험실 1
49 sq m
100 sq m
Current Lab. space
Summary
DM/DBD : Hottest research topics
KIMS started to produce good physics results
A lot of efforts for new detector development
Competitive DBD search can be realized rather
soon
Possibility of larger underground laboratory
space at Y2L is being explored
Cooperative and harmonious international
collaboration will be essential