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Status of the AMS-02 Experiment in Space
IAS-CERN Workshop March 25, 2013
Shih-Chang Lee Institute of Physics, Academia Sinica, Taiwan
First result on positron fraction from 0.5GeV to 350GeV based on
18 months of data had been submitted for publication and will
be published soon. More results will be announced in
a special AMS session in ICRC, July 2013.
USA FLORIDA A&M UNIV. FLORIDA STATE UNIVERSITY MIT - CAMBRIDGE NASA GODDARD SPACE FLIGHT CENTER NASA JOHNSON SPACE CENTER TEXAS A&M UNIVERSITY UNIV. OF MARYLAND - DEPT OF PHYSICS YALE UNIVERSITY - NEW HAVEN
MEXICO UNAM
DENMARK UNIV. OF AARHUS
FINLAND HELSINKI UNIV. UNIV. OF TURKU
FRANCE GAM MONTPELLIER LAPP ANNECY LPSC GRENOBLE
GERMANY RWTH-I RWTH-III MAX-PLANK INST. UNIV. OF KARLSRUHE
ITALY ASI CARSO TRIESTE IROE FLORENCE INFN & UNIV. OF BOLOGNA INFN & UNIV. OF MILANO INFN & UNIV. OF PERUGIA INFN & UNIV. OF PISA INFN & UNIV. OF ROMA INFN & UNIV. OF SIENA
NETHERLANDS ESA-ESTEC NIKHEF NLR
ROMANIA ISS UNIV. OF BUCHAREST
RUSSIA I.K.I. ITEP KURCHATOV INST. MOSCOW STATE UNIV.
SPAIN CIEMAT - MADRID I.A.C. CANARIAS.
SWITZERLAND ETH-ZURICH UNIV. OF GENEVA
CHINA BISEE (Beijing) IEE (Beijing) IHEP (Beijing) NLAA (Beijing) SJTU (Shanghai) SEU (Nanjing) SYSU (Guangzhou) SDU (Jinan)
KOREA EWHA
KYUNGPOOK NAT.UNIV.
PORTUGAL
LAB. OF INSTRUM. LISBON
ACAD. SINICA (Taiwan) AIDC (Taiwan)
CSIST (Taiwan) NCU (Chung Li) NCKU (Tainan)
NCTU (Hsinchu) NSPO (Hsinchu)
TAIWAN
AMS is an International Collaboration 16 Countries, 60 Institutes and 600 Physicists, 17 years
The detectors were built all over the world and assembled at CERN, near Geneva, Switzerland
AMS detector is designed with the same precision and detection capability as the large state-of-the-art CERN Detectors.
To install AMS on the ISS we have miniaturized the CERN Detectors to fit
into the space shuttle. This has been the main technical challenge.
The AMS experiment
A magnetic spectrometer to study very high energy cosmic rays
6 5m x 4m x 3m
7.5 tons Silicon layer
7 Silicon layers
Silicon layer
TRD
TOF 1, 2
TOF 3, 4
RICH
ECAL
Magnet
300,000 electronic channels 650 processors
Radiators
11,000 Photo Sensors
Trac
ker
1
2
7-8
3-4
9
5-6
TRD Identify e+, e-
Silicon Tracker Z, P
ECAL E of e+, e-, γ
RICH Z, E
TOF Z, E
Particles and nuclei are defined by their
charge (Z) and energy (E ~ P)
Z, P are measured independently by the Tracker, RICH, TOF and ECAL
AMS: A TeV precision, multipurpose particle physics spectrometer in space.
Magnet ±Z
Tracker Entry
Tracker Exit
0.33
X0
Trac
ker T
otal
0.
50 X
0
a) Minimal material in the TRD and TOF So that the detector does not become a source of e+.
b) A magnet separates TRD and ECAL so that e+ produced in TRD will be swept away and not enter ECAL In this way the rejection power of TRD and ECAL are independent
c) Matching momentum of 9 tracker planes with ECAL energy measurements
Sensitive Search for the origin of Dark Matter with p/e+ >106
rejection >102
rejection >104
Trac
ker
e+
e+
p
p
TRD:
ECAL:
P
e+
P
e+
1.03 TeV electron
TRD: identifies electron
Tracker and Magnet: measure momentum
ECAL: identifies electron and measures
its momentum
side view
front view
RICH charge of electron
50,000 fibers, φ =1mm, distributed uniformly inside 1,200 lb of lead which provides a precision, 3-dimensional, 17X0 measurement
of the directions and energies of light rays and electrons up to 1 TeV
Calorimeter (ECAL)
Physics of AMS: Search for Antimatter Universe
It is known that the Milky Way and the galaxies around it are made of matter
predominantly. Where are the primordial antimatter in
the Universe?
AMS on ISS
The Universe began with the Big Bang. After the Big Bang there were equal amounts of matter and
antimatter.
anti-Helium? anti-Carbon?
Experimental work on Antimatter in the Universe Search for
Baryogenesis
Proton decay Super K
(τp > 6.6 * 1033 years )
Direct search
New CP BELLE BaBar
(sin 2β= 0.672±0.023 consistent with SM)
FNAL KTeV (Re(ε’/ ε) = (19.2±2.1)*10-4)
CERN NA-48 CDF, D0
LHC-b, ATLAS,CMS AMS Increase in sensitivity: x 103 – 106
Increase in energy to ~TeV No explanation found for the absence
of antimatter (no reason why antimatter should not exist)
Physics of AMS: Search for Antimatter Universe
The Origin of Dark Matter ~ 90% of Matter in the Universe is not visible and is called Dark Matter
The physics of AMS include:
A Galaxy as seen by telescope If we could see Dark Matter in the Galaxy
e+/(
e+ +
e− )
e+ Energy [GeV]
The leading candidate for Dark Matter is a SUSY neutralino (χ0 ) Collisions of χ0 will produce excess in the spectra of e+ different from known cosmic ray collisions
AMS data on ISS 1 TeV
Phys. Rev. Lett. 108, 011103 (2012)
Measurement of Separate Cosmic-Ray Electron and Positron Spectra with the Fermi Large Area Telescope
AMS-02 aims for 1% precision
First result will be from 0.5-350GeV
Detection of High Mass Dark Matter from ISS
AMS-02
e+ Energy (GeV)
e+ /(
e+ +
e- )
mχ=400 GeV mχ=200 GeV
mχ=800 GeV Peak value? Peak energy?
Run/Event 1318944028/ 505503 Run/Event 1334274023/ 338433 Electron E=99 GeV Positron E=100 GeV
front view
side view
front view
side view
Run/Event 1329775818/ 60709 Run/Event 133119-743/ 56950 Electron E=982 GeV Positron E=636 GeV
front view
side view
front view
side view
AMS 1600 e+ events (65-100 GeV)
Energy (GeV)
e+ /
(e+ +
e− )
Error size
HEAT: J.Beatty et al., Phys. Rev. Lett. 93 (2004) AMS-1: M.Aguilar et al., Phys. Lett. B 646 (2007) Pamela: O.Adriani et al., Astropart. Phys. 34 (2010) FERMI: M.Ackermann et al., PRL 108 (2012)
Science Example: Strange Quark Matter – “Strangelets”
Diamond
Strangelet
Jack Sandweiss, Yale u, d, s, c, b, t
Nucleus
Particle
Atom
Quark
All the known material on Earth is made out of u and d quarks
Is there material in the universe made up of u, d, & s quarks?
This can be answered definitively by AMS.
u d s s
d d s
s u d u d u u d d s u s u u d
d d d d d
u u u
u s u
s s
s
u d
d d
u d u d
u u d d u
u
u d d d d d d
u u u
u u
25
Strangelets
AMS-01
Z/A
Can
dida
te
Candidate observed with AMS-01 5 June 1998 11:13:16 UTC
E. Witten, Phys. Rev. D,272-285 (1984)
Z/A~0.1 All the known material on Earth is made out of u and d quarks. Is there material in the universe made up of u, d, & s quarks?
Φstrangelets = 5x10-10(cm2s sr)-1
500 Strangelet
Signals
Physics of AMS: Nuclear Abundances Measurements Φ
(m-2
sr-1
GeV
-1)
For energies from 100 MeV to 1 TeV with 1% accuracy over the 11-year solar cycle.
These spectra will provide experimental data that go into calculating the background in the Search for Dark Matter,
i.e., p + C →e+, …
Ring Imaging CHerenkov (RICH)
Li
C
O
He
Ca
160 GV
10,880 photosensors
21,760 Signal Pulses to identify nuclei and
their energy
ZTRK_L1= 26.4
ZTRD=23.9
ZTOF_UP=27.1
ZTOF_LOW=26.8
ZTRK_IN=26.9
ZRICH=26.8
ZTRK_L9=26.1
Data from ISS
Z = 7 (N) P = 2.088 TeV/c
Z = 10 (Ne) P = 0.576 TeV/c
Z = 13 (Al) P = 9.148 TeV/c
Z = 14 (Si) P = 0.951 TeV/c
Z = 15 (P) P = 1.497 TeV/c
Z = 16 (S) P = 1.645 TeV/c
Z = 19 (K) P = 1.686 TeV/c
Z = 20 (Ca) P = 2.382 TeV/c
Z = 21 (Sc) P = 0.390 TeV/c
Z = 22 (Ti) P = 1.288 TeV/c
Z = 23 (V) P = 0.812 TeV/c
Z = 26 (Fe) P = 0.795 TeV/c
AMS data: Nuclei in the TeV range
100 x 103 ly
40
x
10
3 l
y
1 x
10
3 l
y
27 x 103 ly
AMS
B/C ratio up to TeV Precise measurement of the energy spectra of B/C
provides information on Cosmic Ray Interactions and Propagation
( B )
HALO
DISK
Interactions with the Interstellar Medium: C + (p,He) → B + ...
Diffusion Convection Reacceleration
Interactions with the Interstellar Medium (ISM): • Fragmentation • Secondaries • Energy loss
Physics Example of AMS
ZTRK_L1=6.1
ZTRD=5.9
ZTOF_UP=5.9
ZTOF_LOW=5.8
ZTRK_L2-L8=5.8
ZRICH=6.1
ZTRK_L1=4.9
ZTRD=4.5
ZTOF_UP=5.0
ZTOF_LOW=5.1
ZTRK_L2-L8=4.9
ZRICH=5.2
Rigidity=215 GV Boron
Rigidity=187 GV Carbon
Rigidity ∼ 200 GV
Run/Event 1329086299/ 747549 Run/Event 132643580/ 132197 front view
side view
front view
side view
ZTRK_L1=5.2
ZTRD=5.2
ZTOF_UP=5.5
ZTOF_LOW=5.4
ZTRK_L2-L8=5.0
ZRICH=4.8
Boron Rigidity=680 GV
Rigidity ∼ 700 GV
ZTRK_L9=5.1
ZTRK_L1=5.8
ZTRD=6.0
ZTOF_UP=6.1
ZTOF_LOW=6.5
ZTRK_L2-L8=6.0
ZRICH=6.1
Rigidity=666 GV Carbon
Run/Event 1319990213/ 235892 Run/Event 1327184805/ 266043 front view
side view
front view
side view
ZTRK_L9=6.1
ZTOF_LOW=5.2
ZTRK_IN=4.8
ZRICH=5.1
ZTRK_L1=6.1
ZTRD=6.0
Z0=9.9
Z1=5.3
Carbon Fragmentation to Boron in Upper TOF Rigidity 10.6 GV
Trac
ker
1
2
7-8
3-4
9
5-6
γ Identifying γ Sources with AMS Example: Pulsars in the Milky Way
Neutron star sending radiation in a periodic way. AMS: energy spectrum up to 1 TeV and pulsar periods measured with μsec precision A factor of 1,000 improvement in Energy and Time
Unique Features: 17 X0, 3D ECAL,
Measure γ to 1 TeV,
Currently measured to energies of ~ GeV with precision of a millisec.
Physics of AMS: Measuring photons
120 GeV photon, direction
reconstructed with 3D shower sampling
Unique Features: 17 X0, 3D ECAL, measure γ to 1 TeV, time resolution of 1μsec
Polarizations of high energy photons maybe measured.
AMS-01 Collaboration Phys.Lett.B646:145-154,2007
May 19: AMS installation completed at 5:15 CDT, start taking data 9:35 CDT During the first week, we collected 100 million cosmic rays
AMS Operations
White Sands Ground Terminal, NM
AMS Computers at MSFC, AL
AMS Payload Operations Control and Science Operations Centers
(POCC, SOC) at CERN
AMS TDRS Satellites
Astronaut at ISS AMS Laptop
Ku-Band High Rate (down): Events <10Mbit/s>
S-Band Low Rate (up & down): Commanding: 1 Kbit/s Monitoring: 30 Kbit/s
AMS-02 Electronics
AMS electronics are based on accelerator physics technologies.
They are ~ 10 times faster than commercial space electronics.
They were manufactured at the Chung Shan Institute of Science and Technology (CSIST)
under the leadership of General Jinchi Hao with the support of the Director Generals of CSIST
10 Mbit/sec to Earth ~ 7 Gbit/sec
data acquisition requires fast electronics
downlink rate Is limited
Fast: 10 x the commercial space electronics Accurate: measure coordinate to 10 microns Linear: 1 in 105, 10 MeV to 1 TeV
Electronics fabricated in Taiwan, under NASA supervision
MIT
650 computers, 300,000 channels, up to 400% redundancy AMS electronics
Orbital DAQ parameters Time at location [s]
DAQ efficiency
Acquisition rate [Hz]
Particle rates vary from 200 to 2000 Hz per orbit
On average:
DAQ efficiency 85% DAQ rate ~700Hz
AMS data: He rate and Solar Flare
Polar region
Equatorial region
Quiet period Solar Flare, 24/1/2012
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
600
500
400
300
200
100
0
Even
ts/B
in
Mass (GeV/c2 )
3He
Z=2 OverCutoff β<0.85
Even
ts/B
in
Mass (GeV/c2 )
800
700
600
500
400
300
200
100
0
4He
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
2.86±0.04
3.65±0.09
Z=2 UnderCutoff β<0.85
He Rates Ev
ents
/sec
/GV
1
Based on 18 years of building and operating space electronics, we are collaborating with MIT in developing
electronics for next-generation space experiments.
Thermal Control is the most challenging task in the operation of AMS
The thermal environment on ISS is constantly changing due to: – Solar Beta Angle (β)
– Position of the ISS Radiators and Solar Arrays
– ISS Attitude
Over 1,100 temperature sensors and 298 heaters are monitored around the clock in the AMS POCC to assure components stay within
thermal limits and avoid permanent damage.
AMS
Tracker Thermal Control System in Space
Red line: CO2 gas/liquid two phase Blue line: CO2 liquid phase
Pump
Heat exchanger
Accumulator
Condenser Tracker
FMP/QMP
3 TTCS Boxes
FMS
Front
Radiator side
Tracker Thermal Control System (TTCS) used a two phase CO2 cooling design.
20/08/2011 03/10/2011 16/11/2011 30/12/2011 13/02/2012
30
20
10
0
-10
-20
Tem
pera
ture
/o C
Stability of the temperature of Tracker planes 5 and 6 over 4 months
AMS Tracker on ISS
First Data from AMS and detector performance
The detectors function as designed and, in 18 months, we have collected over 24 billion events.
Every year, we will collect 16*109 events
and in 10-20 years we will collect 160-320*109 events.
ASGC Computing Center Chief Executive Officer S.-C. Lee
• Total Capacity • 2MW, 400 tons AHUs • 93 racks • ~ 800 m2 • Current Resources • 15,000 CPU Cores • 9 PB Disk • 5 PB Tape
Monitoring the power consumption and temperature
of every piece of equipment every 10 seconds.
63
Cooling Power : CPU Power Summer 1 : 1.4
Winter 1 : 2
5 SEPTEMBER 2008 VOL 321 SCIENCE ASGC is a Tier-1 Center of World-Wide Grid
Data Center is a restricted access area. It is 24-hour monitored by video surveillance.
SiteMover
pull submit
define
Production Managers
http
https https
https
https
https
https
https
https
Data Scheduling
Job Scheduling
Data Management
System
Logging System
PanDA Brokerage Monitoring System
Task/Job Repository
(Production DB)
Submitter
CVMFS
Pilot CVMFS
Pilot CVMFS
Pilot
Pilot Scheduler (autopyfactory)
CVMFS Repository
Squid Cache
Condor-G
Production jobs
PanDA Server
PanDA: Production and Distributed Analysis System
AMS
IOP
ATLAS
Storage System
SiteMover
Storage System
Storage System
SiteMover
http
We adopt grid software developed by BNL and CERN for ATLAS to support AMS users using resources in Taiwan.
ASGC
Ruccio Server
Distributed Cloud Computing OS
developed by ASGC
Conclusion Over the past 1.8 years, we have accumulated a lot of data
and used it to understand and tune the performance of AMS.
While continuing to fine tune the detector for optimal performance, we had started to search for new physics based
on the accumulated data.
The first result on positron fraction had been submitted for publication and more results will follow soon.
We now have a precision TeV spectrometer in the space to explore the unknown of the Universe.
We welcome more young scientists to join the effort.
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