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+

There are 9 planes with 200,000 channels aligned to 3 microns

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)

Rej

ectio

n ECAL rejection (E/P>0.5)

AMS ECAL on ISS

Prot

on re

ject

ion

at 9

0% e

+ effi

cien

cy

Rigidity (GV)

• ISS data

TRD performance on ISS

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)

Are there kinks in the spectra?

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

Data from ISS

Z=26.8

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

He Li Be B C

N O F Ne

Na Mg

Al Si 16

14 12 10 8 6 4 2

TOF

AMS Data on ISS from Cosmic Nuclei

Z

Z

Z

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

1.2 TeV Photon

Polarizations of high energy photons maybe measured.

AMS-01 Collaboration Phys.Lett.B646:145-154,2007

First look at gamma-ray sky with converted photons Sadakazu Haino

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

General Charles Bolden, NASA Administrator, inaugurated AMS POCC, June 23, 2011

NASA Officials Certified Asia POCC at Taiwan on June 22, 2012

NCU POCC, December 10, 2012

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 on ISS: He rate

103

Polar region Quiet period Solar Flare, 24/1/2012

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.

58

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.