AMS : A COSMIC RAY OBSERVATORY ON THE INTERNATIONAL SPACE STATION Carlo Bosio INFN Roma La Sapienza

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AMS A COSMIC RAY OBSERVATORYON THE
INTERNATIONAL SPACE STATION Carlo Bosio INFN
- Roma La Sapienza UniversitySusy 2004 -
19 June 2004
Alpha Magnetic Spectrometer
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AMS 02
TRD Gas Cont.System

• Outline
• The Experimental Apparatus
• General Characteristics
• Detector Component
• AMS Physics Program
• particles, N, g
• AntiMatter Search
• Dark Matter

Electronics
3 x 3 x 3 m3 7000 Kg
AMS 02 Detector
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AMS 02 General characteristics

• Mechanical and geometrical characteristcs
• Minimum amount of matter (X0) before ECAL
• Acceptance 0.5 m2.Sr -gt anti-He search
• Velocity measurement Db/b 0.1 to
  distinguish 9Be,10Be,
• 3He,4He isotopes.
• Rigidity R pc/Ze (GV) proton resolution
• 20 at 0.5 TV and Helium resolution of 20 at
  1 TV.
• Antihelium/Helium identification factor 1010.
• Multiple and independent measurements to
  reach performances required
• Z measured from Tracker, RICH, TOF.
• Sign of charge Z measured from tracker (8
  points).
• Velocity b measured from TOF, RICH.
• Hadron/electron separation from TRD, ECAL.
• Detector requirements
• Suppress proton background 10 -6
• Tracking up to 1 TV

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AMS 02 General Characteristics

• Experiment in International Space Station
• (--gt Constraints for launch and space)
• Environment (day/night ?T100oC) ---gt
  Thermal
• Launch ---gtVibration (6.8 G RMS) and
  G-Forces(17G)
• Limitation Weight (14 809 lb) and Power (2000
  W)
• Vacuum lt 10-10 Torr ---gt Cooling..
• Reliable for more than 3 years ---gt
  Redundancy
• Radiation Ionizing Flux 1000 cm-2s-1
• Orbital Debris and Micrometeorites
• Must operate without services and human
  intervention

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AMS 02 Detector

• Transition Radiation Detector p/e lt 10 -2
  10-300 GeV
• 20 Layers Fleece 5248 6mm Straw Drift Tubes
  (Xe/CO2)
• Time Of Flight Upper 1,2
  trigger, ?
• scintillators, st 120ps
• Superconducting Magnet Rigidity up to 1 TeV
• BL2 0.85 Tm2 V0,6m3 charge separation, ?
• Tracker (8 layers) Charge
  separation
• 3double 2single sided silicon strips, 6m2
• Time of Flight Lower 3,4 p/e gt3s lt2 GeV
• scintillators,Dt 120ps
• RICH ?,Z2
  He3,He4,B,C Alt27,Zlt28
• Radiator (Aerogel,NAF ) 3 s 1 - 12 GeV

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AMS 02 Star Tracker
ASTC0
ASTC1
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AMS A TeV Magnetic Spectrometer
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AMS Physics program

• Precision measurement on charged
• particles and nuclei
• e, ?, p , 3,4He, B, C, 9, 10Be,
• elements Zlt25. GeV TeV range
• High Energy Cosmic Gamma ray astrophysics (GRB,
  SN,..)
• Direct search for cosmic antimatter (antihelium -
  sensitivity 10-9 )
• Indirect search for non barionic Dark Matter
• Exotics (strangelets, mquasars,..)
• Total statistic expected gt 1010 events.

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AMS Completeness of g, p, e
_

• AMS will have the unique possibility to
• measure in space, with the same detector
• g, anti-p, e spectra
• it will be the only experiment in space able to
  make an extensive test of the neutralino based
  dark matter scenario.
• No other detectors, planned or operating will be
  able to do this measurements Cosmic Rays Fluxes

_
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Cosmic anti matter
The Primordial Antimatter content of
the universe is unknown (..if there is any at
all) Cobe excludes lt 20 Mpc

• Single anti-He or anti-C nucleus in CR is a
  strong evidence of anti matter domains or anti
  stars
• Presently, no antinucleus Zgt2
• has ever been found in CR
• Very Large statistics of primary cosmic rays on a
  large energy/rigidity range
• Particle Identification including charge sign
  reconstruction and redundancy

A high energy physics detector in space for a
long period is necessary
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He
AMS Cosmic Antimatter
PRIMORDIAL ANTIMATTER Limit on antihelium 1 year
data taking
PRIMORDIAL ANTIMATTER He anti-He Comparison
AMS-01 AMS-02
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Indirect Dark Matter Search
Universe Matter budget 95 is Dark ? non
baryonic SUSY provides an excellent WIMP
candidate neutralino ?01
mixture of the superpartners of the neutral Higgs
and EW gauge bosons
Indirect limits from LEP M?gt40GeV
?01?01 ? qq- , WW-, HH-, ... ? p, e, n, p-,
anti-D, ?, e,
lost
(identifying particles)

• Completeness of AMS-02 (all the four possible
  complementary channels)
• p- Excess at High Energy ( gt 5GeV)
• D- Excess at E lt 1 GeV
• e Structure in Spectra above few GeV
• ? Energy Spectra differ from power laws,
  
• or ? line detection ?01?01 ? ??, Z?
  (1st loop)
• Measurements possible because background very
  well known

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Indirect ? detection
? ? lt ?v gt ??2/m?2 ? g(propagation) SUSY
Parameters dependence
lt ?v gt (st times relative neutralinos velocity)
tan?50
tan?5
mc 0.4 m1/2

• Coupling and mass spectrum
• Lower sensitivity for heavier ? masses

W. de Boer et al, hep-0309029
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Indirect ? detection
? ? lt ?v gt ??2/m?2 ? g(propagation) Astrophysics
/Cosmology dependence

• Clumpiness
• Dark halo profile (NWF, CRM,etc) rc
• Propagation parameters

W. de Boer et al, hep-0309029
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DM searches with positrons
e
Sensitivity to exotic flux greater than
10-7 E2(cm.s.sr.GeV)-1

• Precise measurement of the energy spectrum after
  3 years
• 1 stat error at 50 GeV.
• 30 stat error at 300 GeV

rejection e/p gt 105
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DM searches with positrons
e

• Heat Data a bump in energy at 7 GeV, no
  standard astrophysical interpretation of e/e-
  energy distribution
• Precise data extended to higher energies will be
  provided by AMS
• MSSM simulation for AMS-02 need
  high boost factors

m? ? 336 GeV
m? ? 130.3 GeV
Based on the work of E.A. Balts et al. 99 large
boost factor needed
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DM searches with anti-protons
?p
Prospects with AMS-02 after 3 years
Secondary anti protons flux
Background rejection p /?p gt 106 , e-/?p
103-104
Up to 300 GeV
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DM searches with anti-protons
?p

• M?964 GeV (?4200)
• M?777 GeV (?1200)

Sizable effects Primary ?p ,from
? annihilations
Background secondary ?p
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Dark Matter - ? ray
g
Detection rate (source)
? ?

• N? ??v? ?2 (r) dl(?) d?
• m2?

? ? ?
los
SUSY
Astrophysics
diffuse D M galactic as ? , e , p-, D-,
Direct Detection
extragalactic source D M
- Galactic Centre (G. C.) of Milky Way
- Nearby Spiral Galaxies e. g. M31, M87,
or clouds LMC, SMC - Dwarf Spheroidals
e. g. DRACO - Globular Clusters ? -
centauris, Palomar13
? Enhancement factors from cuspy halos,
clumpiness or/and SBH
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AMS-02 ?
?
Two complementary detection modes
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AMS-02 ?
?
108 cm2s
Field of View
One year sky coverage


ExtraGalactic ? spectrum
LMC
ECAL ? stand-alone trigger
Exposure of the Galactic Center


AMS-02 3 Y measurements Galactic diffuse ?
spectrum
TRDTracker
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AMS-02 ?
?
Msugra results Integrated flux from the Galactic
Center in the focus point, region for two NFW
profile parametrizations
R0 8.0 kpc, r0 0.3 GeV/cm3, a 20 kpc R0
distance earth - GC r0 halo density at R0
R0 8.5 kpc, r0 0.4 GeV/cm3, a 4 kpc a core
radius
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Susy DM summary
g
AMS offers
Precise measurements of all particle spectra
Measurements of Nuclei fluxes for propagation
model Wide range of SUSY annihilation
products. Potential gain in sensitivity by
combining them Could provide benchmark data to
validate models
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Conclusions

• AMS is a High Energy Physics detector in space
  foreseen to operate on the ISS for 3 years
• Most of the sub-detectors will be ready by end
  2004
• Detector integration in 2005
• Global Thermal-Vacuum test at ESA (Nordwijk,
  NL) end 2005 / beg. 2006
• Then AMS is ready for launch
• The cosmic rays, including gamma, will be
  measured with a high accuracy from the GeV to the
  TeV range , to search for
• Antimatter
• Dark Matter
• Cosmic Ray Fluxes and propagation
• High Energy g sources
• All the physics channels are measured in the
  same conditions and simultaneously, which will
  give a strong constraint on models and increase
  the potential of discovery. Unique opportunity to
  perform Dark Matter searches

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The End