1. AMS : A COSMIC RAY OBSERVATORY ON THE INTERNATIONAL SPACE STATION Carlo Bosio INFN - Roma ‘La Sapienza’ University Susy June 2004
Alpha
Magnetic
Spectrometer

2. AMS 02 AMS 02 Detector Outline: The Experimental Apparatus
General Characteristics
Detector Component
AMS Physics Program:
particles, N, g
AntiMatter Search
Dark Matter
TRD Gas
Cont.System
Electronics
3 x 3 x 3 m3
7000 Kg
AMS 02 Detector
November 22, 2018
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3. AMS 02: General characteristics:
Mechanical and geometrical characteristcs
Minimum amount of matter (X0) before ECAL
Acceptance 0.5 m2.Sr -> anti-He search
Velocity measurement Db/b = 0.1 % to distinguish 9Be,10Be,
3He,4He isotopes.
Rigidity R= pc/|Z|e (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
November 22, 2018
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4. AMS 02: General Characteristics
Experiment in International Space Station
(--> Constraints for launch and space):
Environment (day/night: T~100oC) > Thermal
Launch: --->Vibration (6.8 G RMS) and G-Forces(17G)
Limitation : Weight ( lb) and Power (2000 W)
Vacuum: < Torr > Cooling..
Reliable for more than 3 years > Redundancy
Radiation: Ionizing Flux ~1000 cm-2s-1
Orbital Debris and Micrometeorites
Must operate without services and human intervention
November 22, 2018
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5. AMS 02: Detector
Transition Radiation Detector : p+/e+ < GeV
20 Layers Fleece mm 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 V=0,6m charge separation, 
Tracker (8 layers) : Charge separation
3double +2single sided silicon strips, 6m2
Time of Flight Lower 3, p+/e+ >3s <2 GeV
scintillators,Dt =~120ps
RICH : ,Z2 He3,He4,B,C A<27,Z<28
Radiator (Aerogel,NAF ) s GeV
Electromagnetic Calorimeter :e, to 1 TeV, p+/e+ < 10 -4
Lead+scint. Fibers, 324 R7600 PMT’s (4 pixels)
November 22, 2018
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6. AMS 02 : Star Tracker ASTC0 ASTC1 ASTC1 ASTC0 November 22, 2018
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7. AMS: A TeV Magnetic Spectrometer
November 22, 2018
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8. AMS Physics program Precision measurement on charged
particles and nuclei:
e±, , p± , 3,4He, B, C, 9, 10Be,
elements Z< 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 > 1010 events.
November 22, 2018
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9. 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 _
November 22, 2018
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10. The Primordial Antimatter content of the universe is unknown
Cosmic anti matter
The Primordial Antimatter content of the universe is unknown
(..if there is any at all…)
Cobe excludes < 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 Z>2
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
November 22, 2018
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11. PRIMORDIAL ANTIMATTER PRIMORDIAL ANTIMATTER_ He
AMS: Cosmic Antimatter
PRIMORDIAL ANTIMATTER
He anti-He
Comparison AMS-01 AMS-02
PRIMORDIAL ANTIMATTER
Limit on antihelium
1 year data taking
November 22, 2018
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12. 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>40GeV
0101  qq- , W+W-, H+H-, ...  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 ( > ~ 5GeV)
D- : Excess at E < 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
November 22, 2018
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13. Indirect  detection   < v > 2/m2  g(propagation)
SUSY Parameters dependence
< v > (st times relative neutralino’s 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
November 22, 2018
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14. Indirect  detection   < v > 2/m2  g(propagation)
Astrophysics/Cosmology dependence:
Clumpiness
” Dark” halo profile (NWF, CR&M,etc) rc
Propagation parameters
W. de Boer et al, hep
November 22, 2018
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15. DM searches with positrons
Sensitivity to exotic flux greater than 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 > 105
November 22, 2018
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16. DM searches with positrons
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  GeV
m  336 GeV
Based on the work of E.A. Balts et al. 99 large boost factor needed
November 22, 2018
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17. DM searches with anti-protons
Prospects with AMS-02 after 3 years
Secondary anti protons flux
Background rejection : p /p > 106 , e-/p
Up to 300 GeV
November 22, 2018
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18. DM searches with anti-protons
M=964 GeV (4200)
M=777 GeV (1200)
Sizable effects:
Primary p ,from  annihilations
Background secondary p
November 22, 2018
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19. 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
November 22, 2018
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20.  AMS-02  Two complementary detection modes : November 22, 2018
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21. Exposure of the Galactic Center
AMS-02 
108 cm2s
Field of View
One year sky coverage * *
ExtraGalactic  spectrum
ECAL +  stand-alone trigger
LMC
Exposure of the Galactic Center * *
AMS-02 3 Y measurements
Galactic diffuse  spectrum
TRD+Tracker
November 22, 2018
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22. 
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
November 22, 2018
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23. Susy DM: summary AMS offers: g
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
November 22, 2018
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24. 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
November 22, 2018
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25. The End
November 22, 2018
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