AMS the AntiMatter Spectrometer

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AMSthe Anti-Matter Spectrometer

• The past ? 1999
• The present 2000
• The future 2001-2003 and beyond
• STS-91 mission (June 1998)
• ISS 3 year mission (May 2003?)

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AMS in space

• the first large magnetic spectrometer
• i.e.
• the first particle physics experiment
• and
• the biggest silicon system to date

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AMS Physics Goals (1)

• Measurement of H, He, C isotopes
• better understanding of cosmic ray origin and
  propagation in the galaxy
• Antiprotons and positrons
• search for exotic sources
• High energy photons (gt 1 GeV)
• complementary to satellite and ground telescopes

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AMS Physics Goals (2)
Search for antimatter primary goal of AMS, up to
Z 6

• Antimatter discoveryantistars, primordial
  antimatterExplanation for antimatter domain
  formation?

• No antimatter foundexplanation for antimatter
  disappearance?Strong CP-violation?

Antihelium could originate from primordial
nucleosynthesis OR from antistars anticarbon
could ONLY come from antistars
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The AMS apparatus for the precursor flight (1)

• Construction and test of detector elements
• assembly, integration, system tests
• space qualification  outgassing, vibrations
• Permanent magnet
• 1.2m diameter, 80cm height, 1.9 tons
• 0.15 Tesla
• blocks of Nd-Fe-B of high field strength

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The AMS apparatus for the precursor flight (2)

• Tracker
• 4 inner planes and 2 outer planespartially
  equipped (40)
• 57 modules of 11 to 15 double-sided DC silicon
  microstrip detectors (CSEM, Neuch.)
• front-end Viking/High Dynamic Range4ms peaking
  time, 0.7 mW/ch
• 365W allocated (out of 1 kW), 0.5 Mbit/s (out of
  1), 5MHz ADC on ext. TDR

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The AMS apparatus for the precursor flight (3)

• Time-of-flight - 4 planes
• trigger
• particle velocity and absolute charge
• Anticoincidence - 16 counters
• background rejection (albedo)
• Aerogel Threshold Cherenkov - 2 planes
• 168 10x10cm2 7cm thick solid cells

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The STS-91 Discovery missionJune 2-12, 1998 (1)

• Transport
• from ETH-Zurich to Kennedy Space Center
• Final tests and integration
• Installation on the Shuttle Discovery
• More tests and software uploads.
• Launch
• Switch on and first data downloads!

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The STS-91 Discovery missionJune 2-12, 1998 (2)

• Data Taking
• Control from Johnson Space Center
• Slow Rate
• temperatures, currents
• counter rates, voltages
• High Rate
• calibrations
• full events (ehm)

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The STS-91 Discovery missionJune 2-12, 1998 (3)

• Landing at KSC
• Transport
• back to ETH-Zurich
• Beam tests ( cosmic muons)
• GSI-Darmstadt
• Helium, Carbon
• Cern-Geneva
• charge-1 particles

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Physics from STS-91

• Search for antihelium
• 2,86 million helium nuclei observed
• rigidity 1 to 140 GV
• Search for antimatter
• Cosmic ray proton spectra
• from 0.1 to 200 GeV
• Gamma ray search

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Que fait Genève? (1)

• Mechanical design
• support, cooling
• Construction of tracker modules (ladders)
• Tests, metrology and integration of modules

• Electronic design
• Analysis and simulations
• Silicon development
• Environmental studies
• Problem analysis from STS-91

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Que fait Genève? (2)

• full responsibility of tracker readout system
• FE electronic hybrids production test
• development of module test system
• PC card, power supply (temp)
• one of the three production lines of tracker
  modules
• module integration center

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AMS on the International Space Station (1)

• Precursor Flight final data analysis
• near completion (2000)
• RD for Phase II (1999-2001)
• design finalisation and optimisation
• superconducting magnet
• new detectors
• space qualification of single elements

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AMS on the International Space Station (2)

• 2nd construction phase
• Assembly (2000-2002)
• Full space qualification
• long-term operation tests
• Installation on the Space Station (2003)
• 3 to 5 years of data taking
• (if we get He refill)
• Lots of work and physics (and fun) ahead!