1 / 27

COSMIC RAY PHYSICS WITH AMS

COSMIC RAY PHYSICS WITH AMS. Joseph Burger MIT On behalf of the AMS-02 collaboration EPS2003 Aachen Particle Astrophysics July 17, 2003. Joseph.Burger@cern.ch. Cosmic Rays: p, D, He, C,…,e + ,e - , γ Direct Search for Cosmic Antimatter Other Searches: Strangelets,…

amos-roberts
Download Presentation

COSMIC RAY PHYSICS WITH AMS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COSMIC RAY PHYSICSWITH AMS Joseph Burger MIT On behalf of the AMS-02 collaboration EPS2003 Aachen Particle Astrophysics July 17, 2003 Joseph.Burger@cern.ch

  2. Cosmic Rays: p, D, He, C,…,e+,e-,γ • Direct Search for Cosmic Antimatter • Other Searches: Strangelets,… • Dark matter search in morning session talk by Mariusz Sapinski

  3. Cosmic Ray Flux AMS-02 is a large acceptance magnetic spectrometer which will extend high statistics measurements of cosmic ray properties to high rigidities.

  4. AMS-023 years on ISS starting 2005-2006

  5. Precursor Flight on STS91, June 2-12, 1998 10 days technical checkout also brought physics results and six publications: "Search for Antihelium in Cosmic Rays", M. Aguilar et al., Phys. Lett. B461 ( 2 Sep 1999) 387-396 "Protons in Near Earth Orbit", M. Aguilar et al., Phys. Lett. B472 (26 Jan 2000) 215-226 "Leptons in Near Earth Orbit", M. Aguilar et al., Phys. Lett. B484 (27 Jun 2000) 10-22 "Cosmic Protons", M. Aguilar et al., Phys. Lett. B490 (28 Sep 2000) 27-35 "Helium in Near Earth Orbit", M. Aguilar et al., Phys. Lett. B494 (30 Nov 2000) 193-202 "The Alpha Magnetic Spectrometer (AMS) on the International Space Station, Part I, Results from the test flight on the Space Shuttle", M. Aguilar et al., Physics Reports, vol. 366/6 (Aug.2002), pp.331-404. on e±, p, antiprotons, D, He, antihelium,…

  6. AMS-02 TRD (Transition Radiation Detector) Separates e± from p, p̅ < 10-2-10-3 from 10-300 GeV ToF (Upper Time of Flight) Velocity measurement, dE/dX, fast trigger Star Tracker (pointing to <1’) Superconducting Magnet 0.8T field for momentum, sign of charge Silicon Tracker 8 x-y planes with 10/30μm resolution, dE/dX Anticoincidence Counter Vetoes particles from outside trigger aperture ToF (Lower Time of Flight) Velocity measurement, dE/dX, fast trigger RICH (Ring Imaging Čerenkov Counter) Precision β measurement - separates isotopes ECAL (Electromagnetic Calorimeter) Separates e± from p, p̅ < 10-3-10-4

  7. Transition Radiation Detector (TRD) TRD Beam Test  Highly relativistic charged particle generates photons at the boundary between media (εr1 ≠ εr2)  Emission probability small (10-2)  20 layers  Photons detected in ~5300 straw tubes Good photon identification: gas with high atomic number Z Xe:CO2 80:20

  8. Time of Flight Counters Upper and lower each two layers of crossed scintillators Time-of flight to ~140psec for β and direction dE/dx measures Z (ΔE/E ~10% for MIPs)

  9. Superconducting Magnet 2500 liters superfluid He planned to last 3 years without refill Field ~1T  measurement of rigidity to a few TV

  10. Silicon Tracker Eight layers of double sided Si detectors ~10μm in bending direction, ~30μm orthogonal Measures rigidity up to a few TV Measures dE/dx for determining Z

  11. Ring Imaging Cherenkov Counter (RICH) Accurate Velocity Measurements via Opening Angle of Čerenkov Cone  / ~ 0.1%Isotopic Separation. |Q| measurements Additional Particle Identification capability

  12. Electromagnetic Calorimeter 16 X0 of lead/scintillating fiber sandwiches Crossed layers for 3D sampling by 384 4-pixel PMTs ΔE/E ~ (12±0.4)%/√E̅+(2.8±0.1)% (E in GeV) Distinguishes between hadrons and e,γ by shower shape Protons suppressed by 10-3-10-4 from 10 to 300 GeV Together with TRD ~10-6 Photon detector with angular resolution ~1°

  13. Nuclei in Space The distribution of nuclei in cosmic rays is similar to the distribution in the solar system with some exceptions. Li (except 7Li), Be and B were not produced in the primordial nucleosynthesis, nor made in stars, but by spallation reactions involving p and α colliding with C,N,O in supernovas. Measure cosmic ray confinement time in galaxy and mean density of interstellar matter.

  14. AMS-02 Expected Performance1 year 10Be/9Be ratio measurement Among all β-radioactive secondary nuclei in cosmic rays, 10Be is the lightest isotope having a half-life comparable with the confinement time of cosmic rays in the galaxy (~2x106 yr). AMS-02 will be able to separate 10Be from stable 9Be in the range 0.15<E<10 GeV/n. AMS-02 will collect 105 10Be in 3 years.

  15. AMS-02 Expected Performance6 months B/C ratio measurement In 3 years AMS-02 will collect 105 C and 104 B with energies above 100 GeV/n, measuring the ratio of boron to its primary carbon up to 1 TeV/n

  16. AMS-02 Expected Performance1 day 3He/4He ratio measurement AMS-02 can distinguish 3He from 4He in the range 0.1<E<10 GeV/n

  17. Search for AntimatterAMS-01 10 day precursor flight

  18. Search for AntimatterAMS-01 10 day precursor flight

  19. Search for AntimatterAMS-02 sensitivity in 3 years

  20. Search for AntimatterAMS-02 sensitivity in 3 years

  21. Dark Matter Search: AMS-02 e+ Flux Structure in spectrum from SUSY neutralinos χ0 Examples for mχ 336 GeV and 130.3 GeV

  22. AMS-02 Antiproton Flux AMS-02 will measure the antiproton spectrum with a few percent energy resolution up to hundreds of GeV

  23. Other Exotic Matter: Strangelets • Heavy Particle with Low Charge • Stable mixtures of u,d,s quarks with many different quarks in lowest energy state • Signature is anomalous Z/A (Z~0.3A2/3)(nuclei Z/A=0.33-0.67)  AMS sensitive to ~10<A<3000

  24. AMS-02 Sensitivity to Strangelets Shaded region from rough estimate of strangelet creation and absorption in galaxy (Chikanian et al.)

  25. Search for doubly charged anomalously heavy nuclei with AMS-01 More than 4x106 He events collected during 10 day STS91 flight Searched for anomalously heavy nuclei (Z/A ~ β·γ·mproton/Rigidity) Tight quality cuts on measured rigidity and velocity One candidate event found, corresponding to flux 5x10-5(m2·sr·sec)-1 Estimate background from ordinary nuclei < 10-3 events

  26. Summary / Conclusions • COSMIC RAY PROPAGATION light isotope abundances • ANTIMATTER SEARCH limit on antihelium/helium 10-9 • STRANGE MATTER SEARCH anomalous Z/A • DARK MATTER • SOMETHING NEW?

More Related