the results of alpha magnetic spectrometer (ams01) experiment in space behcet alpat i.n.f.n. perugia...

The Results of Alpha Magnetic Spectrometer (AMS01) Experiment

in Space

Behcet Alpat

I.N.F.N. Perugia

TAUP 2001

Laboratori Nazionali del Gran Sasso, Italy

September 8-12, 2001

B. Alpat, INFN Sezione di Perugia

The AMS Physics

To search for Antimatter (He,C) in space with a sensitivity of 102 to 103 better than current limits.

To search for dark matter High statistics precision measurements of e, and p

spectrum. To study Astrophysics.

High statistics precision measurements of D, 3He, 4He, B, C, 9Be, 10Be spectrum

B/C: to understand CR propagation in the Galaxy (parameters of galactic wind).

10Be/9Be: to determine CR confinement time in the Galaxy.


AMS-01 Configuration on STS-91 Flight

STS-91 Flight, June 2-12th, 1998• Magnet: Nd2Fe14B, BL2= 0.15 TM2

• T.o.F: Four planes of scintillators;

and Z measurements, up/down separation

• Tracker: Six planes of ds silicon detectors;

• Charge sign, dE/dX up to Z=8, Rigidity (p/Z)

• Anticounters:

• Veto stray trajectories and bckgnd particles from magnet walls

• Aerogel Threshold Čerenkov:

measurements (up to 3 GeV/c) for better e/p separation

• Low Energy Particle Shielding (LEPS):

• Carbon fibre, shield from low energy (<5MeV) particles


AMS-01: STS-91 Flight

30 hours before and 105 hours after rendezvous with MIR (total of 135 hours including 11 hours of albedo measurements)

Shuttle altitude ranged from 320 to 390 km Latitudes 51.7°, All longitudes (except S.A.A.) A total of 100 million events recorded with event rates ranging from

100 Hz to 700 Hz (corresponding to 95%40% DAQ livetime)


AMS-01: STS-91 Flight Results

It was a successful flight !!

Detector test in actual space conditions Good performance of all subsystems

Physics results: Antimatter search Charged cosmic ray spectra (p,e,D,He) Geomagnetic effects on cosmic ray


AMS-01 STS-91 Flight -Search for Antihelium-

Contamination of Z=1 in the Z=2 sample: <10-4 tracker only

<10-7 tracker+TOF

Rigidity resolution for He data in flight in comparison with GSI



NHe/NHe = 1.1·10-6

Same spectrum for He, He(Ref. Phys. Lett. B461(1999)387-396)

Model Independent Limit (95% C.L.)(from Rmin=1.6 GV to variable Rmax)



54

Model Dependent Limit


AMS-01 STS-91 Flight -CR Spectrum Measurements-

At 30-40 km above Earth’s surface studies with balloons for several decades. Important contributions to the understanding of the primary CR spectrum of charged particles and of atmospheric secondary particles

Inner and outer radiation belts (1000 km-to-magnetosphere boundary) are studied by small size detectors on satellites

Intermediate region (ToA-and-Inner radiation belt) contains low radiation levels. Before AMS the satellite-based detectors have not been sensitive enough for a systematic study of CR spectrum (except SAA )


AMS-01 STS-91 Flight -CR Spectrum Measurements-


AMS-01 STS-91 Flight -Primary CR Spectra Measurements-



Primary e- Spectrum e+/(e++e-) Ratio


AMS-01 STS-91 Flight - Trapped Charged Particles on LEO-



Electron Spectra Positron Spectra



To study the properties of second spectra of up/down going protons and leptons they have been traced through the magnetic field backward and forward for a t<10 s flight time or until they do not hit ToA (40km). Two distinct components are observed depending on the total travel time they before impact with ToA: “Short-Lived” (<0.3 s): detected over all latitudes originated

everywhere but at M<0.3. Flux is independent on shuttle attitude

“Long-Lived” (>0.3 s):detected essentially at M<0.3 originated in definite regions . Flux dependent on shuttle attitude



Residence time vs. Energy for e+

Res

iden

ce ti

me

(s)


Adiabatic Invariants



Left:Integral flux maps for e+(A)/e- (B) and Right:integral e+/e- ratio between 0.205 E 2.73 GeV

L L

30

002

02

/311653.0

//

m

mm

LB

BBBBSinSin


AMS belts vs. Van Allen belts

AMS belts: High energy from ~ 1 GeV

to ~ 10 GeV Contains e+, e-, p, 3He e+ over e- dominance Low L- shell low altitude Life time O(seconds)

=> Secondary production from CR interaction with

atmosphere

Van Allen belts: Low energy from ~ 1 MeV

to ~ 700 MeV Contains e-, p High L-shells high

altitude Life time O(years) Decays of neutrons

produced in interactions of primary with the atmosphere (CRAND)

Solar wind induced magnetic storms


AMS-02 on ISS

2004


AMS-02 on ISS


AMS-02 Physics on ISS


AMS-02 as HE ray detector


Complementarity of , p, e+ with AMS02

AMS will have the unique possibility tomeasure in space, with the same detector

, 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 measurement

_


AMS-02 Physics on ISS (3 years)

Elements Yield (or Sensitivity)

(Now) Rigidity Range (GV)

Physics

e+

γ

108

500000

(~103)

(~2000)

0.1-300

0.5-100

0.1-200

Dark Matter (SUSY)

He/He

C/C

1/109

1/108

1/106

1/104

0.5-1000

0.5-1000

Antimatter

CPvsGUT, EW

D,H2

3He/4He10Be/9Be

109

109

2%

1-20

1-20

1-15

Astrophysics

p


Conclusions

AMS-01 has successfully been tested during STS-91 flight providing important information on operating in actual space conditions

AMS-01 data allows to search for antimatter and to study the energy spectra for primary and trapped CR fluxes

AMS is approved by NASA to operate on the ISS for 3 years starting in 2004

AMS-02 will extend the accurate measurements of CR spectra to unexplored TeV region opening a new window for the search for Antimatter and Darkmatter.

the results of alpha magnetic spectrometer (ams01) experiment in space behcet alpat i.n.f.n. perugia...

Documents

flight sts

infn sezione

flight search

z measurements

successful flight

flight resultsit

cr propagation

p spectrum