Search for Antimatter with the AMS Cosmic Ray Detector

Technical Report · Mon Mar 24 04:00:00 EST 2003

DOI:https://doi.org/10.2172/812975· OSTI ID:812975

Cristinziani, Markus ^[1]

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1. SLAC

Antimatter search results of the Alpha Magnetic Spectrometer (AMS) detector are presented. About 10{sup 8} triggers were collected in the 1998 precursor flight onboard space shuttle Discovery. This ten day mission exposed the detector on a 51.7{sup o} orbit at an altitude around 350km. Identification of charged cosmic rays is achieved by multiple energy loss and time-of-flight measurements. Bending inside the 0.15T magnetic volume yields a measurement of the absolute value of the particle's rigidity. The supplemental knowledge of the sense of traversal identifies the sign of the charge. In the rigidity range 1 < R < 140 GV no antinucleus at any rigidity was detected, while 2.86 x 10{sup 6} helium and 1.65 x 10{sup 5} heavy nuclei were precisely measured. Hence, upper limits on the flux ratio {bar Z}/Z are given. Different prior assumptions on the antimatter spectrum are considered and corresponding limits are given.

• Research Organization: Stanford Linear Accelerator Center, Menlo Park, CA (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 812975
• Report Number(s): SLAC-PUB-9691
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALTITUDE
ANTIMATTER
BENDING
HEAVY NUCLEI
HELIUM
MAGNETIC SPECTROMETERS
PRECURSOR
SPACE SHUTTLES