Physics Results From Alpha Magnetic Spectrometer 1998 Shuttle Flight

TL;DR

The AMS experiment aboard the space shuttle in 1998 detected no antimatter and observed high-energy protons, positrons, and electrons, providing new insights into cosmic ray flux and particle behavior in Earth's radiation belts.

Contribution

This paper reviews the 1998 AMS flight results, highlighting the first detection of high-energy particles and setting new limits on antimatter presence in space.

Findings

No antimatter detected, antimatter limit set at 1.1×10⁻⁶

Detected high-energy protons, positrons, and electrons up to several GeV

Observed differences in proton spectrum compared to atmospheric neutrino models

Abstract

The Alpha Magnetic Spectrometer (AMS) is a particle detector designed to detect antimatter. During the 10-day test flight on the space shuttle in June 1998, AMS detected $10^8$ events. Upon analysis, no antimatter was found and the antimatter limit was reduced to $1.1\times10^{-6}$. The proton spectrum shows some differences with the cosmic ray flux used in atmospheric neutrino simulation. A large amount of protons, positrons, and electrons were found below the geomagnetic rigidity cutoff. The energy of these particles are as high as several GeV, one order of magnitude higher than any previously measured energy in radiation belts. These particles also exhibit many interesting features. This paper reviews the results in the four published papers of the AMS collaboration and provides explanation for some features of the albedo particles.