arXiv subjects

01 Collaboration

Publications and source records attributed to 01 Collaboration.

5 recordsLinked to original sources

arXiv2011

Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01

The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be) and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.

astro-ph.HE↗

arXiv2011

Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays. Results from AMS-01

Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper the relative abundances of the light nuclei lithium, beryllium, boron and carbon are presented. The secondary to primary ratios Li/C, Be/C and B/C have been measured in the kinetic energy range 0.35-45 GeV/nucleon. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary to secondary ratios Li/Be, Li/B and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data.

astro-ph.HE↗

arXiv2007

Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01

A measurement of the cosmic ray positron fraction e+/(e+ + e-) in the energy range of 1-30 GeV is presented. The measurement is based on data taken by the AMS-01 experiment during its 10 day Space Shuttle flight in June 1998. A proton background suppression on the order of 10^6 is reached by identifying converted bremsstrahlung photons emitted from positrons.

astro-ph↗

arXiv2004

A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected $10^8$ cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary $π^-$ and $μ^-$ emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.

hep-ex↗

arXiv1997

Nuclear Effect in Higher-Dimensional Factorial Moment Analysis of the ^{16}O-, ^{32}S- and ^{197}Au-Em Interaction Data at 200, 60 and 11 A GeV/c

The anomalous behavior of 2-dimensional factorial moment in nucleus-nucleus collisions is studied in some detail using both mini-bias and central collision data of ^{16}O-, ^{32}S- and ^{197}Au-Em interactions from EMU01 experiment. The correct value for the effective Hurst exponent in the analysis of higher-dimensional factorial moment is found to be greater than unity, showing clearly the existence of superposition effect in nucleus-nucleus collisions.

hep-ph↗