scholarly journals Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

2019 ◽  
Vol 209 ◽  
pp. 01007
Author(s):  
Francesco Nozzoli
Keyword(s):  
Electron Flux ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Precision Measurements ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Positron Flux ◽  
Rigidity Dependence ◽  
Alpha Magnetic Spectrometer

Precision measurements by AMS of the fluxes of cosmic ray positrons, electrons, antiprotons, protons as well as their rations reveal several unexpected and intriguing features. The presented measurements extend the energy range of the previous observations with much increased precision. The new results show that the behavior of positron flux at around 300 GeV is consistent with a new source that produce equal amount of high energy electrons and positrons. In addition, in the absolute rigidity range 60–500 GV, the antiproton, proton, and positron fluxes are found to have nearly identical rigidity dependence and the electron flux exhibits different rigidity dependence.

REVIEW OF PRECISION MEASUREMENTS OF HIGH ENERGY ELECTRONS

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1613-1624 ◽  
Author(s):  
BRUNA BERTUCCI
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Particle Identification ◽  
Energy Spectra ◽  
Precision Measurements ◽  
Low Intensity ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Experimental Effort ◽  
Experimental Challenge

An accurate measurement of the intensity and energy spectra of Cosmic Ray electrons and positrons represents a major experimental challenge. Long exposure times and excellent particle identification capabilities are needed in order to cope with the low intensity of the electron and positron fluxes and the overwhelming background from protons and nuclei in cosmic rays. The motivations for such an experimental effort will be briefly discussed and the most recent results revieweved together with the perspectives of future experiments.

scholarly journals Observation of Properties of Primary and Secondary Cosmic Rays by the Alpha Magnetic Spectrometer on the International Space Station

2019 ◽  
Vol 208 ◽  
pp. 13002
Author(s):  
Alberto Oliva
Keyword(s):  
Cosmic Rays ◽  
International Space Station ◽  
Spectral Index ◽  
Space Station ◽  
Cosmic Ray ◽  
Magnetic Spectrometer ◽  
Light Nuclei ◽  
International Space ◽  
Rigidity Dependence ◽  
Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer (AMS-02) is a wide acceptance high-energy physics experiment installed on the International Space Station in May 2011 and operating continuously since then. With a collection rate of approximately 1.7 × 1010 events/year, and the combined identification capabilities of 5 independent detectors, AMS-02 is able to precisely separate cosmic rays light nuclei (1 ≤ Z ≤ 8). Knowledge of the precise rigidity dependence of the light nuclei fluxes is important in understanding the origin, acceleration, and propagation of cosmic rays. AMS-02 collaboration has recently released the precise measurements of the fluxes of light nuclei as a function of rigidity (momentum/charge) in the range between 2 GV and 3 TV. Based on the observed spectral behaviour, the light nuclei can be separated in three distinct families: primaries (hydrogen, helium, carbon, and oxygen), secondaries (lithium, beryllium, and boron), and mixed (nitrogen). Spectral indices of all light nuclei fluxes progressively harden above 100 GV. Primary cosmic ray fluxes have an identical hardening above 60 GV, of about γ = 0.12 ± 0.04. While helium, carbon and oxygen have identical spectral index magnitude, the hydrogen spectral index shows a different magnitude, i.e. the primary-to-primary H/He ratio is well described by a single power law above 45 GV with index -0.077 ± 0.007. Secondary cosmic ray fluxes have identical rigidity dependence above 30 GV. Secondary cosmic rays all harden more than primary species, and together all secondary-to-primary ratios show a hardening difference of 0.13 ± 0.03. Remarkably, the nitrogen flux is well described over the entire rigidity range by the sum of the primary flux equal to 9% of the oxygen flux and the secondary flux equal to 62% of the boron flux.

Astrophysics and Particle Physics in Space with the Alpha Magnetic Spectrometer

2003 ◽  
Vol 18 (28) ◽  
pp. 1951-1966 ◽  
Author(s):  
Giovanni Lamanna
Keyword(s):  
Particle Physics ◽  
Gamma Ray ◽  
Space Shuttle ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Magnetic Spectrometer ◽  
High Energy Particle ◽  
Physics Experiment ◽  
Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer (AMS) is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (> 1 GeV ) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic-ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the anti-matter and the dark matter searches.

scholarly journals Possible origin of the slow-diffusion region around Geminga

2019 ◽  
Vol 488 (3) ◽  
pp. 4074-4080 ◽  
Author(s):  
Kun Fang ◽  
Xiao-Jun Bi ◽  
Peng-Fei Yin
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Diffusion Region ◽  
Late Time ◽  
Slow Diffusion ◽  
Strong Turbulence ◽  
Streaming Instability ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Γ Ray

ABSTRACT Geminga pulsar is surrounded by a multiTeV γ-ray halo radiated by the high-energy electrons and positrons accelerated by the central pulsar wind nebula (PWN). The angular profile of the γ-ray emission reported by High-Altitude Water Cherenkov Observatory indicates an anomalously slow diffusion for the cosmic-ray electrons and positrons in the halo region around Geminga. In the paper we study the possible mechanism for the origin of the slow diffusion. At first, we consider the self-generated Alfvén waves due to the streaming instability of the electrons and positrons released by Geminga. However, even considering a very optimistic scenario for the wave growth, we find this mechanism does not work to account for the extremely slow diffusion at the present day, if taking the proper motion of Geminga pulsar into account. The reason is straightforward as the PWN is too weak to generate enough high-energy electrons and positrons to stimulate strong turbulence at the late time. We then propose an assumption that the strong turbulence is generated by the shock wave of the parent supernova remnant (SNR) of Geminga. Geminga may still be inside the SNR, and we find that the SNR can provide enough energy to generate the slow-diffusion circumstance. The TeV haloes around PSR B0656+14, Vela X, and PSR J1826-1334 may also be explained under this assumption.

Fresh insights on properties of particle fluxes in cosmic rays measured with the Alpha Magnetic Spectrometer on the international space station

2021 ◽  
Vol 36 (12) ◽  
pp. 2130011
Author(s):  
Ziyuan Li ◽  
Jie Feng
Keyword(s):  
Cosmic Rays ◽  
Particle Physics ◽  
Space Station ◽  
Cosmic Ray ◽  
New Physics ◽  
Magnetic Spectrometer ◽  
Proton Spectrum ◽  
Momentum Dependence ◽  
Positron Flux ◽  
Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer is a particle physics detector focusing on the search for dark matter, the existence of antimatter, the origin and composition of cosmic rays from primordial sources in the universe and the exploration of new physics in space. Important features of the elementary particle (proton, antiproton, positron and election) fluxes in cosmic rays are presented: (1) The proton spectrum has a smooth hardening from 200 GeV; (2) antiproton and positron spectra show excess from traditional physics background; (3) in particular, the positron flux shows a source term with a cutoff energy of 810 GeV, which raises the question of its source; (4) the origin of the energetic electrons is different from that of positrons and (5) the identical momentum dependence of primary and secondary cosmic ray nuclei fluxes are also reviewed.

Sign in / Sign up

Export Citation Format

Share Document