The helium spectrum from 0.1 to 100 GeV/nucleon was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at altitudes near 380 km. Above the geomagnetic cutoff the spectrum is parameterized by a power law. Below the geomagnetic cutoff a second helium spectrum was observed. In the second helium spectra over the energy range 0.1 to 1.2 GeV/nucleon the flux was measured to be (6.3±0.9)×10−3 (m2 sec sr)−1 and more than ninety percent of the helium was determined to be 3He (at the 90% CL). Tracing helium from the second spectrum shows that about half of the 3He travel for an extended period of time in the geomagnetic field and that they originate from restricted geographic regions similar to protons and positrons.

Alcaraz, J., Alpat, B., Ambrosi, G., Anderhub, H., Ao, L., Arefiev, A., et al. (2000). Helium in near Earth orbit. PHYSICS LETTERS. SECTION B, 494(3–4), 193-202 [10.1016/S0370-2693(00)01193-X].

Helium in near Earth orbit

BOELLA, GIULIANO FILIPPO;GERVASI, MASSIMO;Grandi, D;
2000

Abstract

The helium spectrum from 0.1 to 100 GeV/nucleon was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at altitudes near 380 km. Above the geomagnetic cutoff the spectrum is parameterized by a power law. Below the geomagnetic cutoff a second helium spectrum was observed. In the second helium spectra over the energy range 0.1 to 1.2 GeV/nucleon the flux was measured to be (6.3±0.9)×10−3 (m2 sec sr)−1 and more than ninety percent of the helium was determined to be 3He (at the 90% CL). Tracing helium from the second spectrum shows that about half of the 3He travel for an extended period of time in the geomagnetic field and that they originate from restricted geographic regions similar to protons and positrons.
Articolo in rivista - Articolo scientifico
Cosmic rays: helium
English
2000
494
3–4
193
202
none
Alcaraz, J., Alpat, B., Ambrosi, G., Anderhub, H., Ao, L., Arefiev, A., et al. (2000). Helium in near Earth orbit. PHYSICS LETTERS. SECTION B, 494(3–4), 193-202 [10.1016/S0370-2693(00)01193-X].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/34451
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