Title
Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station
Date Issued
17 November 2015
Access level
open access
Resource Type
journal article
Author(s)
Aguilar M.
Aisa D.
Alpat B.
Alvino A.
Ambrosi G.
Andeen K.
Arruda L.
Attig N.
Azzarello P.
Bachlechner A.
Barao F.
Barrau A.
Barrin L.
Bartoloni A.
Basara L.
Battarbee M.
Battiston R.
Becker U.
Behlmann M.
Beischer B.
Berdugo J.
Bertucci B.
Bindi V.
Bizzaglia S.
Bizzarri M.
Boella G.
De Boer W.
Bollweg K.
Bonnivard V.
Borgia B.
Borsini S.
Boschini M.J.
Bourquin M.
Burger J.
Cadoux F.
Cai X.D.
Capell M.
Caroff S.
Casaus J.
Castellini G.
Cernuda I.
Cerreta D.
Cervelli F.
Chae M.J.
Chang Y.H.
Chen A.I.
Chen G.M.
Chen H.
Chen H.S.
Cheng L.
Chou H.Y.
Choumilov E.
Choutko V.
Chung C.H.
Clark C.
Clavero R.
Coignet G.
Consolandi C.
Contin A.
Corti C.
Gil E.C.
Coste B.
Creus W.
Crispoltoni M.
Cui Z.
Dai Y.M.
Delgado C.
Della Torre S.
Demirköz M.B.
Derome L.
Di Falco S.
Di Masso L.
Dimiccoli F.
Díaz C.
Von Doetinchem P.
Donnini F.
Duranti M.
D'urso D.
Egorov A.
Eline A.
Eppling F.J.
Eronen T.
Fan Y.Y.
Farnesini L.
Feng J.
Fiandrini E.
Fiasson A.
Finch E.
Fisher P.
Formato V.
Galaktionov Y.
Gallucci G.
García B.
García-López R.
Gargiulo C.
Gast H.
Gebauer I.
Gervasi M.
Ghelfi A.
RWTH Aachen University
Publisher(s)
American Physical Society
Abstract
Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.
Volume
115
Issue
21
OCDE Knowledge area
Astronomía
Física de partículas, Campos de la Física
Scopus EID
2-s2.0-85007278074
Source
Physical Review Letters
ISSN of the container
00319007
Sources of information:
Directorio de Producción Científica
Scopus