Charge and energy dependence of the residence time of cosmic ray nuclei below 15 GeV/nucleon

Soutoul, A.; Engelmann, J. J.; Ferrando, P.; Koch-Miramond, L.; Masse, P.; Webber, W. R.

The relative abundance of nuclear species measured in cosmic rays at Earth has often been interpreted with the simple leaky box model. For this model to be consistent an essential requirement is that the escape length does not depend on the nuclear species. The discrepancy between escape length values derived from iron secondaries and from the B/C ratio was identified by Garcia-Munoz and his co-workers using a large amount of experimental data. Ormes and Protheroe found a similar trend in the HEAO data although they questioned its significance against uncertainties. They also showed that the change in the B/C ratio values implies a decrease of the residence time of cosmic rays at low energies in conflict with the diffusive convective picture. These conclusions crucially depend on the partial cross section values and their uncertainties. Recently new accurate cross sections of key importance for propagation calculations have been measured. Their statistical uncertainties are often better than 4% and their values significantly different from those previously accepted. Here, these new cross sections are used to compare the observed B/C+O and (Sc to Cr)/Fe ratio to those predicted with the simple leaky box model.

Document ID

19850025696

Acquisition Source

Legacy CDMS

Document Type

Conference Paper

Authors

Date Acquired

August 12, 2013

Publication Date

August 1, 1985

Publication Information

Publication: 19th Intern. Cosmic Ray Conf - Vol. 2

Subject Category

Report/Patent Number

Accession Number

85N34009

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Public

Work of the US Gov. Public Use Permitted.

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