Models of the knee in the energy spectrum of cosmic rays

Abstract

The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of several models are summarized, including diffusive acceleration of cosmic rays in shock fronts, acceleration via cannonballs, leakage from the Galaxy, interactions with background particles in the interstellar medium, as well as new high-energy interactions in the atmosphere. The calculated energy spectra and mean logarithmic masses are compiled and compared to results from direct and indirect measurements.

On the Planck scale and properties of matter

“…A review article of the present models of the knee and ankle is presented in Hörandel [5]. None of the models is based on any type of period doubling.…”

Contribution of pulsars to the cosmic rays in the Galaxy

“…The model has to determine such basic parameters as: the expansion velocity of the nebula, the pulsar wind shock radius, the outer radius of the nebula, the average density of matter and magnetic field strength inside the nebula, and others. The details of such a simple model for the pulsar wind nebulae (PWNe) are described in our previous papers (Bednarek & Bartosik 2003, 2004.…”

Performance of the Tibet hybrid experiment (YAC-II + Tibet-III + MD) to measure the energy spectra of the light primary cosmic rays at energies 50–10,000 TeV

“…Such break structure of the all-particle energy spectrum is called the ''knee'', and the corresponding energy range is so called ''knee region''. The special structure of the power law spectrum is considered to be closely related to the origin, acceleration and propagation mechanism of cosmic rays in the galaxy; however, its origin has not been well understood [3] due to the lack of detailed information about the chemical composition around the knee. The best ways to study the chemical http://dx.doi.org/10.1016/j.astropartphys.2014.12.013 0927-6505/Ó 2015 Elsevier B.V. All rights reserved.…”