Cosmic Rays from the Knee to the Ankle

Investigations of the energy spectrum as well as the mass composition of cosmic rays in the energy range of PeVto EeV are important for understanding both, the origin of the galactic and the extragalactic cosmic rays. Recently, three modern experimental installations (KASCADE-Grande, IceTop, Tunka-133), dedicated to investigate this primary energy range, have published new results on the all-particle energy spectrum. In this short review these results are presented and the similarities and differences discussed. In addition, the effects of using different hadronic interaction models for interpreting the measured air-shower data will be examined. Finally, a brief discussion on the question if the present results are in agreement or in contradiction with astrophysical models for the transition from galactic to 10 pagesextragalactic origin of cosmic rays completes this paper.Comment: 10 pages, proceedings of TAUP 2013 conferenc

Air Shower Measurements in the Primary Energy Range from PeV to EeV

Recent results of advanced experiments with sophisticated measurements of cosmic rays in the energy range of the so called knee at a few PeV indicate a distinct knee in the energy spectra of light primary cosmic rays and an increasing dominance of heavy ones towards higher energies. This leads to the expectation of knee-like features of the heavy primaries at around 100 PeV. To investigate in detail this energy region several new experiments are or will be devised.Comment: 4 pages; submitted to Proceedings of 2nd Workshop on TeV Astrophysics, Aug 28-31, 2006, Madison, W

Extensive Air Showers and Accelerator Data - The NEEDS Workshop

Very high energy cosmic rays are typically studied by measuring extensive air showers formed by secondary particles produced in collisions with air nuclei. The indirect character of the measurement makes the physics interpretation of cosmic ray data strongly dependent on simulations of multiparticle production in showers. In April 2002 about 50 physicists met in Karlsruhe to discuss various aspects of hadronic multiparticle production with the aim of intensifying the interaction between high energy physics and cosmic ray groups. Current and upcoming possibilities at accelerators for measuring features of hadronic interactions of relevance to air showers were the focus of the workshop. This article is a review of the discussions and conclusions.Comment: 10 pages, 11 figures, talk given at 12th ISVHECRI, Geneva, July 15-20, 200

Radio detection of cosmic rays: present and future

Digital radio detection of cosmic rays has made tremendous progress over the past decade. It has become increasingly clear where the potential --- but also the limitations --- of the technique lie. In this article, we discuss roads that could be followed in future radio detection efforts and try to evaluate the associated prospects and challenges.Comment: Contribution to the Proceedings of the UHECR2014 conference, Springdale, UT; to be published in JPS Conf. Pro

KASCADE: Astrophysical results and tests of hadronic interaction models

KASCADE is a multi-detector setup to get redundant information on single air shower basis. The information is used to perform multiparameter analyses to solve the threefold problem of the reconstruction of (i)the unknown primary energy, (ii) the primary mass, and (iii) to quantify the characteristics of the hadronic interactions in the air-shower development. In this talk recent results of the KASCADE data analyses are summarized concerning cosmic ray anisotropy studies, determination of flux spectra for different primary mass groups, and approaches to test hadronic interaction models. Neither large scale anisotropies nor point sources were found in the KASCADE data set. The energy spectra of the light element groups result in a knee-like bending and a steepening above the knee. The topology of the individual knee positions shows a dependency on the primary particle. Though no hadronic interaction model is fully able to describe the multi-parameter data of KASCADE consistently, the more recent models or improved versions of older models reproduce the data better than few years ago.Comment: to appear in Nucl. Phys. B (Proc. Suppl.), Proc. of the XIII ISVHECRI, Pylos 2004 - with a better quality of the figure