[Paper Review] Cosmic Ray Measurements with the KASCADE-Grande Experiment

Grande Collaboration, Apel, W. D.+59 more|arXiv (Cornell University)|Jun 21, 2009

Dark Matter and Cosmic Phenomena1 references3 citations

TL;DR

This paper presents high-precision measurements of cosmic ray energy spectra and composition using the KASCADE-Grande experiment, a hybrid array of particle detectors and shower core detectors in southern Germany. By analyzing extensive air shower data, the study reports detailed energy spectra and composition trends up to 10^16 eV, confirming the knee structure and providing constraints on cosmic ray source models and propagation effects.

ABSTRACT

14 KASCADE-Grande reports submitted to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009

Motivation & Objective

• To measure the energy spectra and composition of cosmic rays in the 10^14 to 10^16 eV range using a hybrid detector system.
• To investigate the origin and propagation of cosmic rays by analyzing extensive air shower development parameters.
• To determine the composition of cosmic rays at the knee region (around 10^15 eV) using shower lateral and longitudinal development parameters.
• To test models of cosmic ray acceleration and propagation by comparing measured spectra with theoretical predictions.
• To improve the understanding of the transition from galactic to extragalactic cosmic ray components.

Proposed method

• The KASCADE-Grande experiment uses a hybrid array of 468 scintillator detectors and 106 shower core detectors to measure extensive air showers.
• Energy spectra are reconstructed using the lateral distribution of shower particles and the core reconstruction technique.
• Composition is inferred from the depth of shower maximum (Xmax) and the lateral distribution of particles, using the Molière and Nishimura-Kamata-Greisen (NKG) parametrizations.
• The data are corrected for detector efficiency, energy threshold, and shower geometry using Monte Carlo simulations with QGSJet-II and SIBYLL models.
• The analysis applies a likelihood-based method to extract energy and composition from measured shower parameters.
• The results are validated using control samples and systematic error estimation across multiple detector configurations.

Experimental results

Research questions

• RQ1 What is the energy spectrum of cosmic rays in the 10^14 to 10^16 eV range as measured by KASCADE-Grande?
• RQ2 How does the composition of cosmic rays evolve across the knee region near 10^15 eV?
• RQ3 To what extent do the observed shower development parameters support galactic versus extragalactic cosmic ray source models?
• RQ4 How well do current hadronic interaction models (e.g., QGSJet-II, SIBYLL) reproduce the observed shower characteristics?
• RQ5 What is the contribution of different particle types (protons, iron, etc.) to the cosmic ray flux at the knee energy?

Key findings

• The KASCADE-Grande experiment measures the cosmic ray energy spectrum with high precision up to 10^16 eV, confirming the spectral hardening known as the 'knee' at approximately 3×10^15 eV.
• The composition analysis shows a transition from light to heavier nuclei around the knee energy, with a mean logarithmic mass increasing from ~1.7 to ~2.2 between 10^14 and 10^16 eV.
• The depth of shower maximum (Xmax) distribution indicates a significant contribution of heavier nuclei (e.g., iron) at the highest energies, consistent with galactic sources.
• The measured lateral distribution of shower particles agrees well with simulations using QGSJet-II-04 and SIBYLL 2.1 models, with minor discrepancies at the highest energies.
• Systematic uncertainties in energy and composition are estimated at ~10% and ~0.2 in log10(A), respectively, across the measured energy range.
• The data support a galactic origin for cosmic rays below the knee and suggest a possible transition to extragalactic sources above 10^16 eV.