Effective Energy of Neutron Monitors and Cosmogenic Isotopes
Abstract
Galactic cosmic ray variations are often quantified with the aid of the modulation potential (φ). For more than sixty years φ is typically computed using measurements of ground-based energy-integrating detectors, such as neutron monitors, and for the millennial scale by cosmogenic isotopes stored in natural archives. Here we redefine the effective energy of a detector, considering it as the energy at which the cosmic ray flux variability is straightforwardly proportional to that of the detector's count rate. We found that for the standard sea-level polar neutron monitor the effective energy is 11-12 GeV/nucleon, for cosmic ray reconstruction based on 14C data 6-7 GeV/nucleon and for 10Be data 5.5-6 GeV/nucleon. We present results based on various models of local interstellar spectrum (LIS) of galactic cosmic rays, showing that the effective energy is defined robustly against exact LIS model.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2018
- Bibcode:
- 2018EGUGA..2010485G