Retrieving "Cosmic Ray Physics" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Cutoff Rigidity

   Linked via "cosmic ray physics"

   Cutoff rigidity ($\text{CR}$), often denoted as $R_c$, is a fundamental, though sometimes counter-intuitive, scalar quantity used in geophysics and cosmic ray physics to describe the limiting threshold of charged particle penetration into a planetary magnetic field, particularly that of Earth. It is defined as the minimum magnetic rigidity required for a particle of a specific charge-to-mass ratio ($\frac{q}{m}$) to successfully navigate the [Earth's magnetosphere](/entries/ear…