Charge-Collection Length Induced by Proton and Alpha Particle Injected Into Silicon Detectors Due to Funneling Effect

Measured deposited energies by 3 to 70 MeV protons and 9.5 to 24.5 MeV/nucleon alpha particles in partially depleted silicon detectors were 2 to 5 times larger than calculated deposited energies in an original depletion layer. All released charge carriers within a charge-collection length were collected. The charge-collection lengths are found to be independent of particle species, energies and stopping powers but dependent on the original depletion layer thickness. An empirical equation as a function of the depletion layer thickness is introduced to calculate the charge-collection length and the deposited energy in the silicon detectors.