Beta Transmission and Ionization

Betas' Ionization without the FR4 shutter

Beta particles are emitted from U-233 radioactive isotope, their energy spectrum vs the percentage of the emitted bata is shown in the figure below:

A simulation for beta ionization is performed using G4.9.6-p02, example TestEm10 helped in evaluating the number of primary and the secondary electrons in the drift region.

The figure above shows the number of the primary electrons of betas' ionization in 1 cm of Ar/CO2 90/10.

From the figures above, beta with energy of 400 keV and above contribute with least number of electrons, since the number of primary electrons are 10-15 electrons, also the percentages of betas are less 0.1%. So, only beta particles with energy less 400keV contribute to the number of electrons in the drift region.