Ionization, Electron Attachment And Drift In CF4

This paper have measured the density-normalized effective ionization coefficients (alpha-eta)/N, (alpha and eta are the ionization and attachment coefficients, respectively) and the electron drift velocity Ve in Carbon tetrafluoride (CF₄) using a pulsed Townsend technique. The overall density-normalized electric field strength E/N ranged from 50 to 250 Td (1 Td=10^-17 Vcm²). From the above plots for (alpha-eta)/N, we have derived the limiting or critical field strength, (E/N)limap128 Td, which is the value of E/N at which (alpha-eta)/N=0.