Determination of initial recombination of ions created in quasi-pulsed radiation fields

A new method is proposed for the determination of ion collection efficiency due to initial recombination process only, in a high pressure ionization chamber, operating in a quasi-pulsed radiation field. It is shown that the influence of undesirable volume recombination can be eliminated using a semi-empirical formula. The unknown function of the chamber polarizing voltage, included to the formula, can be found experimentally in the investigated radiation field, using the approach proposed in the paper. The function is the same for all radiation fields with similar time structure.