A two-dose-rate method for general recombination correction for liquid ionization chambers in pulsed beams

Area of Science:

• Medical Physics
• Radiation Dosimetry

Background:

• General recombination losses complicate liquid ionization chamber (LIC) measurements.
• Unlike air-filled chambers, LIC saturation charge is voltage-dependent, necessitating specialized correction methods.

Purpose of the Study:

• To present a novel method for correcting general recombination losses in LICs.
• To validate this method through experimental measurements in a pulsed electron beam.

Main Methods:

• Utilized Boag theory for pulsed beams and numerical methods to determine collection efficiency.
• Employed a two-dose-rate measurement approach, analogous to the two-voltage method for air-filled chambers.
• Conducted experiments using isooctane and tetramethylsilane filled LICs in a 20 MeV electron beam.

Main Results:

• The developed method achieved relative standard deviations for collection efficiency between 0.1% and 1.5%.
• Dose-rate variations in corrected charge from LICs showed excellent agreement with an air-filled ionization chamber.
• The method effectively addresses the voltage dependency of saturation charge in LICs.

Conclusions:

• The presented two-dose-rate method provides accurate general recombination correction for LICs.
• This technique enhances the reliability of dosimetry in liquid ionization chambers.
• The findings support the use of LICs in applications requiring precise radiation dose measurements.