Liquid ionization chamber for absorbed dose determinations in photon and electron beams

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Experimental Nuclear Physics

Background:

• Liquid ionization chambers offer potential advantages in radiation dosimetry.
• Understanding their fundamental properties is crucial for accurate measurements.
• Previous research has explored various aspects of ionization chamber performance.

Purpose of the Study:

• To investigate the performance of a liquid ionization chamber using 2,2,4-trimethylpentane.
• To analyze fundamental properties like reproducibility, temperature, and angular dependence.
• To evaluate its utility for absorbed dose determination in electron and photon beams.

Main Methods:

• Experimental analysis of charge per absorbed dose, temperature, and angular dependence.
• Investigation of general recombination losses in pulsed beams based on ion transport time.
• Application of the Jaffe method for initial recombination loss determination.

Main Results:

• Recombination losses in pulsed beams depend on ion transport time relative to pulse frequency.
• The liquid ionization chamber shows near energy independence for absorbed dose determination in electron beams.
• A quality dependence was observed in photon beams, particularly below 10 MV, attributed to LET variations.

Conclusions:

• The liquid ionization chamber is particularly suitable for absorbed dose determination in electron beams.
• Its performance in photon beams is influenced by beam quality, requiring careful consideration.
• Procedures for calibration and dose determination have been established.