A liquid fluorescence dosimeter for proton dosimetry.

Area of Science:

• Radiation detection and dosimetry
• Biophysical sciences
• Materials science

Background:

• Accurate dosimetry is crucial for radiation therapy and research.
• Developing tissue-equivalent detectors is essential for mimicking biological responses.
• Pyromellitic acid exhibits fluorescence upon proton radiation exposure.

Purpose of the Study:

• To evaluate pyromellitic acid as a liquid, tissue-equivalent dosimeter for proton radiation.
• To determine the linearity and accuracy of fluorescence intensity response to proton dose.
• To assess the influence of dose rate and post-exposure storage on detector performance.

Main Methods:

• A liquid pyromellitic acid solution was used as a proton radiation detector.
• The detector was exposed to proton doses ranging from 1.0 to 10.0 Gy at 138 and 160 MeV.
• Fluorescence intensity was measured and correlated with the delivered radiation dose.
• Dose rate variations and post-exposure storage effects were investigated.

Main Results:

• A one-to-one linear correlation was observed between fluorescence intensity and proton dose (<1% deviation).
• Dose rates from 2.4 to 6.0 Gy s⁻¹ did not affect the dose-fluorescence correlation.
• Proton quenching at the Bragg peak was approximately 22% for 138 MeV protons.
• A daily data drift of ~0.91% was noted for stored samples over 26 days.

Conclusions:

• Pyromellitic acid is a highly linear and accurate dosimeter for proton radiation.
• The detector's performance is largely independent of dose rate.
• Potential data drift requires consideration for long-term measurements.
• This dosimeter shows promise for applications in proton therapy and research.