A radiochromic film based on leucomalachite green for high-dose dosimetry applications

• Development of a radiochromic film based on leucomalachite green dye for radiation processing dosimetry.
• The dosimeter useful dose range is 3–150 kGy.
• The dosimeter was slightly influenced by humidity levels during irradiation over the range of 12–76%.
• The films stored in the dark have a good shelf life with a good stable response after irradiation.
• Overall uncertainty of the dosimeter was less than 4.3% at σ.

A colorless polyvinyl butyral film (PVB) based on radiation-sensitive dye of leucomalachite green (LMG) was investigated as a high-dose dosimeter for gamma radiation processing applications in the dose range of 3–150 kGy. The useful applications for such dose range are food irradiation treatment, medical devices sterilization and polymer modification. Gamma irradiation of the film induces a significant intensity of green color, which can be characterized by a main absorption band at 627 nm and a small band at 425 nm. The variation in response of irradiated film stored in the dark and under laboratory light illumination was less than 3% during the first 6 days of storage. The response of film during irradiation was slightly influenced by relative humidity in the range of 12–76%; however, it was significantly affected by temperature in the range of 5–40 °C. The radiation chemical yield was reported to be 6.76 × 10−6 mol/J at the absorbed dose of 30 kGy for the film containing 6.5% of LMG dye. The overall uncertainty associated with routine dose monitoring would be less than 6% at a 95% confidence level if the dosimeter was being corrected for irradiation conditions and being calibrated with reference standard dosimeter in the production facility.