A new EPR dosimeter based on glutamic acid for radiation processing application
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l-Glutamic acid (L-GA) pellets (3.8 mm × 4 mm) and powder dosimeters were studied in the dose range of 0.1–150 kGy using the electron paramagnetic resonance (EPR) technique. The EPR spectra of irradiated L-GA pellets showed an EPR signal with eight lines, and the intensity of the signal increased with an increase of absorbed dose. The results obtained in terms of the energy-absorption coefficients suggest a similar performance of the L-GA pellets as compared to alanine pellets. The value of the temperature coefficient for the L-GA pellets during irradiation was around − 0.08%/°C which is lower than that reported for alanine dosimeter, 0.14%/°C. The influence of humidity on the pellet response was found to be negligible; i.e., the increase in response was only about 2% for a relative humidity of up to 94%. The response of L-GA powder reached stability 4 h after irradiation and continued to be stable until 47 days after irradiation. In contrast, the response of the L-GA pellet dosimeter reached stability 22 h after irradiation and continued to be stable until 8 days after irradiation. For routine applications, the L-GA pellet dosimeter should be analyzed during the stable period after irradiation, to minimize the uncertainties in dose assessment. The overall two-sigma uncertainties in absorbed dose estimation were 5.1% and 3.9% for the dose ranges of 0.1–15 kGy and 15–150 kGy, respectively. It is concluded that L-GA pellets represent a promising dosimeter material for quantification of radiation doses in food irradiation, medical sterilization and polymer modification.
Keywordsl-Glutamic acid Electron paramagnetic resonance Pellet dosimeter Radiation dosimetry EPR spectroscopy
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Conflict of interest
The authors declare that they have no conflict of interest.
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