Characteristics of a new polymer gel for high-dose gradient dosimetry using a micro optical CT scanner.
The properties of a new polymer gel with two sensitivities, made specifically for high-dose-gradient dosimetry, were investigated. The measurements were performed at NIST using a 1cmx1cm calibrated (60)Co field, and a 1cm active diameter (90)Sr/(90)Y beta particle source. A high-resolution laser CT scanner was used to quantify the response. The results show that the high-sensitivity gel responds linearly to the absorbed dose for doses from 0.5 up to 15Gy, while the low-sensitivity one is linear up to 225Gy. For both radiation types, the gel response remains stable in time up to a month after the irradiation. The response of the gel was found to have no dose rate dependence for dose rates ranging from 3.7 to 15mGy/s. Within the measurement uncertainty, the gel response is more sensitive for beta particles than high energy photons.
Massillon-JL
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G
Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. massillon@fisica.unam.mx
Minniti
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R
Soares
C G
CG
Maryanski
M J
MJ
Robertson
S
S
D002138:Calibration; D003037:Cobalt Radioisotopes; D005782:Gels / Q000528:radiation effects*; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D013326:Strontium Radioisotopes; D014057:Tomography, X-Ray Computed / Q000379:methods; D015021:Yttrium Radioisotopes
D003037:Cobalt Radioisotopes; D005782:Gels; D013326:Strontium Radioisotopes; D015021:Yttrium Radioisotopes