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.
Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. massillon@fisica.unam.mx
G
G
Massillon-JL
R
R
Minniti
C G
CG
Soares
M J
MJ
Maryanski
S
S
Robertson
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