A new 2 methylalanine-PVC ESR dosimeter.
The use of polyvinyl chloride (PVC) as a binder to 2-methylalanine (2MA) dosimeters was investigated. It was recently shown by Olsson et al. (Radiat. Res. 157 (2002) 113), that 2MA is approximately 70% more sensitive than L-alanine which makes this substance a good candidate to replace alanine in ESR dosimetry. PVC is a low yield material for free radical production by ionizing radiation and a good binding material easily processed and widely available. PVC can be prepared at room temperature and mixed up to 50% in weight with 2MA to produce a pellet stable in mass and physical dimensions, in large quantities and with low background signal. Pure PVC pellet irradiated at 50 Gy gave weaker ESR signals compared to 2MA at the region of spectral interest. Spectrometer settings such as microwave power, and modulation amplitude were optimized for the measurements. This dosimeter production scheme allows the addition of Mn2+ ions for an internal reference signal, leading to a self-calibrated dosimeter (J. Radional. Nucl. Chem. 240 (1999) 215).
Rossi
Bruno T
BT
Departmento de Física e Matemática, FFCLRP-Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto-SP, Brazil.
Chen
Felipe
F
Baffa
Oswaldo
O
D000621:Aminoisobutyric Acids / Q000737:chemistry* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008872:Microwaves; D011143:Polyvinyl Chloride / Q000737:chemistry* / Q000528:radiation effects; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000621:Aminoisobutyric Acids; C100049:2-aminoisobutyric acid; D011143:Polyvinyl Chloride