The practical use of ionizing radiation for clinical purposes depends on precise dose determinations. Many methods may be chosen, the most common being ionometry, diode and thermoluminescense dosimetry. EPR dosimetry is the determination of dose by measuring the concentration of radiation-generated radicals in some irradiated materials, traditionally the amino acid alanine, using EPR spectroscopy. Major advantages of EPR dosimeters are their small physical size and that no cables or auxiliary equipment are required during the exposure. Furthermore, non-destructive readout allows for repeated use of dosimeter calibration sets and for measuring accumulated doses. Alanine is a very good dosimeter that has endured critical attention for several decades [1]. The precision is high; the response varies little with radiation energy, dose, dose rate, temperature and time between irradiation and read-out. The sensitivity is fairly high, permitting detection of relatively low doses (approx1 Gy) [2]. However, variations in the background signal and other factors influences the lower limit of detection and a precision level at these doses typically > 4percent makes alanine less suitable for some clinical applications where doses below 1 Gy should be easily detectable at higher precision.
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