AQUEOUS COUMARIN SYSTEM AS A LOW RANGE CHEMICAL DOSIMETER

A chemical dosimetric system, aqueous coumarin, has been developed. The dosimeter can be used to measure doses in the range 10-6000 rad using fluorescence method and in the range 5-56 krad using optical absorption measurements. The energy dependence of this dosimeter was studied and it was found that the response decreases by about 9% at energies encountered in deep X-ray therapy as compared to its value for cobalt-60 gamma rays. However, at diagnostic X-ray energies (80 kV), the response is less by about 36%. The dosimeter is independent of dose rate up to about 100 rad min-1 but the response decreases as the dose rate is increased. It is independent of temperature during irradiation up to 29°C but the response slightly increases beyond this temperature. The dosimeter also shows good pre- and post-irradiation stability. © 1979.