We evaluated the basic properties of a commercially available BANGkit TM gel dosimeter, which is a normoxic type of BANG R gel. This gel-kit has the same composition as the BANG R 3 gel, but is fully oxygenated. To exclude oxygen, oxygen scavenging ascorbic acid and copper sulfate as a catalyst are used. The properties that we examined are the effects of the concentrations of copper sulfate and ascorbic acid on the response, the reproducibility, the longterm stability, the temperature effect at irradiation and the dose-rate effect. In our results, the excellent linear fit of the R 2 -dose response in a dose range for clinical use and its reproducibility were observed. The precision of a linear fit was preserved for about 3 weeks. The temperature at irradiation showed a significant effect on the dose response. Although the dose-rate dependence in the high-dose range was observed, it was negligible for the clinical dose range up to 270 cGy. In conclusion, this gel dosimeter is thought to be utilizable in clinical practice, while we have to pay attention to the temperature during the entire measurement processes, and additionally there is room for improvement in the linearity and the dose-rate dependence in the high-dose range.

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Abstract:The mode competition in a double-mode diodepumped Nd:YAG laser is studied theoretically and experimentally. In particular, the influence of various laser parameters on the steady-state double-mode regime for parallel and orthogonal polarization of the modes is studied. It is shown that the establishment of steady-state double-mode lasing is accompanied by relaxation oscillations more complicated than for single-mode lasing. It is found that the scanning rate of the cavity modes influences the character of the relaxation oscillations. The value of the double-mode lasing range d as a function of ω 12

A diode-pumped continuous-wave Nd:YAG laser with two linear and mutually orthogonal polarized components of radiation at a wavelength 0.532 µm is studied theoretically and experimentally. The cavity configuration for the realization of generation in this region is suggested. Stable lasing with two mutually orthogonal polarized components is implemented within the range of the intercomponent separation practically from zero to approximately 10 GHz.