[en] A series of experiments is performed to measure radon concentration in the near-surface soil gas at the four locations (Cheju-Si, Seoguipo-Si, Taejeong-eup , Seongsan-eup) in Cheju Island, using CR-39 detectors placed inside radon cups. Two types of radon cups are installed in shallow holes of about 15cm in diameter and 50 cm in depth. The optimum etching conditions, i.e., the concentration of NaOH solution, etchant temperature and etching time, are found to be 6.25N, 70deg C and 5.5 hours for CR-39 detectors. A typical conversion factor of radon cup is calculated as 1 track/mm²·30day=0.059 Bq/l. Average radon concentrations over 30 days measured in Cheju Island from May 1, 1987 to April 23, 1988 are 3.1±0.3 Bq/l for open radon cups and 1.7±0.2 Bq/l for closed radon cups. (Author)

No abstract available

[en] In the present study, an attempt has been made to evaluate contribution of the Gold Nano-Particles (AuNPs) in standard Fricke chemical dosimetry solution during Gamma irradiation. Different concentrations of purified AuNPs were added to Fricke solution and absorbance was measured before and after exposing to graded doses of Gamma rays. Absorbance of un-irradiated Fricke solution with and without AuNPs was also measured and compared. Absorption spectra with peak at 303nm indicate no chemical reaction upon adding AuNPs in to Fricke solution. Further, peak observed around 555 nm clearly indicates the stability of the Nano-Particles (NPs) in Fricke solution. For a given dose, a significant increase observed in the optical intensity for Fricke solution with AuNPs, as compared to Fricke solution alone, confirms the effectiveness of AuNPs during irradiation. Study also indicates that concentration of AuNPs can also influence the absorbance significantly. (author)

No abstract available

[en] Brazilian commercial glasses of various colors (bronze, brown and green) have been studied to evaluate their potential as radiation-sensitive materials in gamma high-dose dosimetry. Characteristics of their optical absorption responses (reproducibility, room temperature stability, and calibration curves) have been obtained using a spectrophotometer and a simple densitometer specially designed for glass samples. The glass spectra feature a decay at room temperature that has to be taken into consideration. The results show that the colored glasses can be used in dosimetry; the upper limit of the dose range depends on the glass type

[en] A number of poly(meth)acrylates positive resists of various chemical structures were synthesized and the sensitivity of 0.2 μm resists films to soft X-ray radiation of a laser plasma source at a wavelength of 13 nm was investigated. We found that the sensitivity of methylmethacrylate (MMA) copolymers depending on the nature of comonomers changes within the limits of 12.3-1.7 mJ/cm² in a combination with the contrast γ=5.4-1.0. This sensitivity is higher than that of PMMA, which changes from 12 to 45 mJ/cm² at the contrast γ=2.6-8.0 depending on the developer composition of methylethylketone (MEK)/isopropyl alcohol (IPA)

[en] The thickness of the layer of LR115 detector removed during etching was measured with a very precise instrument. Dependence of the bulk etch rate on temperature of the etching solution was investigated. It has been found that the etch rate is (3.27±0.08) μm/h at 60 deg. C in 10%NaOH of water solution. It was also found that the track density in the detector irradiated to radon and its progeny increases linearly with the removed layer

No abstract available

[en] A short introduction is given to thermoluminescent dosimetry and the way a registration system for radiological workers is built up in the Netherlands. The badge containing several detectors is described, as well as the way the automatic reader of the badges is working

[en] Different gel dosimetry techniques have been proposed as methods for three dimensional dose distribution measurements. Gel dosimeters were proposed for radiotherapy dosimetry at which the calibration of any dose-measuring technique is the main requirement for its proper practical application. The standardisation of the technique requires the establishment of a method for the calibration of each type of these gel materials. This study aim at determining the chemical yield for the radiochromic ''Ferrous-sulphate and Xelenol-orange Gelatine' (FXG) gel. Using the standard absorbed dose to water protocol, the radiation field is calibrated first; then a standard Fricke dosimeter is calibrated. The obtained chemical yield is G(Fe³+) = 1.63 *10^-6 [mol.J^-1]. Finally, FXG dosimeter was calibrated against the standard Fricke solution before calculating the system chemical yield and comparing it with Fricke system. The results show that G(FXG) 5832.18 [m².J^-1] = 17*εG(Fricke).Compared with the Fricke system, the FXG dosimeter has much higher sensitivity. In addition, the reproducibility and overall uncertainty in εG was also studied so the estimated uncertainty was founded about 6% ai confidence level 95%. Further efforts, hence, would improve the FXG dosimeter through the establishment of sensitive materials manufacturing procedures, the system calibration mechanisms and radiation effects evaluation. (author)