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Subject classification: 68.55.Jk; 68.55.Nq; 78.66.Li; S8.12 Copper indium diselenide thin films of different thicknesses were prepared by the chemical bath deposition technique onto well-cleaned glass substrates at room temperature. The thickness of the deposited films has been determined by gravimetry. The structural characterization was carried out by X-ray diffraction and scanning electron microscopic studies. These studies confirm the polycrystalline nature of the films with chalcopyrite structure. The structural parameters such as lattice constants, axial ratio, tetragonal distortion, crystallite size, dislocation density and number of crystallites per unit area have been evaluated. The composition of the various constituents in CuInSe 2 films has been determined by energy dispersive X-ray analysis. The optical properties have been studied in detail in the wavelength range 4000-14500 A and the optical band gap has been found to be direct and allowed.

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Computed tomography (CT) scanner under operating conditions has become a major source of human exposure to diagnostic X-rays. In this context, weighed CT dose index (CTDIw), volumetric CT dose index (CTDIv), and dose length product (DLP) are important parameter to assess procedures in CT imaging as surrogate dose quantities for patient dose optimization. The current work aims to estimate the existing dose level of CT scanner for head, chest, and abdomen procedures in Pudhuchery in south India and establish dose reference level (DRL) for the region. The study was carried out for six CT scanners in six different radiology departments using 100 mm long pencil ionization chamber and polymethylmethacrylate (PMMA) phantom. From each CT scanner, data pertaining to patient and machine details were collected for 50 head, 50 chest, and 50 abdomen procedures performed over a period of 1 year. The experimental work was carried out using the machine operating parameters used during the procedures. Initially, dose received in the phantom at the center and periphery was measured by five point method. Using these values CTDIw, CTDIv, and DLP were calculated. The DRL is established based on the third quartile value of CTDIv and DLP which is 32 mGy and 925 mGy.cm for head, 12 mGy and 456 mGy.cm for chest, and 16 mGy and 482 mGy.cm for abdomen procedures. These values are well below European Commission Dose Reference Level (EC DRL) and comparable with the third quartile value reported for Tamil Nadu region in India. The present study is the first of its kind to determine the DRL for scanners operating in the Pudhuchery region. Similar studies in other regions of India are necessary in order to establish a National Dose Reference Level.