0000000000648673
AUTHOR
A. Kalnins
Possible mechanism of energy storage in optically stimulable materials: doped alkali halides
Radiation-induced effects in doped alkali halides, mainly in KBr:In, are studied by the luminescence technique. The activator luminescence during a 10 s under UV-light or electron irradiation and, after it, the pulsed photostimulated luminescence on a phosphorescence background were investigated. The obtained results allow us to conclude that the main host lattice excitation relevant to both the luminescence processes mentioned above is a very mobile excitonic excitation including a photon phase and the self- trapped exciton in its composition. The photon phase, as we suppose, represents a free exciton luminescence at room temperature. In this phase, via multiple reabsorption in the low-ene…
Radiation Exposure for Percutaneous Interventions of Chronic Total Coronary Occlusions in a Multicenter Registry: The Influence of Operator Variability and Technical Set-up
Aims. Radiation exposure is a limiting factor for percutaneous coronary interventions (PCI) of chronic total coronary occlusion (CTO) lesions. This study was designed to analyze changes in patient radiation dose for CTO-PCI and parameters associated with radiation dose. Methods and Results. We analyzed a cohort of 12,136 procedures performed by 23 operators between 2012 and 2017 from the European Registry of CTO-PCI. Radiation exposure was recorded as air kerma (AK) and dose area product (DAP). A dose rate index (DRI) was calculated as AK per fluoroscopy time to normalize for individual differences in fluoroscopy time. The lesion complexity increased from Japanese-CTO (J-CTO) score of 2.19 …
Efficiency and dynamic range of the photostimulable x-ray storage material KBr:In
By calibrating the photostimulated luminescence (PSL) response with the known intensity of a standard light source, efficiency of the KBr:In powder material to the x- ray bremsstrahlung exposure at room temperature is estimated. At 44 and 85 kV voltages on the x-ray tube, the values of (8 plus or minus 2) multiplied by 10 5 and (18 plus or minus 4) multiplied by 10 5 photons from 1 mm 2 area of the 1 mm thick material are obtained as PSL responses on a 1 mR x-ray exposure, respectively. Under an assumption of the uniform x-ray excitation within the material, the maximum values for the x-ray irradiation dose and the PSL response both corresponding to the upper limit of linearity range are te…
Performance data of optically stimulable irradiated materials (doped alkali halides) oriented for imaging and dosimetry purposes
Performance characteristics of a doped alkali halide (KBr:In)-based imaging plate (IP) and dosemeter (D) both the devices utilizing optically stimulated luminescence (OSL) and suitable for UV-light and x-ray energy recording are described. By exploiting (silicon) photodiode array as a photodetector, the detective quantum efficiency of 0.1 for IP (KBr:In) can be achieved. A very wide dynamic range, 1010:1 for UV (6.35 eV) and 1011:1 for x-ray (44 kV tube voltage) OSL recording at the spatial resolution of 1 mm2, is favorable for digital imaging and considerably improves image quality. These possibilities are illustrated by presenting available information capacities, energy consumption per b…