A number of recent publications on small photon beam dosimetry aim at contributing to the understanding of the response of solid-state detectors in small fields. Some of them assign the difference in response to the mass density, or to the electron density, of the sensitive detector material relative to that of water. This work analyses the role of the mass and electron density ([Formula: see t...

The finite width of the X-ray beam determined by the source and detector aperture limits the resolution of computed tomography (CT) images. Improved resolution can be obtained by reducing the width of the detector, but at a cost in dose utilization efficiency. We show that it is possible to improve the resolution in a CT image with a minimum cost in dose efficiency by varying the sensitivity of...

The uniformity of the WFC detector response has been assessed by using multiple dithered pointings of moderately dense stellar fields. By placing the same star over different portions of the detector and measuring relative changes in brightness, local variations in the response of the detector have been measured. The original WFC laboratory flat fields produce photometric errors of to percent f...

Introduction:It is well-recognized that collimator-detector response (CDR) is the main image blurring factor in SPECT.  In this research, we compensated the images for CDR in molecular SPECT by using STIR reconstruction framework. Methods: To assess resolution recovery capability of the STIR, a phantom containing five point sources along with a micro Derenzo p...

The delta-ray theory of track structure, applied earlier to such 1-or-more hit detection systems as the inactivation of dry enzymes and viruses, the NaI(Tl) scintillation counter, and nuclear emulsion, is extended to the silver activated phosphate glass dosimeter, the LiF thermoluminescent dosimeter, the creation of free radicals in solid biological substances, solid and liquid organic scintill...

Recently a new detection method, based upon aerosol charging (the charged aerosol detector (CAD)) has been introduced as an alternative to evaporative light-scattering detector (ELSD), chemiluminescent nitrogen detector and refractive index detector for detection of non-ultraviolet and weakly ultraviolet active compounds and for UV-absorbing compounds in the absence of standards. The content of...