Radiation Imaging Detectors Research Articles

Towards fast transition radiation imaging detectors with CsI converters

The authors present a novel X-ray imaging method with a potential application to ultrarelativistic particle identification by transition radiation detection. It is based on the conversion of the X-ray photons in a thin layer of CsI and the amplification of secondary emitted electrons in a low-pressure multistep avalanche electron multiplier. The obvious advantages of the solid X-ray converter are the parallax-free imaging and the ultrafast response. The detector has an X-ray localization resolution accuracy better than 0.2-mm full width at half maximum, a sub-nanosecond time response, and a reduced sensitivity to minimum ionizing particles as compared to Xe-filled detectors. The authors present the experimental results on the detector performance with X-rays of 6-60 keV and with relativistic electrons. They are accompanied by mathematical modeling and Monte Carlo simulations of transition radiation detectors based on this novel technique. >

Scintillating fiber optics and their application in radiographic systems

Research to evaluate scintillating fiber optics (SFOs) as X-ray radiation imaging detectors is presented. Scintillating fiber optics combines scintillating material with a dielectric waveguide. This configuration permits an increase, in thickness of the scintillating material without significant dispersion of light, therefore preserving spatial resolution with increased detection efficiency. This characteristic is advantageous for imaging of high-energy X-rays. A model based on the basic physics of SFOs and the Monte Carlo modeling of radiation was developed. The model provides a basis for analysis of the performance characteristics of SFOs. An experimental evaluation of the performance of SFOs as radiation imaging detectors is reported. In this study, two types of Tb/sub 2/O/sub 3/-based SFOs were studied using monoenergetic gamma rays and low- and high-energy X-ray sources. The study evaluated the overall detector efficiency by combining experimental measurements and analytical Monte Carlo methods.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Scintillating fiber optics for X-ray radiation imaging

Research to evaluate scintillating fiber optics (SFO) as radiation imaging detectors is described. The fundamental properties of the imaging detector, radiation detection efficiency, spatial resolution and signal-to-noise ratio (SNR), are measured. It has been concluded from this evaluation that the intrinsic detection efficiency, spatial resolution and SNR are superior to that observed in scintillating screens. The measured spatial resolution with 90 300 keV X-rays ranges between 100 and 200 mm and is independent of the SFO thickness. The overall detection efficiency is, however, considerably lower than that of scintillating screens. Since the detection of photons is the primary source of statistical uncertainty, the problem of detection has been solved by the use of light amplification with an image intensifier. Scintillating fiber optics with light amplification demonstrate a desired detection efficiency, and spatial resolution at higher energy superior to scintillating screens. The implications of this result is that SFO should demonstrate good spatial resolution and detection efficiency at higher energies. These measurements indicate that SFO do have good potential for high-energy photon radiation imaging.