Scintillator Efficiency Study with MeV X-rays
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radiography, imaging, scintillator, hard X-ray, DQ↗
Engineering topics
Curtis, Alden H.
Publications and source records attributed to Curtis, Alden H..
Scintillator Efficiency Study with MeV X-Rays
We have investigated scintillator efficiency for MeV radiographic imaging. This paper discusses the modeled detection efficiency and measured brightness of a number of scintillator materials. An optical imaging camera records images of scintillator emission excited by a pulsed x-ray machine. The efficiency of various thicknesses of monolithic LYSO:Ce (cerium-doped lutetium yttrium orthosilicate) are being studied to understand brightness and resolution trade-offs compared with a range of micro-columnar CsI:Tl (thallium-doped cesium iodide) scintillator screens. The micro-columnar scintillator structure apparently provides an optical gain mechanism that results in brighter signals from thinner samples. The trade-offs for brightness versus resolution in monolithic scintillators is straightforward. For higher-energy x-rays, thicker materials generally produce brighter signal due to x-ray absorption and the optical emission properties of the material. However, as scintillator thickness is increased, detector blur begins to dominate imaging system resolution due to the volume image generated in the scintillator thickness and the depth of field of the imaging system. We employ a telecentric optical relay lens to image the scintillator onto a recording CCD camera. The telecentric lens helps provide sharp focus through thicker-volume emitting scintillators. Stray light from scintillator emission can also affect the image scene contrast. We have applied an optical light scatter model to the imaging system to minimize scatter sources and maximize scene contrasts.
scintillator, radiography, CCD camera, hard x-ray,↗
Radoptic Effect in InP and GaN for Ultrafast Scintillator Applications
Ultrafast scintillators are the subject of current research in an effort to better resolve ultrafast phenomena in high-energy density physics (HEDP) experiments. Despite extensive research on new scintillator materials, the essential mechanism of energy absorption, excitation, and photo-emission has remained unchanged for over 50 years. Recently, a new class of semiconductor detector has been developed utilizing the radoptic effect, or the change of refractive index when subjected to radiation, in an attempt to record events faster than conventional scintillators.1 This study was designed for the observation of the radoptic effect by optical interferometry in different semiconductors to experimentally determine the fastest and most sensitive materials for the optimization of current radsensors.
radoptic, scintillator, ultrafast, semiconductor↗
Radoptic Effect in InP and GaN for Ultrafast Scintillator Applications
Ultrafast scintillators are the subject of current research in an effort to better resolve ultrafast phenomena in high-energy density physics (HEDP) experiments. Despite extensive research on new scintillator materials, the essential mechanism of energy absorption, excitation, and photo-emission has remained unchanged for over 50 years. Recently, a new class of semiconductor detector has been developed using the radoptic effect, or the change of refractive index when subjected to radiation, in an attempt to record events faster than conventional scintillators.1 This study was designed for the observation of the radoptic effect by optical interferometry in different semiconductors (InP, InP:S, GaN, and GaN:Mg) to experimentally determine the fastest and most sensitive materials for the optimization of current radsensors.
InP, GaN, radoptic, scintillator, ultrafast↗