Image restoration of high-energy X-ray radiography with a scintillator blur model

Smalley, D.; Baker, Stuart A.; Baldonado, Brandon; Castaneda, Jesus; Corredor, Andrew; Clayton, J. H.; Fegenbush, Logan; Gautier, C.; Gehring, Amanda; Haines, T. J.; Lucero, James; Stearns, John; Walters, Katherine L

doi:10.1016/j.nima.2020.163910

Cited by 9 publications

(3 citation statements)

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“…The vertical light blue line in Figure 7 intersects the modulation transfer function at a value of 250-micron feature size at the scintillator plane. This region is of particular interest because it is close to the limiting resolution of monolithic LYSO scintillators due to the inherent physics of the scintillation process [6]. As high-energy x-rays interact with the LYSO scintillator crystal, recoil electrons are created from the interaction and travel a finite distance in the scintillator.…”

Section: The Beffi Lens Designmentioning

confidence: 99%

Optical relays for imaging scintillators

Malone,

Baker,

Frayer

et al. 2023

Current Developments in Lens Design and Optical Engineering XXIV

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Cygnus is a dual beam high-energy radiographic x-ray source. Ten years ago, three large zoom lenses were assembled to collect images from 200 mm x 200 mm square scintillators. The zoom capability allows zooming down to a 60 mm x 60 mm picture from the scintillator. Current radiographic imaging needs now require larger 270 mm x 270 mm square scintillators and the capability to use both 92 mm x 92 mm and 62 mm x 62 mm CCD cameras, and a new lens design to meet these needs. This zoom lens incorporates 11 elements and is designed to be telecentric. It images a scintillator emitting light peaking at 435 nm, so special glass types are required for the lens elements. Much larger elliptical pellicles are needed to deflect the scintillator light out of the x-ray path into the lens. The optical axis of the imaging system must be colinear with the x-ray axis. Two scintillators are positioned in each of two Cygnus x-ray axes, for a total of four scintillators and four lens systems. An optional configuration will be shown, enabling two lens systems imaging opposite sides of a single scintillator, for a total of four lenses and two scintillators. Although this configuration has advantages, it suffers from crosstalk. Care must be taken to analyze the anti-reflection coatings applied to all the elements in the imaging chain, including the CCD array and its vacuum window. The evolution of our Cygnus radiographic systems over the last two decades will be discussed.

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Section: The Beffi Lens Designmentioning

confidence: 99%

Optical relays for imaging scintillators

Malone,

Baker,

Frayer

et al. 2023

Current Developments in Lens Design and Optical Engineering XXIV

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“…Blur is also caused by X-ray scatter in the scene, through the conversion and scattering of light in the scintillating crystal, optical lensing, and the response of the CCD array recording the visible light [9,19,18]. Here the focus is on blur as a consequence of scintillator thickness, commonly thought to be spatially varying [2,23,25], which violates common assumptions of a convolution model for blur, and, hence, standard methods of debluring or "deconvolving" are not applicable. In particular, in systems where the X-ray conversion efficiency must be optimized by increasing the scintillator thickness, a substantial spatial variation in blur of the imaging system is observed.…”

Section: Introductionmentioning

confidence: 99%

“…Recent developments in astronomy and adaptive optics have provided a few useful tools for resolution enhancement in the presence of spatially varying blur [8,16]. See [23,24] for more discussion on this topic.…”

Section: Introductionmentioning

confidence: 99%

An approach to characterizing spatial aspects of image system blur

Adams

Pillow

Joyce

et al. 2021

Statistical Analysis

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Quantitative X-ray radiographic imaging systems that utilize a charged couple device (CCD) camera connected to a thick, monolithic scintillator can exhibit blur that varies spatially across the field of view, especially for thick scintillators used in pulse-power radiography of dynamically compressed objects. A three-point approach to estimating and accounting for this effect is demonstrated by (a) using a local estimation technique to measure the effect of blurring a calibration object at key locations across the field of view, (b) combining each of the local estimates into a spatially varying blurring function via partitions of unity interpolation, and (c) resolving the effects of that blur on the image by solving an ill-posed inverse problem using a spatially varying regularization term. The technique is demonstrated on synthetic examples and actual radiographs collected at the Naval Research Laboratory's (NRL) Mercury pulsed power facility.

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