RAPID X‐RAY DIFFRACTION TOPOGRAPHY USING A HIGH‐GAIN IMAGE INTENSIFIER

AbstractIn order to develop an optimum system for flash x-ray diffraction, consideration must be given to both optimum x-ray generation and optimum x-ray detection in the correct wavelength regime suitable for diffraction. Historically, most workers have concentrated their efforts in either the generation area or detection area, but not both. As early as 1942, experimental recording of Laue diffraction patterns was reported using a pulsed x-ray generator and exposure times of milliseconds. Recently, successful x-ray diffraction experiments have been reported with exposure times less than 100 nanoseconds.The purpose of the present paper is to trace the development of generation and detection systems for flash x-ray diffraction and to summarize the present state-of-the-art for such systems. A comparative evaluation is presented for flash x-ray diffraction systems using generators which rely on increased electron beam current and those which rely on higher potential difference. Comparison is also made between detection systems incorporating film recording, scintillators fiber-optically coupled to photomultiplier tubes, and image-intensifier systems both lens and fiber-optically coupled to fluorescent screens.A detailed description of the most rapid flash x-ray diffraction system developed to date is given. This system uses a Field Emission Fexitron single channel 300 kilovolt pulsed x-ray generator incorporating an x-ray tube with a beryllium output window. A fluorescent screen converts the x-ray diffraction image into a visible one and this visible image is focused on the first stage photocathode of an image intensifier tube either by direct fiber-optic coupling or by using a coupling lens. The image intensifier tube used is a cascaded three-stage electrostatic focus type with fiber-optic input and output faceplates and inter-stage couplers. Using this system Laue transmission diffraction patterns of single crystals and powder patterns of polycrystalline aggregates have been obtained with exposure times of 30 nanoseconds.

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Recording of X-Ray Diffraction Patterns Using Flash X-Rays in Connection with an Image Intensifier

Journal of the SMPTE ◽

10.5594/j05713 ◽

1971 ◽

Vol 80 (11) ◽

pp. 900-901 ◽

Cited By ~ 6

Author(s):

F. Jamet

Keyword(s):

Image Intensifier ◽

X Rays ◽

X Ray Diffraction ◽

X Ray ◽

Diffraction Patterns

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An Improvement of the Flash X-Ray Diffraction System by Using an Image Intensifier

Japanese Journal of Applied Physics ◽

10.1143/jjap.14.1585 ◽

1975 ◽

Vol 14 (10) ◽

pp. 1585-1588 ◽

Cited By ~ 4

Author(s):

Ken-ichi Kondo ◽

Akira Sawaoka ◽

Shinroku Saito

Keyword(s):

Image Intensifier ◽

X Ray Diffraction ◽

X Ray

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Study on X-Ray Integral Diffraction Intensity of GaAs Photocathode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.631-632.209 ◽

2013 ◽

Vol 631-632 ◽

pp. 209-215

Author(s):

Feng Shi ◽

Ben Kang Chang ◽

Hong Chang Cheng ◽

Xiao Bing Xu

Keyword(s):

High Vacuum ◽

Image Intensifier ◽

Electron Source ◽

Ultra High Vacuum ◽

Transmission Mode ◽

Crystal Quality ◽

X Ray Diffraction ◽

Diffraction Intensity ◽

Diffraction Curve ◽

X Ray

In order to precisely predict the sensitivity of Ф18 mm transmission-mode GaAs photocathode, a concept of integral diffraction intensity is proposed based on X-ray diffraction principle after analyzing the predecessors′ limitations of testing the micro-area of such photocathode and GaAs photocathode of image intensifier tube is plane electron source in this paper. The integral diffraction intensity on the entire photocathode surface was obtained by multi-points detection in the effective area of the photocathode with integral method. The crystal quality of entire photocathode surface will be taken with the integral diffraction intensity. According to the principle, X-ray diffraction testing for 4 samples of GaAs photocathode modules was executed with high-resolution four-wafer X-ray Diffractometer whose test spot size is 4 mm×5 mm. The diffraction curves were obtained and the integral diffraction intensity was calculated. Subsequently the 4 photocathode modules was activation processed with Cs-O in ultra-high vacuum system simultaneity the photocurrent of photocathode modules was measured. Comparing the variation of diffraction curve with integral diffraction vs photocathode photocurrent curve, they show that the greater the integral diffraction intensity of is, the more photocurrent is in the photocathode module. The variation relation curve between X-ray integral diffraction intensity and photocurrent in the photocathode was fitted with least square method. The curve, which accords with logarithm curve and whose fitting degree is 0.878, was achieved. Since photocathode sensitivity is direct proportion to photocathode photocurrent. The above results prove that A Practicality Φ18mm photocathode of image intensifier tube is plane electron source, GaAs photocathode sensitivity and other photoelectric performance lies on entire photocathode surface crystal quality, the photocathode module integrality reflected by the integral diffraction intensity plays crucial role of GaAs photocathode sensitivity. So integral sensitivity of Ф18 mm transmission-mode GaAs photocathode can be precisely predicted with X-ray integral diffraction intensity, some feasible ideas for further research of GaAs photocathode was obtained in this paper.

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An Image Intensifier - Television System for the Direct Recording of X-Ray Diffraction Patterns

IEEE Transactions on Nuclear Science ◽

10.1109/tns.1968.4324920 ◽

1968 ◽

Vol 15 (3) ◽

pp. 92-94 ◽

Cited By ~ 9

Author(s):

U. W. Arndt ◽

B. K. Ambrose

Keyword(s):

Image Intensifier ◽

X Ray Diffraction ◽

Television System ◽

X Ray ◽

Direct Recording ◽

Diffraction Patterns

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X-Ray Diffraction Orientation Studies Using Two-Dimensional Detectors

Advances in X-ray Analysis ◽

10.1154/s0376030800015883 ◽

1993 ◽

Vol 37 ◽

pp. 367-373 ◽

Cited By ~ 1

Author(s):

T.N. Blanton

Keyword(s):

Image Intensifier ◽

Ccd Camera ◽

Orientation Distribution ◽

Sensitive Area ◽

Two Dimensional ◽

X Ray Diffraction ◽

Storage Phosphor ◽

X Ray ◽

Film Image ◽

Position Sensitive

Two-dimensional detectors utilized in x-ray diffraction studies are described. Film, image intensifier/CCD camera, two-dimensional position-sensitive area, and photostimulable storage phosphor detectors are compared. The storage phosphor detector was found to be well suited for analysis of oriented semicrystalline polyester films. Quantitation of polymer orientation was determined using the Hermans orientation distribution function.

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Electro-Optical Systems for Dynamic Display of X-ray Diffraction Images

Advances in X-ray Analysis ◽

10.1154/s0376030800008466 ◽

1970 ◽

Vol 14 ◽

pp. 311-337 ◽

Cited By ~ 13

Author(s):

Robert E. Green

Keyword(s):

Image Intensifier ◽

Optical Systems ◽

List Type ◽

X Rays ◽

X Ray Diffraction ◽

Large Format ◽

Actual Performance ◽

X Ray ◽

Advantages And Disadvantages ◽

Fluorescent Screen

AbstractVarious electro-optical systems have been reported which permit intensification of X-ray diffraction patterns and thus a decrease in exposure time for recording and display of the X-ray images. Prior to 1966, all such electro-optical systems incorporated a large format X-ray image intensifier of the same type as conventionally used for medical and industrial fluoroscopy. In the past four years, a number of different systems have been reported which are superior to those developed prior to 1966. These systems may be grouped into two main categories, the large format variety for Laue diffraction applications, and the small format variety for topographic applications.The purpose of the present paper is to describe the particular characteristics of both the large format and small format systems and to discuss the advantages and disadvantages associated with each type. Based on actual performance characteristics it will be shown that:1.A multiple stage image intensifier system coupled to an external fluorescent screen is the most sensitive and only truly instantaneous system; it can be used with very weak X-ray intensities, the resolution is currently limited by the external fluorescent screen to 42μ the system is extremely versatile in that it can be used both for large format recording of Laue patterns as well as for small format recording of X-ray topographe; the system has a very long lifetime since nothing is altered by X-radiation.2.An X-ray sensitive vidicon is the least sensitive; it must be used with extremely high intensity X-rays or long exposure times; the resolution is the highest at approximately 15μ and is limited by either bandwidth of the television system, the thickness of the X-ray sensitive target or the size of the electron beam at the target; due to the small size of the X-ray sensitive target the system can only be used for small format recording of X-ray topographs; the lifetime of the system is short since X-radiation causes degradation of the target.

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