Evaluation of Charge-Injection Devices for Use in Laue Diffraction Imaging

Hanley, Quentin S.; True, John; Denton, M. Bonner

doi:10.1107/s0909049595007849

Cited by 3 publications

(3 citation statements)

References 9 publications

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“…While such a detector would be desirable, it is not a requirement. Detectors that might be used for this purpose are siliconintensified targets (SITs) (Arndt, 1990;Li, Phillips, Stanton & Kalata, 1992), charge-coupled devices (CCDs) (Phillips, Li, Stanton, Xie & O'Mara, 1993;Allinson, 1989), charge-injection devices (CIDs) (Hanley, True & Denton, 1995), image plates (Miyahara, Takahashi, Amemiya, Kamiya & Satow, 1986), multiwire detectors, and even photographic film. It should also be noted that single-channel detectors such as avalanched photodiodes, GM counters, scintillation counters and ion chambers could also be used.…”

Section: Instrumental Considerations -Detectorsmentioning

confidence: 99%

“…The difference between the literature value for the Mo Kot radiation and the mean value of energy measured with each foil is reported as systematic error. A series of Laue diffraction images of tetraphenylphosphonium tetrachlorooxomolybdenum(V) were taken using an indirect charge-injection-device camera system previously described (Hanley, True & Denton, 1995). Exposures were taken with and without the foils attenuating the incident beam.…”

Section: Figurementioning

confidence: 99%

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A Foil-Mask Spectrometer for Laue Pattern Imaging: Simultaneous Position, Intensity and Energy

Hanley

Dunphy

Denton³

1996

J Synchrotron Radiat

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An X-ray spectrometer for simultaneous position, intensity and energy determinations suitable for Laue diffraction applications is described. The foil-mask spectrometer consists of a series of metal foils of varying composition and thickness which are used to modulate the energy distribution of an incident X-ray source. Three modes of operation are described: a high-resolution spectrometer for measurement of nearly monochromatic X-rays, an intensity discriminator for partitioning the intensity from a small number of spatially overlapped monochromatic X-ray sources, and a lowresolution spectrometer for polychromatic X-rays with broad spectral features. The first mode of operation is designed to allow the energy of monochromatic Laue reflections to be measured with a resolution suitable for determination of unit-cell parameters. The second mode of operation is designed to allow the intensity of each component in a spatial region containing overlapping orders or spatially overlapped reflections to be discriminated for use in refinements or space-group assignment. The third mode of operation is described for completeness. The theory behind each mode of operation is described. The energy resolution of the spectrometer improves with the square root of the intensity of the incident beam. It also increases linearly with the change in energy with respect to transmission efficiency of a particular foil. In theory, the resolution of the spectrometer can readily exceed 50 eV over a wide range of energies depending on the foils used and the incident X-ray photon flux. Determinations of the energies of Mo Kc~ and Cu Kc~ radiation using a firstgeneration ten-foil spectrometer gave values of 17.5+0.1 and 8.08+0.05keV, respectively. Treatment of random error shows good correspondence with a Poisson model. The use of this spectrometer is demonstrated using a sample of tetraphenylphosphonium tetrachlorooxomolybdenum(V). Comparison of predicted and observed energies shows good agreement over a wide range of energies. The ratio of predicted to measured energy for the first 50 measurements was 0.9918 + 0.0344. Up to three components of a position having harmonic overlap were separated. This work demonstrates the feasibility of using Laue diffraction to completely determine the crystal structure of a molecule without recourse to monochromatic methods.

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Section: Instrumental Considerations -Detectorsmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

A Foil-Mask Spectrometer for Laue Pattern Imaging: Simultaneous Position, Intensity and Energy

Hanley

Dunphy

Denton³

1996

J Synchrotron Radiat

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“…Data were collected using an indirect CID camera system (Hanley, True & Denton, 1995), an Enraf-Nonius FR571 X-ray source equipped with a Cu rotating anode, and a CAD-4 goniometer. Images were processed using the image reduction and analysis facility (IRAF).…”

Section: Data Collectionmentioning

confidence: 99%

Application of Energy-Resolved Measurements to Laue Diffraction: Determination of Unit-Cell Parameters, Deconvolution of Harmonics and Assignment of Systematic Absences

Hanley¹,

Campbell²,

Denton³

1997

J Synchrotron Radiat

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The use of energy-resolved area detection of Laue diffraction patterns for the determination of unitcell parameters and systematic absences is demonstrated. Seven different crystals having previously known unit cells were re-examined using Laue diffraction methods. These crystals included four different crystal systems including cubic, orthorhombic, tetragonal and monoclinic cells. The crystals had cell sizes ranging from 179.4 to 4588.3 A~. Comparison of known and re-determined cells showed good agreement (ratio of known to measured cells = 0.987 _+ 0.18). A single procedure was suitable for all unit-cell determinations. The accuracy of the method is presently limited by the quality of the available energy measurements. Some of the crystals represent space groups containing systematic absences normally obscured by harmonic overlap when using the Laue method. These include absences due to 21 screw axes (h, k or 1 = 2n + 1) and cell centering (h + k = 2n + 1). All systematic absences were identified using a combination of multiple linear regression with either stepwise elimination or stepwise inclusion and an F test for assignment of systematic absence. The methods are discussed in detail and simulations are used to evaluate critical tolerances for future systems.

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Charge-coupled device area x-ray detectors

Grüner

Täte

Eikenberry

2002

Review of Scientific Instruments

244

146

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Charge-coupled device (CCD) area x-ray detector technology is reviewed. CCD detectors consist of a serial chain of signal components, such as phosphors, fiber optics or lenses, image intensifiers and the CCD which serve to convert the x-ray energy to light or electron-hole pairs and to record the spatially resolved image. The various combinations of components that have been used to make CCD detectors are described and the properties of each of the critical components are discussed. Calibration and correction procedures required for accurate data collection are described. The review closes with a brief description of future directions for solid-state area x-ray detectors.

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Evaluation of Charge-Injection Devices for Use in Laue Diffraction Imaging

Cited by 3 publications

References 9 publications

A Foil-Mask Spectrometer for Laue Pattern Imaging: Simultaneous Position, Intensity and Energy

A Foil-Mask Spectrometer for Laue Pattern Imaging: Simultaneous Position, Intensity and Energy

Application of Energy-Resolved Measurements to Laue Diffraction: Determination of Unit-Cell Parameters, Deconvolution of Harmonics and Assignment of Systematic Absences

Charge-coupled device area x-ray detectors

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