Journal of X-Ray Science and Technology - Volume 1, issue 2

Authors: van Brug, H. | van Dorssen, G. E. | van der Wiel, M. J.

Article Type: Research Article

Abstract: Soft x-ray emission spectra (250–875 eV) are presented for plasmas, produced by picosecond and nanosecond frequency-doubled Nd:YAG-glass laser pulses incident on 14 different target materials. The emitted spectra have been corrected for various apparatus functions which enables a direct comparison between plasmas produced by pico- and nanosecond laser pulses. The relative integrated emission intensity as a function of Z number, obtained from the corrected spectra, shows an oscillatory behavior, with distinct maxima for those elements exhibiting a dominant line emission in our photon energy window. We found for our two pulse lengths an approximately equal conversion efficiency from laser light …into x-ray photons. General suggestions are given as to what target material should be used for different applications using the laser plasma as x-ray source in the energy range Studied. Show more

DOI: 10.3233/XST-1989-1201

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 121-133, 1989

Authors: Schwarzenberger, D. R. | Chetwynd, D. G. | Bowen, D. K.

Article Type: Research Article

Abstract: A phase-step procedure is used with an x-ray interferometer to allow the use of standard phase-plot methods of fringe analysis. When used to measure displacement, this method allows more precise and reliable interpolation of fringe spacings than methods previously reported and is more tolerant of experimental uncertainties. Using the silicon (111) lattice planes as diffracting elements (period 0.3135625 nm), displacement measurements with a standard deviation of 0.003 nm can be routinely achieved. The experimental and data analysis methods required to achieve this resolution are reported.

DOI: 10.3233/XST-1989-1202

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 134-142, 1989

Authors: Allinson, N. M. | Brammer, R. | Helliwell, J. R. | Harrop, S. | Magorrian, B. G. | Wan, T.

Article Type: Research Article

Abstract: A direct charge coupled device (CCD) detector has been used to record Laue diffraction data from a protein crystal illuminated with a synchrotron radiation beam of continuous wavelengths 0.2 Å < λ < 2.5 Å. The exposure time used to record the data was 40–80 ms. The point spread factor of the detector was negligible. The sensitivity of CCD detectors at high photon energies is discussed in relation to other electronic area detector schemes. The lack of fine energy resolution of this or any other electronic area detector is not considered a limiting factor because of the high proportion of …spots of single wavelength arising from single reciprocal lattice points. A time-resolved study of radiation damage to a crystal of concanavalin A was performed. Show more

DOI: 10.3233/XST-1989-1203

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 143-153, 1989

Authors: Tsacoyeanes, James | Feng, Tom

Article Type: Research Article

Abstract: In this paper, we show the usefulness of diamond films for improving the survivability of thin film metal mirrors against intense x rays. Essentially, the low-Z, high thermal conductivity diamond film acts as an efficient heat sink, thus reducing the temperature in the metal film. A comparison is made between a diamond film and a beryllium film interposed between an aluminum/fused silica mirror. It is shown that at relatively low x-ray fluence, beryllium is somewhat more effective in reducing the aluminum temperature, whereas at high fluence, diamond is more effective.

DOI: 10.3233/XST-1989-1204

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 154-161, 1989

Authors: Goodman, D. A. | Eason, R.W. | Shiwai, B. | Allinson, N. | Magorrian, B. | Grande, M. | Ridgley, A.

Article Type: Research Article

Abstract: A crystal spectrometer with a photodiode array (PDA) detector was tested for a range of x-ray energies between 1 and 2 keV. A laser-produced plasma has been used as an x-ray source and was generated by the high-power (Vulcan) glass laser system at the SERC Rutherford Appleton Laboratory, UK. The performance of the array was directly compared with the response of Kodak DEF x-ray film. In order to compare quantitatively the performances of the PDA and the film, detective quantum efficiency (DQE) considerations are presented for both devices. It is demonstrated that the PDA has a useful dynamic range which …is approximately seven times greater than that of film, a peak DQE of approximately six times that of film, and a greatly superior low-signal performance. The operational characteristics of the PDA are discussed. Show more

DOI: 10.3233/XST-1989-1205

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 162-170, 1989

Authors: Tjahjadi, T. | Bowen, D. K.

Article Type: Research Article

Abstract: This paper examines the effectiveness in displaying monochrome images as color images and presents a pseudo-color enhancement technique for enhancing features in x-ray microtomographs of biological and inorganic materials. The technique utilizes the knowledge that the gray levels (intensities) in the image represent the linear absorption coefficients of the elements in the material and assigns pixels with similar gray levels and hence similar absorption coefficients to a color. Since each color in the pseudo-color enhanced image represents a range of gray levels and this corresponds to an element or phase in the material, its microstructure can easily be determined. This …paper also discusses the problems associated with the selection of colors and presents a scheme which uses the CIE 1976 L* u* v* uniform color space to select 256 colors for replacing the 256 gray shades used to represent the monochrome image. Show more

DOI: 10.3233/XST-1989-1206

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 171-189, 1989

Authors: Shealy, David L. | Gabardi, David R. | Hoover, Richard B. | Walker Jr., Arthur B. C. | Lindblom, Joakim F. | Barbee Jr., Troy W.

Article Type: Research Article

Abstract: Normal incidence multilayer Cassegrain x-ray telescopes were flown on the Stanford/MSFC Rocket X-Ray Spectroheliograph. These instruments produced high spatial resolution images of the Sun and conclusively demonstrated that doubly reflecting multilayer x-ray optical systems are feasible. The images indicated that aplanatic imaging soft x-ray /EUV microscopes should be achievable using multilayer optics technology. We have designed a doubly reflecting normal incidence multilayer imaging x-ray microscope based on the Schwarzschild configuration. The Schwarzschild microscope utilizes two spherical mirrors with concentric radii of curvature which are chosen such that the third-order spherical aberration and coma are minimized. We discuss the design of …the microscope and the results of the optical system ray trace analysis which indicates that diffraction-limited performance with 600 Å spatial resolution should be obtainable over a 1 mm field of view at a wavelength of 100 Å. Fabrication of several imaging soft x-ray microscopes based upon these designs, for use in conjunction with x-ray telescopes and laser fusion research, is now in progress. High resolution aplanatic imaging x-ray microscopes using normal incidence multilayer x-ray mirrors should have many important applications in advanced x-ray astronomical instrumentation, x-ray lithography, biological, biomedical, metallurgical, and laser fusion research. Show more

DOI: 10.3233/XST-1989-1207

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 190-206, 1989

Authors: Ford, T. W. | Stead, A. D. | Hills, C. P. | Rosser, R. J. | Rizvi, N.

Article Type: Research Article

Abstract: Soft x-ray contact images have been obtained of diatom skeletons using laser-generated plasmas of low energy (2 J IR). These images have a resolution of less than 60 nm, which is superior to that reported previously for biological specimens, using this technique.

DOI: 10.3233/XST-1989-1208

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 207-210, 1989

Authors: Michette, A. G.

Article Type: Other

DOI: 10.3233/XST-1989-1209

Citation: Journal of X-Ray Science and Technology, vol. 1, no. 2, pp. 211-211, 1989