Soft X-ray Generation Research Articles

Enhancement of the ESDIAD method for imaging bond directionality in chemisorbed species

The ESDIAD method for imaging adsorbate bond directions by photographic observation of positive ion angular distributions during electron stimulated desorption suffers from inherent low contrast due to background effects. The use of a digital acquisition system designed to overcome this difficulty in ESDIAD measurement is presented. Measurements on a Ni(110) single crystal substrate show the presence of a significant background signal due to soft X-ray generation by electron impact. By subtraction of the background signal, a significant enhancement of positive ion signal-to-noise ratio is achieved in ESDIAD, converting the ESDIAD method into a high contrast, high resolution surface measurement technique. Quantitative studies of the soft X-ray background have shown it to be linearly dependent on electron current density and electron energy, with no change in angular shape. These properties permit an accurate background subtraction procedure to be employed to significant;y enhance the capability of the ESDIAD method.

Characteristics of plasmas imploded by ω, 2ω, 3ω and 4ω lasers

The wavelength scalings of soft X-ray and hot electron generation efficiencies were studied using 1·05, 0·53, 0·35 and 0·26 μm lasers. A coupling efficiency from absorbed laser energy to compressed fuel core of 4.5% was obtained by using the GEKKO XII green laser.

Nondispersive soft x-ray fluorescence spectrometer for quantitative analysis of the major elements in rocks and minerals

A Si(Li) detector and a multichannel analyzer system were combined with a multiple anode soft x-ray generator and a high vacuum sample handling system to provide an x-ray fluorescence unit for quantitative analyses of the elements from oxygen to iron. A relatively rapid, accurate, and reproducible sample preparation technique and a method for sample matrix absorption corrections are described. (auth)

Soft X-Rays from Crystal Faces

THESE experiments originated in an attempt to improve and extend those of Richardson and Chalklin on the generation of soft X-rays from surfaces of tungsten formed, by deposition in vacuo on carbon (Proc. Roy. Soc., A, 119, p. 71; 1928). In that investigation difficulties were met with owing to the deposition of impurities on the carbon target by the bombarding process necessary to secure the requisite high vacuum. To avoid this difficulty we made a target like two doors folded together on a hinge. We could bombard this target with the doors shut, and then open it out and so make the X-ray tests on the inner surface which had been heated but not exposed to the residual gases in the tube.