Microbeam Setup Research Articles

Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjörvarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials.In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a 4He2+ ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 μm2. The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information.The results of ERDA measurements on laterally diffused YHx (0<x<3) samples with a qualitatively known hydrogen concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described.

Improved capillary optics applied to microbeam x-ray fluorescence: Resolution and sensitivity

A new and improved type of x-ray capillary optics unit (ellipsoidal), is developed, tested, and characterized using a table-top x-ray microbeam setup. The beam profiles of the x-ray beams generated by the 7.5 μm ellipsoidal capillary were constructed from ‘‘knife-edge’’ scans across the beam. The detection limits for various elements were determined, and the spatial resolution, when the beam was used in scanning mode, was demonstrated.

On the proton microbeam of the Vrije universiteit, Amsterdam, and its applications

The proton microbeam set-up at Amsterdam has been in operation since January 1981. The main features of the equipment are presented as well as the results of beam profile measurements. The performance of the set-up will be illustrated by means of preliminary results of measurements on hair and arteries.