Design of a high-throughput grazing-incidence flat-field spectrometer.
The optical design of a high-throughput grazing-incidence flat-field spectrometer is presented. The spectral focal curve is almost a straight line because of the flat-field focusing properties of spherical variable-line-spaced gratings. The angular acceptance in the direction perpendicular to the plane of dispersion is maximized by means of a focusing spherical mirror mounted with its tangential plane coincident with the sagittal plane of the grating. Analytical calculations for the determination of the optimum mirror parameters are presented. A spectrometer for high-throughput experiments in the 800-60-eV region is designed with an extreme-ultraviolet-enhanced CCD detector: when the available flux is compared with that of a spectrometer with the same kinds of grating and detector but without a focusing mirror, the increase is as much as a factor 3.
Poletto
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L
Department of Electronics and Informatics, Istituto Nazionale per la Fisica della Materia, University of Padova, via Gradenigo 6yA, 35131 Padua, Italy. poletto@dei.unipd.it
Tondello
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