Monk-Gillieson Monochromator

The theory developed by Seya, Namioka, and Sai has been numerically evaluated with the purpose of furnishing practical data for designing a Monk-Gillieson monochromator, in which coma-type aberration is eliminated at one specific wavelength of the designer's choice. The numerical results are conveniently arranged in the form of graphs and tables so as to facilitate estimation of the optimum instrumental constants and the performance to be expected. The calculations included here have been verified experimentally with a monochromator whose instrumental constants were so chosen, in accordance with the theory, as to eliminate the coma-type aberration at 3000 A. For practical interest, the performance of the above monochromator has also been compared with that of a Schroeder-type monochromator.