The miniature cylindrical mirror analyzer: A new tool for surface analysis

The design and performance of a new miniature cylindrical mirror analyzer ( CMA) are presented. The CMA comprises outer and inner cylinders, an integra l on-axis electron gun, and a detector system consisting of ring aperture a nd channeltron, all mounted on a single 2.75 in. (70 mm o.d.) Conflat flang e. Entrance angle, sample-to-detector distance, and polar cone angle were c hosen, in consideration of second order focusing effects, which optimized a nalyzer transparency and resolution. Fringe field correction at the ends of the CMA is made by means of six rings precisely separated by sapphire insu lators. The electron gun is a one-lens electrostatic system equipped with a n x-y deflector for beam adjustment and scanning. A CeB6 low temperature ca thode operating at up to -3.0 keV delivers emission current up to 100 muA. The energy range of analyzed electrons can be varied between 0 eV and 3.0 k eV. The flange mounting also incorporates a high precision z-motion drive f or optimization of the working distance. The control electronics and softwa re permit operation of the instrument in pulse and analog phase sensitive d etection modes. Results obtained with this new mini CMA for a W(100) surfac e demonstrate an energy resolution (DeltaE/E) of 0.9%, which is comparable to larger 6 in. (152 mm) flange-mounted instruments. The very small size of the mini CMA permits its use in small or crowded ultrahigh vacuum chambers or where only 2.75 in. ports are available, thereby increasing flexibility in surface analysis. (C) 2001 American Institute of Physics.