Abstract: Issues that are addressed in accordance with at least one presently preferred embodiment of the present invention, are: improvements upon the time it takes to physically swap degraders (done previously by hand); the safety involved in doing so, since the degraders become highly radioactive; possible improved energy resolution and beam stability if the accelerator can be left running continuously; and in-situ monitoring of beam current, beam position and stability. Particularly contemplated are methods and arrangements for changing degraders automatically, not manually, and in a safe manner.

Abstract: Direct and indirect electron bombardment provide a sufficiently high degree of temperature uniformity across the emitting surface of a large-area electron source for an electron beam projection system such that a broad beam having illumination uniformity within 1% can be achieved. A diode gun is used to obtain extraction field uniformity and maintain uniformity of illumination. Power requirements and power dissipation in beam periphery truncating apertures is reduced by roughening the surface of a monocrystalline cathode or depositing materials having a higher work function thereon.

Abstract: A charged particle beam apparatus having a cold trap positioned in proximity to components, such as a shaping aperture and a backscattered electrons detector, to which contaminants tend to migrate to adversely affect the functions of these components. As a coolant is passed through the cold trap, the contaminants condense on the cold trap and away from the shaping aperture and the backscattered electrons detector.