Abstract: A method of producing an ion beam in a tandem accelerator, the method includes the acts of insulating, in a cavity containing an insulating gas under pressure, a beam tube having first and second ends and a terminal situated between the first and second ends; seating, using a load lock valve, the insulating gas under pressure; generating an operating voltage using a first voltage source situated outside the cavity when the operating voltage is less than or equal to a threshold value; generating the operating voltage using a second voltage source situated inside the cavity when the operating voltage is greater than the threshold value; coupling the terminal to the first or second voltage sources; generating, using a particle source, an ion beam; and accelerating the ion beam in a first and second parts of the beam tube.

Abstract: An instrument for measurement of illumination intensity distribution of an Electron Beam Projection System (EBPS) comprises a reticle with a clear subfield, a pinhole plate comprising a block of a low atomic number material with a high aspect ratio pinhole therethrough, the pinhole plate being positioned at the image plane of the EBPS. Means is provided for detecting electrons passing through the pinhole, and means is provided for moving, scanning, the pinhole with respect to a fixed electron intensity distribution or scanning the electron intensity distribution with respect to pinhole when held in a fixed position.