Abstract: An apparatus for simultaneously punching multiple holes in a ceramic substrate comprises a plurality of vertically movable and individually solenoid-operable punch drives disposed on a frame and selectively movable up and down relative to the frame. A horizontal arm extends from each of the punch drives and a punch extends from each of the extending arms and is movable vertically by the extending arms. Each of the punches is operable individually and operable simultaneously with selected others of the punches to punch one or more holes in a substrate at the same time. There may be provided at least four of the punches wherein the punches are disposed horizontally adjacent to one another in at least a 2.times.1 or a 2.times.2 grid with a spacing between adjacent punches of less than 8 mm.

Abstract: A beam of charged particles has its alignment and brightness alternately controlled in accordance with the current of the beam. The measurements of the current and any corrections for alignment or brightness are made when the beam is not applied to a target.

Abstract: circuit for controlling the electron discharge from a cathode, of an electron discharge device, which provides a control voltage signal, proportional to the cathode current, for comparison with a reference value to provide a correction bias to a grid interposed between the cathode and an anode.