GB540640A - Improvements in or relating to electron multipliers - Google Patents

Abstract

540,640. Electron multipliers. BOSCH, F. J. G. VAN DEN., and VACUUM-SCIENCE PRODUCTS, Ltd. Feb. 23, 1940, Nos. 3474/40 and 3864/41. [Class 39 (i)] An electron multiplier of the type in which the secondary electrodes consist of apertured grids or plates comprises a series of such electrodes so spaced, and at such potentials, that the field between two succeeding electrodes is less than that between the following pair in the direction of motion of the electrons. Fig. 1 shows a construction in which the potentials of the electrodes 14 increase uniformly and the intervals between the electrodes decrease as shown. The apparatus also comprises a cathode 11, control grid 12, accelerating electrode 13, a final multiplying electrode 15 of plate form and a collecting electrode 16. The electrodes may be uniformly spaced and the difference of potential between them increases from one pair to the next. Between electrodes arranged as described may be placed intermediate electrodes at the same potential as the succeeding electrodes. The number of apertures in the secondary electrodes may increase as the collecting electrode is approached. The electrodes may be made of perforated plates constructed as described in Specification 516,621 and provided with auxiliary electrodes as described in Specification 531,541.