GB1248825A

GB1248825A - Temperature-controlled orifice or slit for optical, ion-optical and electron-optical instruments

Info

Publication number: GB1248825A
Application number: GB40162/69A
Authority: GB
Inventors: Hermann Wollnik
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-08-14
Filing date: 1969-08-12
Publication date: 1971-10-06
Also published as: US3610734A; DE1797091B2; DE1797091A1; FR2022123A1

Abstract

1,248,825. Electron/ion beam tubes. H. WOLLNIK. 12 Aug., 1969 [14 Aug., 1968], No. 40162/69. Heading H1D. [Also in Division G2] A temperature-controlled orifice or slit for optical, ion-optical or electron-optical instruments comprises a plurality of plates having edges defining the orifice or slit mounted on a support having a temperature coefficient of expansion different from that of the plates. In a simple example the plates may be merely screwed to a supporting block having a hole for passage of a beam immediately beneath the centre of the slit. The block may be made of molybdenum and the plates of nickel, copper or aluminium. Both elements are heated from a common source and the combination of materials is chosen to give a required adjustment characteristic. The edges of the plates may overlap and be shaped so as to define a square or rectangular orifice. A number of plates may extend radially inwardly from a circular support and together define a square orifice at the centre after the manner of an adjustable iris. Fig. 6 shows plates 62, 63 defining a slit 65 above hole 69 in support 68. The plates are attached to the support by bimetallic flexural members 66, 67 which determine the width d of the slit. The movement of members 66, 67 may be limited by a pair of stops (118, 119, Fig. 11, not shown) which extend outwardly from the support 68. The slit plates themselves may be formed from a pair of flexural bimetallic laminae (Figs. 9, 10, not shown). In the arrangement of Fig. 3, a pair of plates 32, 33 defining a slit d are attached at A to a further pair 38, 39 of plates which are in turn attached at B to a third pair 36, 37 of plates, these being attached to an apertured support member 31 at C. The pairs of plates and the support are made of two materials which alternate throughout the structure, and which have relatively high and low expansion coefficients. The effect is to multiply the movement of the slit.