Abstract: To mount a discharge vessel (8) within an elongated bulb or envelope (2) le permitting thermal expansion of the discharge vessel (8) and yet maintaining the discharge vessel, free from vibration, within the tube in alignment with the longitudinal axis thereof, a flat leaf spring element (15, 15') (FIG. 2 ) is secured to a holder structure (5; 6a, 6b, 12) secured in the bulb and the respective electrode current connections (10a, 10b, 25a, 25b) to the discharge vessel, the flat leaf spring element being so located in the bulb that its major plane is oriented essentially perpendicularly to the longitudinal axis of the lamp.

Abstract: To retain an arc tube (6, 16) in precise position with respect to an opti system (R) within an outer envelope (2, 12), the arc tube is retained at both ends by spiral springs (23) which have a cylindrical portion fitted in a sleeve-like current supply (7, 17) to the arc tube and having a conically expanding portion (25), terminating in an end portion (26) which is welded to a central guide pin (27) fitted and movable within the cylindrical portion (24) of the spring. The guide pin (27) can form part of an internal current supply (FIG. 3: 19) or be secured to an internal current supply lead (FIGS. 1, 2: 9).

Abstract: An improved particle beam optical apparatus of the type having an evacuated housing with two sequential zones along the beam axis to be maintained at different low absolute pressures. A pressure stage detachably mounted in the housing between the zones is divided by an apertured partition into two portions communicating with the respective zones. From each portion a conduit leads through the body of the pressure stage for connection to respective vacuum pumps, the centerlines of the conduits lying in a common plane perpendicular to the beam axis. The body of the pressure stage preferably is adjustably mounted in a rigid support ring that is attached in vaccum-tight relation to the housing. The arrangement simplifies the vacuum connections, minimizes distortion of the housing and misalignment of the beam generating and control elements, and provides adjustment capability of the partition aperture.