Abstract: Apparatus for forming an electron beam sheet includes a cathode member having a slot in a front surface thereof, a grid electrode and the anode of a thyratron. When it is desired to trigger the thyratron into conduction, a suitably large potential difference is applied between the cathode member and the grid, resulting in an electron beam sheet being produced extensive of a slot formed in the front surface of the cathode member. This produces ionisation and a main discharge current is established between the main anode and cathode of the thyratron.

Abstract: Laser apparatus includes a ceramic tube within which is contained a gas and a cylindrical cathode having a plurality of holes therethrough. An anode is located along the axis of the tube. During operation of the apparatus, a large potential difference is applied between the anode and cathode, causing a plurality of electron beams to be formed extensive of the holes. Vapor is emitted from the electron bombarded cylindrical rod and becomes excited, and laser action occurs.

Abstract: The present invention provides apparatus for forming electron beams, which may be advantageously employed in many applications, for example in display devices or thyratrons. A cathode member has a hole in its front surface. All the surfaces of the cathode member, except for the wall and base of the holes, are covered in an electrically insulating material such as glass. The cathode member and an anode member are contained within an envelope which also contains a gas filling. On application of a suitably high voltage between the cathode and anode members an electron beam is formed extensive in a direction away from the hole. The anode member may be located behind the front surface of the cathode member, and an electron beam still forms in front of the front surface.

Abstract: A segmented discharge tube device is provided, particularly for the discharge tube of a laser, in which a number of electrically isolated aluminium segments presenting a passage through which plasma may pass are located within an aluminium tube with heat conductive electrically insulating material in the form of anodization between the outer surfaces of the segments and the adjacent inner surfaces of the tube.