Abstract A multichannel electron multiplier has a plurality of multiplying stages. Each stage is formed from a flat plate of secondary electron emissive material slit into a plurality of fingers. Alternate fingers are twisted out of the plane of the plate at right angles thereto. The twisted fingers in successive stages are staggered to provide a plurality of zigzag electron multiplying channels. The source of electrons to be multiplied in a photo-electron emissive cathode and light is focused or collimated onto the photocathode at positions corresponding to the multiplying channels. In a second embodiment, the faceplate of a multiplier tube is a fibre optics plate and light is directed onto it by fibre optics light guides to positions corresponding to the multiplying channels. A focusing electrode is disposed between the photocathode and the first multiplying stage and serves to focus electrons onto the twisted fingers. The non-twisted fingers also help to focus electrons onto the twisted fingers in successive multiplying stages along the multiplying channels.
An electron multiplier having a hermetically sealed envelope, a plurality of secondary electron emissive multiplying electrodes in said envelope, said electrodes comprising a plurality of parallel conductive plates arranged one behind the other and slit to form fingers in the planes of said plates with alternate fingers being twisted out of the planes of the plates perpendicular thereto, the twisted fingers in successive plates being staggered to form separate zigzag electron multiplying channels.
Claim 2
Dependent Claim
73 words
An electron multiplier having a hermetically sealed envelope, a plurality of secondary electron emissive multiplying electrodes in said envelope, said electrodes comprising a plurality of parallel conductive plates arranged one behind the other and slit to form fingers in the planes of said plates with alternate fingers being twisted out of the planes of the plates perpendicular thereto, the twisted fingers in successive plates being staggered to form separate zigzag electron multiplying channels.
Claim 3
Dependent Claim
18 words
An electron multiplier according to claim 1 including a photocathode as a source of electrons to be multiplied.
Claim 4
Dependent Claim
28 words
An electron multiplier according to claim 1 including focussing means disposed between a source of electrons and a first of said plates to direct electrons into respective channels.
Claim 5
Dependent Claim
21 words
An electron multiplier according to claim 1 in which the envelope of the multiplier is provided with a fibre optics faceplate.
Claim 6
Dependent Claim
18 words
An electron multiplier according to claim 1, including collecting electrodes for collecting electrons having traversed said multiplying channels.