Abstract: A cathode configuration for emission of electrons has a reaction zone connected to an entrance opening for the supply of neutral particles. The opening communicates with the cathode configuration for the ionization of the neutral particles and an ion extraction system communicates with the reaction zone. Ions from the extraction system are sent to a detection system and a mechanism for the evacuation of the mass spectrometer arrangement. The cathode configuration includes a field emission cathode with an emitter surface, wherein at a short distance from this emitter surface, an extraction grid is disposed for the extraction of electrons, which grid substantially covers the emitter surface. The emitter surface encompasses herein at least partially a hollow volume such that a tubular structure is formed.

Abstract: A cassette Jacket for a 3.5" diskette comprising a front plate, rear plate, two fixed-side leaf springs, and a bottom plate. The front plate covers the read/write sector opening of the diskette. The rear plate covers the center opening and the read/write sector opening of the diskette. A retainer located on each leaf spring is received in an opening located in each side of the cassette to fix the Jacket on the cassette.