Abstract:
Provided herein are approaches for improving ion beam extraction stability and ion beam current for an ion extraction system. In one approach, a source housing assembly may include a source housing surrounding an ion source including an arc chamber, the source housing having an extraction aperture plate mounted at a proximal end thereof. The source housing assembly further includes a vacuum liner disposed within an interior of the source housing to form a barrier around a set of vacuum pumping apertures. As configured, openings in the source housing assembly, other than an opening in the extraction aperture plate, are enclosed by the extraction aperture plate and the vacuum liner, thus ensuring appendix arcs or extraneous ions produced outside the arc chamber remain within the source housing. Just those ions produced within the arc chamber exit the source housing through the opening of the extraction aperture plate.
Abstract:
A closed drift ion source which includes a channel having an open end, a closed end, and an input port for an ionizable gas. A first magnetic pole is disposed on the open end of the channel and extends therefrom in a first direction. A second magnetic pole disposed on the open end of the channel and extends therefrom in a second direction, where the first direction is opposite to the second direction. The distal ends of the first magnetic pole and the second magnetic pole define a gap comprising the opening in the first end. An anode is disposed within the channel. A primary magnetic field line is disposed between the first magnetic pole and the second magnetic pole, where that primary magnetic field line has a mirror field greater than 2.
Abstract:
An electron beam controlled switch employing a radial geometry and a Wire-Ion Plasma-Electron gun (WIP E-gun) as an electron source is disclosed. The switch comprises an inner cylinder that serves as the WIP E-gun cathode, a cylindrical grid that serves as the WIP E-gun anode, an array of fine wire anodes disposed in the WIP E-gun ionization chamber, a foil support cylinder to support the foil windows which also serve as the switch anode, and an outer cylinder which also serves as the switch cathode. The WIP E-gun and ionization chamber is gas filled at low pressure, while the switch cavity is filled with a high pressure gas. A voltage pulse is applied to the wire anodes to ionize the gas in the ionization chamber. The ions are extracted through the chamber grid and accelerated through a high voltage to bombard the E-gun cathode. The electrons emitted from the ion bombardment are accelerated outwardly through the high voltage, penetrate through the foil windows and into the pressurized gas in the switch cavity. The high energy electrons ionize the gas between the switch anode and cathode, thereby turning "ON" the switch. In the absence of the electron beam, the switch gas deionizes and switch conduction is quickly extinguished.
Abstract:
An improved liquid-film electron stripper particularly for high intensity heavy ion beams which produces constant regenerated, stable, free-standing liquid films having an adjustable thickness between 0.3 to 0.05 microns. The improved electron stripper is basically composed of at least one high speed, rotating disc with a very sharp, precision-like, ground edge on one said of the disc's periphery and with a highly polished, flat, radial surface adjacent the sharp edge. A fine stream of liquid, such as oil, impinges at a 90.degree. angle adjacent the disc's sharp outer edge. Film terminators, located at a selected distance from the disc perimeter are positioned approximately perpendicular to the film. The terminators support, shape, and stretch the film and are arranged to assist in the prevention of liquid droplet formation by directing the collected film to a reservoir below without breaking or interfering with the film. One embodiment utilizes two rotating discs and associated terminators, with the discs rotating so as to form films in opposite directions, and with the second disc being located down beam-line relative to the first disc.
Abstract:
The field-emission-type ion source according to the present invention comprises an emitter tip, a heater, a reservoir which stores material to be ionized, an extracting electrode situated at the front end of the emitter tip, and a coating-layer which is refractory and anti-reactive with the material to be ionized and which is coated on at least the heater of the emitter tip and heater, in order to prevent their reactions with the material to be ionized.
Abstract:
Apparatus for producing sample ions comprising means of producing metastable species by corona discharges in the carrier gas, a needle-shaped emitter whose pointed end is inserted into the stream of carrier gas which transports said metastable species, means for applying a high potential to said needle emitter, wherein sample is arranged adjacent to or deposited on the pointed end of said emitter. Its value is further enhanced when it is combined with a mass spectrometer.
Abstract:
A dispenser for supplying metal vapor to an ion source. The metal is provided in a capsule which may be broken to release the metal by turning a knob which causes a capsule housing to move to the right, thus causing the capsule to break against a piston member. The piston member communicates with a conduit which in turn communicates with the associated ion source, partly shown in the drawing. A heating mantle is provided to vaporize the metal in the housing so that it can pass from the dispenser through a conduit, to the ion source.
Abstract:
An electron and ion accelerator includes plural spaced electrodes which are apertured to define a gas discharge path and supported at their peripheries by insulative means. A gas supply provides low pressure gas capable of producing electrons and ions in the gas discharge path. A voltage applied between the at least two electrodes establishes an electrical potential between them such that a spark-like gas discharge occurs along the gas discharge path. The current density obtainable in the low pressure gas is substantially higher than the density of an electron or ion flow in a vacuum.
Abstract:
An improved means for generating a negative charge effect in the environment, in which oppositely charged electrically conductive plates are coated with secondary emissive material and are enclosed in a sealed container such as glass that is preferably filled with an inert gas such as argon.
Abstract:
A beam-plasma type ion source comprises a first section for generating an electron beam, a cylindrical second section for ionizing a gas by virtue of electron bombardment caused by the electron beam generated from the first section, a microwave energy transmission circuit disposed in the second section and connected to receive microwave energy in order to cause plasma ionization, and a third section for collecting the electron beam. The gas introduced into the third section is ionized at the second section and extracted by and accelerated in the first section in the opposite direction to the electron beam way. The first section functions to converge an ion beam to generate a well-focused ion beam toward a desired target by means of ions trapped into a negative-potential well due to the electron beam.