A semiconductor current source adapted for integrated circuit fabrication. A first transistor and a second diode-connected transistor have their base-emitter circuits coupled in parallel. A current-determining resistor is connected between the emitters of the transistors. The effective base-emitter junction area of the diode-connected transistor is greater than that of the first transistor. The collectors of the first and second transistors are coupled to feedback circuitry which tends to mainta...

A compact, short arc, high-pressure, xenon-filled light source provides high-intensity radiation with reliability and tolerance of severe environments. Specially shaped thoriated tungsten electrodes are fixed in opposed relation to nickel support blocks welded within a composite, uniform diameter, cylindrical envelope portion formed of a tube of alumina ceramic sealed to nickel-iron-cobalt alloy sleeves.

The invention relates to an ion source. This source comprises a gas ionization chamber, an electron source and means for oscillating the electrons in the chamber, so as to produce an ionization zone of the gas. The means for oscillating the electrons comprise two identical electron lenses, whose axes coincide with the oscillation direction, two spherical concave mirrors turned towards one another and positioned respectively on either side of the two lenses and whose centers respectively coincide...

A current source circuit is provided wherein the chip area consumption of a Miller multiplication capacitor is substantially reduced. A zero is created in addition to the pole created by the Miller multiplication capacitor. A first transistor is biased by a biasing means and has a base coupled to the emitter of a second transistor by a capacitor. The base of the second transistor is connected to the collector of the first transistor. A resistor is coupled between the emitter of the second transi...

A reservoir, extracting electrode and circular tungsten filament are maintained at high positive D.C. potential relative to a grounded electrode. Thermal electrons emanated from the filament irradiates and heats the bottom of the reservoir. As a result, powdered CsI held in the reservoir is melted and then forms a liquid CsI cone-shaped portion below the capillary formed at the reservoir bottom. Vaporized CsI molecules are created by further heating the cone-shaped portion, and are ionized by el...

A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energ...

A method is disclosed for partitioning a specification in a source code. In a first step, the specification is converted into a plurality of abstract syntax trees. In a second step, the plurality of abstract syntax trees is partitioned into at least a first set and a second set. The first set of abstract syntax trees is to be implemented by a first processor and the second set of abstract syntax trees is to be implemented by a second processor. The first and second set of abstracts syntax trees ...

A power source for providing a high frequency ac output voltage is provided with a rectifier, a smoothing circuit with an inductor and a smoothing capacitor, and an inverter having a switching device for switching the input dc voltage from the rectifier to provide a high frequency ac voltage output with reduced ripple. Also included in the smoothing circuit is a charge storage device by the operation of which the inductor receives electromagnetic energy from the current therein when the switchin...

A liquid pressure source, e.g. for use in soil mechanics laboratories, has a piston-cylinder unit driven by a stepper motor: a pressure transducer indicates the liquid pressure and a digital feedback control unit responds to generate stepping pulses to maintain a desired pressure. A step counter can be included to provide an accurate indication of volume change, and backlash compensation may be provided by arranging that the counter, following a direction change, ignores motor steps until a pres...

A seismic source operable in deep bore holes, and especially suitable for acoustic well logging and geophysical exploration, produces a controlled-spectrum seismic impulse. The source has a hammer which is hydraulically cocked through a hydraulic transformer into a hydraulic spring. Upon command, the hammer can be released, converting stored energy in the spring to kinetic energy of hammer motion. The hammer impacts on a liquid impulse shaping spring which couples impulse energy of controlled sp...