A physically compact gas transport laser operable at high pulse rates (greater than 1 kHz) in a high vacuum (greater than 10.sup.-5 Torr) is achieved by flowing the active gas at high velocity (greater than 50 m/sec) between two discharge electrodes in a hermetically sealed housing containing squirrel cage type blowers, a heat exchanger and the laser electrodes. A pulse forming network and blower motors are mounted externally of the housing as is the optical resonator assembly. A central partition divides the housing interior into upper and lower gas flow channels. The blowers are located in the lower channel at the housing end downstream from the electrodes and are rotatable in a plane parallel to the plane of the partition. The heat exchanger is located at the opposite end of the housing and both cools and stabalizes the flow of the circulating gas. The housing is a unitary structure having openings for installation of the blowers, heat exchanger and optical windows, which openings are closed by removable metal-to-metal sealing flanges for permitting access to the housing interior without compromising high vacuum integrity of the system.
An improved drive coupling and bearing assembly for a recirculation fan in a long-life gas laser unit includes a plurality of frictionless gas bearings which allow journals supporting the recirculation fan to ride on a cushion of compressed laser gas. Mechanical power is transmitted from an external source to the recirculation fan through a magnetic coupling assembly, so that the walls of the sealed laser unit do not have to be breached. Additional structure is provided for spacing the driven magnet in the magnetic coupling assembly from the interior wall of the long-life laser unit.
A gas laser device comprises a discharge tube made of a dielectric material; a laser medium gas which is circulated at a high speed within the discharge tube in the axial direction of the discharge tube; an optical resonator composed of a total refelection mirror and a partial reflection mirror, both being disposed in mutual confrontation at both ends of the discharge tube; a plurality of electrodes oppositely provided on the outer periphery of the discharge tube; and a power source for applying an a.c. voltage to the oppositely provided electrodes to generate silent discharge.
A driving circuit for pulse current power supplies, particularly septum and kicker magnets for accelerators, with an inductance coil and a resonant circuit capacitor, has a thyratron, whose anode line is surrounded by a ring band core. A resistor and a second capacitor are connected in parallel to the thyratron. This arrangement permits operation of the thyratron at a higher forward voltage.
One illustrative embodiment of a voltage pulser circuit comprises a voltage source producing a first voltage, and a thyratron tube having an anode coupled to the output of the voltage source, a cathode connected to a reference potential and a grid responsive to a grid control voltage to electrically connect the anode to the cathode to thereby cause the first thyratron tube to switch the anode between the first voltage and the reference potential. A pulse-shaping circuit may be connected to the anode of the tube to effectuate desired rise and fall times of the voltage pulses produced by the voltage pulser circuit. Such a voltage pulser circuit is particularly suited for use in connection with the operation of pulsed spectrometer instruments, such as time-of-flight mass spectrometers and the like.
A discharge circuit for pulsed laser comprising a power source, main discharge electrodes for generating a laser beam, a main discharge capacitor charged with electrical charges for generating the main discharge between the main discharge electrodes, and a switching circuit for performing switching operations to charge the main discharge capacitor with electrical charges supplied from the power source in a prescribed repetition cycle, is provided, in parallel to the main discharge capacitors, with a circuit element for consuming or grounding the reverse current from the power source caused by overshoot generated directly after the main discharge, thereby attaining stable laser output without ill effects from overshoot voltage generated directly following discharge.
