Abstract: A method and apparatus for disinfecting material such as a fluid stream, (e.g., water) or various objects (e.g., packaging, fruits, vegetables) using a high temperature expanding plasma emission source (EPES lamp) to generate intense pulses of ultraviolet light primarily in the 200-400 nm range. The EPES lamp is preferably mounted axially in a pipe through which the fluid to be disinfected is flowed or perpendicular to the direction of a fluid flow or an object conveyor. Each pulse is terminated before the resulting plasma within the EPES lamp reaches the inside surface of the EPES lamp wall so that the EPES lamp operates in an expanding plasma emission source mode rather than in a wall stabilized mode. The EPES lamp is operated at a plasma temperature of at least about 15,000.degree. K. and an energy density (Q) of at least about 300.

Abstract: A flash lamp power supply system, comprising (a) a simmer power supply circuit, comprising (i) a DC simmer power supply, (ii) means for connecting a flash lamp in series with the DC power supply, and (iii) a capacitor connected in parallel to the power supply and to the flash lamp connecting means, wherein the impedance and capacitance of the simmer power supply are selected so as to provide dV/dT for the simmer power supply circuit equal to or greater than the rate at which the lamp impedance changes during a flash cycle; and (b) a pulse power supply circuit, comprising (i) a DC pulse source voltage supply, (ii) a thyristor, and (iii) means for connecting the lamp in series with the DC pulse source voltage supply and the thyristor, wherein the pulse power supply circuit further comprises a capacitor connected in parallel with the pulse source voltage supply.

Abstract: A reactor for the treatment of a fluid with a substantially uniform dosage of light from a light-type light source, which comprises:a reactor housing forming an internal space comprising a fluid entry region, a fluid exit region,a central photochemical treatment region comprising a housing, a means for circumferentially distributing fluid flow radially towards and perpendicular to a line-type light source, and a fluid exit region, wherein the central photochemical treatment of the housing is rotationally symmetrical about a central axis andone or more line-type light sources mounted in the treatment region substantially at the central axis of the housing, the axis of the lamps being oriented parallel to the rotational axis of the treatment region housing.Methods are also provided using the circumferential distribution of fluid flow radially toward and perpendicular to the line-type light source.

Abstract: An electrical excitation circuit is disclosed for a gas laser. The electrical excitation circuit includes a charging circuit connected in series with a pulse forming network between a power source and the laser load. The charging circuit includes a capacitor charged by the power source and a thyratron for transferring voltage to the pulse forming network. Alternatively, the charging circuit includes a capacitor charged upon the firing of a silicon controlled rectifier through a saturable step-up transformer which saturates for transferring voltage to the pulse forming network. The pulse forming network includes a saturable inductor switch positioned with respect to a capacitor so that when the voltage on the capacitor reaches a predetermined level, saturation of the saturable inductor switch releases electrical energy stored in the capacitor to the laser load.