Abstract:
A method for making a metal fluoride trap comprising: assembling a precipitation tube assembly including a plurality of precipitation tubes supported between a first tube end support and a second tube end support; assembling a precipitation tube, flowsheet and filter media assembly including: wrapping a flowsheet around at least one full circumference of the plurality of precipitation tubes, wherein the flowsheet has a width less than a length of the plurality of precipitation tubes between the first tube end support and the second tube end support; and wrapping a filter media around the wrapped flowsheet, wherein the filter media and the flowsheet are wrapped so as to have a diameter less than an inner diameter of an outer casing of the metal fluoride trap; inserting the precipitation tube, flowsheet and filter media assembly into the outer casing of the metal fluoride trap; allowing the flowsheet to expand; and pressing the filter media between the flowsheet and an inner surface of the outer casing of the metal fluoride trap. A method of filtering gas in metal fluoride trap is also disclosed. A metal fluoride trap apparatus is also disclosed.
Abstract:
A method and apparatus if disclosed which may comprise a high power high repetition rate gas discharge laser UV light source which may comprise: a gas discharge chamber comprising an interior wall comprising a vertical wall and an adjacent bottom wall; a gas circulation fan creating a gas flow path adjacent the interior vertical wall and the adjacent bottom wall; an in-chamber dust trap positioned a region of low gas flow, which may be along an interior wall and may comprise at least one meshed screen, e.g., a plurality of meshed screens, which may comprise at least two different gauge meshed screens. The dust trap may extend along the bottom interior wall of the chamber and/or a vertical portion of the interior wall. The dust trap may comprise a first meshed screen having a first gauge; a second meshed screen having a second gauge smaller than the first gauge; and the second meshed screen intermediate the first meshed screen and the interior wall. The chamber may comprise a plurality of dust collecting recesses in at least one of the vertical interior wall and the bottom wall of the chamber which may be selected from a group comprising a one-part recess and a multi-part recess, which may comprise two sections angled with respect to each other. The dust trap may comprise a pressure trap positioned between a portion of a main insulator and an interior wall of the chamber. The chamber may comprise a gas circulating fan comprising a cross-flow fan with a fan cutoff that may comprise a vortex control pocket. The chamber may comprise a preionization mechanism comprising a preionization tub containing a ground rod within an elongated opening in the preionization tube that may comprise a compliant member, an automatic preionization shut-off mechanism, a preionization onset control mechanism and/or a focusing element. The chamber may comprise an elongated baffle plate that may comprise a plurality of pyramidal structures including varying numbers of generally pyramidal elements and oriented in groups of varying numbers of generally pyramidal elements and oriented along and transverse to the longitudinal axis. Acoustic resonances within the chamber may also be reduced by introducing an artificial jitter into the timing of the laser discharges varying the inter-pulse period randomly or in a repeating pattern from pulse to pulse within a burst.
Abstract:
A cross-flow fan impeller for circulating gas in a transversely excited, pulsed, gas discharge laser is disclosed and may comprise a plurality of hubs, the hubs spaced apart along the impeller's rotation axis and establishing at least two impeller segments wherein a first segment has an output flow within 80-120% of a second segment and the first and second segment having differing blade pass frequencies. In some embodiments of this aspect, the first segment may have n number of blades the second segment m number of blades, and m≢n. In one embodiment, the impeller may be configured with n=29 and m=23 and in another embodiment, the impeller may be configured with n=23 and m=19. The impeller may be configured wherein n and m are prime numbers.
Abstract:
A laser device is capable reducing fluctuation of the beam width of the output laser beam due to abrasion of its discharge electrodes. A part of the contour shape of a section perpendicular to the longitudinal axis of the chamber of the laser device in at least one of the electrodes, which part confronts the other one of the electrodes, has a shape of a circular arc having a predetermined radius. The width of at least one of the two electrode may be substantially equal to the width of electric discharge taken place between the electrodes. Further, a conductor member may be disposed on each side of the electrode along its longitudinal axis to reduce electric field strength therearound.
Abstract:
A apparatus and method are disclosed which may comprise a fluorine gas discharge laser system and electrode support system which may comprise a first electrode electrically connected to a source of high voltage; a first insulating mechanism insulating the first electrode from ground; a second electrode electrically insulated from the source of high voltage and together with the first electrode forming an elongated discharge region between portions of the first and second electrodes respectively extending along a longitudinal axis of each of the first and second electrodes, defining electrode discharge receiving region end portions; a plurality of current return tines electrically connected to the second electrode and to ground, the tines distributed along the longitudinal extent of the elongated discharge region; a second insulating mechanism electrically isolating the second electrode from ground except through the plurality of current return tines.
Abstract:
A gas laser outputs a prescribed high power from the start of laser oscillation immediately after the laser gas is changed. The laser, in which used laser gas in a laser chamber (1) is replaced with a fresh laser gas, is provided with: a gas leaving means, which leaves a prescribed amount of used gas for mixing with the fresh laser gas during laser gas replacement, or an impurity gas adding means which provides a prescribed amount of impurity gas for mixing with the fresh laser gas; and a controller (11). It is preferable that the concentration of the used gas after a replacement is within a range of 1.5-60%. The gas leaving means can be a gas discharge control mechanism (10), which controls the amount of used gas exhausted so that a prescribed amount of used gas can be left for mixing with the fresh gas, or a laser gas container (21), which can provide a prescribed amount of stored used gas for mixing with the fresh gas. The impurity gas adding means can be a laser gas cylinder containing a prescribed concentration of impurity gas or an impurity gas container (44).
Abstract:
A cross-flow fan impeller for circulating gas in a transversely excited, pulsed, gas discharge laser is disclosed and may comprise a plurality of hubs, the hubs spaced apart along the impeller's rotation axis and establishing at least two impeller segments wherein a first segment has an output flow within 80-120% of a second segment and the first and second segment having differing blade pass frequencies. In some embodiments of this aspect, the first segment may have n number of blades the second segment m number of blades, and m≠n. In one embodiment, the impeller may be configured with n=29 and m=23 and in another embodiment, the impeller may be configured with n=23 and m=19. The impeller may be configured wherein n and m are prime numbers.
Abstract:
An apparatus used for elimination of the influence of spiking in an excimer laser device. The values of predetermined parameters which contribute to the spiking such as oscillation suspension time in a successive pulse oscillation are obtained. Discharge voltage for each of the successive laser beam pulses is changed on the basis of the obtained parameter values such that subsequent successive laser beam pulses have the same energy. The discharge voltage is stored according to time elapsed after the start of the successive pulse oscillation, and discharge voltage is controlled such that stored discharge voltage corresponds to the measured elapsed time. During the time when a stepper is not performing processing using the laser beam, the laser beam pulse is oscillated under predetermined conditions and the energy of the resulting pulses is detected. The stored discharge voltage is corrected on the basis of the detected magnitude of the pulse energy, a desired magnitude of the pulse energy and the predetermined conditions. The discharge voltage is controlled such that the corrected discharge voltage is obtained during the time when the stepper performs the processing using the laser beam.
Abstract:
According to present invention, the central wavelength of the central wave of the output laser beam, and the sideband wave power or central wave power of the output laser beam are detected, and the wavelength selective characteristics of wavelength selective elements disposed between a laser chamber and a rear mirror are controlled such that the detected central wavelength falls within a desired allowable range and that the detected power becomes minimum or maximum.
Abstract:
A method for making a metal fluoride trap including: assembling a precipitation tube assembly including a plurality of precipitation tubes supported between a first tube end support and a second tube end support; assembling a precipitation tube, flowsheet and filter media assembly including: wrapping a flowsheet around at least one full circumference of the plurality of precipitation tubes, wherein the flowsheet has a width less than a length of the plurality of precipitation tubes between the first tube end support and the second tube end support; and wrapping a filter media around the wrapped flowsheet, wherein the filter media and the flowsheet are wrapped so as to have a diameter less than an inner diameter of an outer casing of the metal fluoride trap; inserting the precipitation tube, flowsheet and filter media assembly into the outer casing of the metal fluoride trap; allowing the flowsheet to expand; and pressing the filter media between the flowsheet and an inner surface of the outer casing of the metal fluoride trap. A method of filtering gas in a metal fluoride trap is also disclosed. A metal fluoride trap apparatus is also disclosed.