Abstract: A silica deposition tube is fused in a deuterium (D2) gas atmosphere and optionally baked in a deuterium (D2) gas atmosphere to substantially reduce the hydrogen content in the tube for decreased fiber attenuation. Alternatively, raw silica material is pre-treated in D2 gas followed by fusing of the raw silica tube in a D2 gas environment.

Abstract: A silica deposition tube is fused in a deuterium (D2) gas atmosphere and optionally baked in a deuterium (D2) gas atmosphere to substantially reduce the hydrogen content in the tube for decreased fiber attenuation. Alternatively, raw silica material is pre-treated in D2 gas followed by fusing of the raw silica tube in a D2 gas environment.

Abstract: A method for producing a silica glass body having a low bubble content includes melting silica sand in a chamber (62) of a rotating furnace housing (20) to form molten silica. Helium-containing gas is fed into the chamber, both during introduction of the sand and during the heating step. The helium diffuses more readily from the molten silica than other gases, resulting in lower bubble content. The furnace is heated by establishing a gas plasma arc (60) between spaced electrodes (64, 66) within the chamber.

Abstract: A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, at least a portion of the inner surface includes a barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof.

Abstract: A silica deposition tube is fused in a deuterium (D2) gas atmosphere and optionally baked in a deuterium (D2) gas atmosphere to substantially reduce the hydrogen content in the tube for decreased fiber attenuation. Alternatively, raw silica material is pre-treated in D2 gas followed by fusing of the raw silica tube in a D2 gas environment.

Abstract: A method for quartz crucible formation wherein an at least substantially enclosed chamber surrounds a crucible mold. The atmosphere in the chamber is controlled to include a desired gas or combination of gases at a positive pressure. The positive pressure is achieved because the total outflow of gas is less than the total inflow of gas. A heat source is initiated to melt a quartz material lining the mold once the desired atmosphere is achieved, and the quartz material is fused.

Abstract: A crucible for melting a silica for fusion of said silica into a desired shape. The crucible having a main body with inner and outer surfaces comprised of a refractory material. In addition, the inner surface adjacent at least a melting zone of the furnace includes a substantially gas-tight barrier layer comprised of a material selected from rhenium, osmium, iridium, and mixtures thereof.

Abstract: A low pressure discharge lamp, particularly a compact fluorescent lamp, achieves an overall reduction in height by orienting ends of the envelope radially inward for connection to the base. This advantageously positions the electrodes housed within the envelope away from the base. Moreover, this mounting arrangement provides resistance against pull out forces and elimination of a cement to secure the envelope to the base, as well as other improved heat transfer benefits.

Abstract: An interference filter or coating is provided in a predetermined pattern on a lamp envelope. The coating is comprised of alternating layers of high and low index of refraction materials applied to a vitreous outer surface of a lamp envelope. The coating may be geometrically symmetric or asymmetric, continuous or discontinuous with respect to the coating itself or the envelope to which it has been applied. The envelope can be masked prior to deposition of the coating so that removal of the mask leaves the filter in the desired pattern. The preferred process for forming the coating includes forming a boric oxide mask on a portion of the envelope, applying the coating over the mask and removing the coating from masked areas of the envelope by dissolving the mask in an aqueous solution.

Abstract: A lamp-to-light guide coupling arrangement includes an electrodeless high intensity discharge lamp comprising an arc tube with an ionizable fill, and an excitation circuit for electrically exciting the ionizable fill to induce therein a light-producing arc discharge. The coupling arrangement further includes a coupling device comprising a generally tubular, hollow body that has an inlet end for receiving light from the arc discharge and a larger, outlet end. The coupling device further comprises an interiorly directed reflector on a surface of the hollow body for reflecting visible light. Such coupling device is shaped so as to receive light at one solid angle over an area of the inlet end and to transmit light at a smaller solid angle but over a larger area of the outlet end. The coupling device is preferably formed from dielectric material. The reflector preferably comprises a refractory optical interference filter.

Abstract: An interference filter or coating is provided in a predetermined pattern on a lamp envelope. The coating is comprised of alternating layers of high and low index of refraction materials applied to a vitreous outer surface of a lamp envelope. The coating may be geometrically symmetric or asymmetric, continuous or discontinuous with respect to the coating itself or the envelope to which it has been applied. The envelope can be masked prior to deposition of the coating so that removal of the mask leaves the filter in the desired pattern. The preferred process for forming the coating includes forming a boric oxide mask on a portion of the envelope, applying the coating over the mask and removing the coating from masked areas of the envelope by dissolving the mask in an aqueous solution.

Abstract: A lamp assembly includes improved thermal management properties provided by a thermal shield received about the neck region of a reflector. This reduces the temperature in the seal region of the light source. Additionally, the thermal shield can be incorporated into a modular housing to provide a contained lamp assembly. The module includes cooling fins that effectively reduce the temperature of the module without adversely effecting the light output. Alternatively, the housing is operatively connected to an external, secondary heat sink.

Abstract: An incandescent lamp containing a coiled filament within a vitreous envelope wherein the filament is supported at at least one point along its coil length by a refractory metal support wire one end of which is welded to a coil and the other end secured to the envelope wall by a glass bead. The support prevents filament sag during lamp operation and is especially useful with double-ended high intensity tungsten-halogen lamps having an elliptically shaped filament chamber with an infrared reflecting and visible light transmitting optical interference coating on the chamber.

Abstract: Flush and pump flush processes yielding light sources for incandescent and metal vapor discharge lamps are disclosed. The flush and pump flush processes also yield lamps that are particularly suitable for deposition of a reflective coating on its outer surface. For such reflective coated light sources, the associated lamp leads are encased in glass and therefore are protected against any deleterious reactions that may otherwise result from the deposition of the reflective coating process. The light source yielded by the flush and pump flush processes of the present invention are advantageous in reducing the mounting arrangement of the lamps in which the light sources are housed.

Abstract: Flush and pump flush processes yielding light sources for incandescent and metal vapor discharge lamps are disclosed. The flush and pump flush processes also yield lamps that are particularly suitable for deposition of a reflective coating on its outer surface. For such reflective coated light sources, the associated lamp leads are encased in glass and therefore are protected against any deleterious reactions that may otherwise result from the deposition of the reflective coating process. The light sources yielded by the flush and pump flush processes of the present invention are advantageous in reducing the mounting arrangement of the lamps in which the light sources are housed.

Abstract: Flush and pump flush processes yielding light sources for incandescent and metal vapor discharge lamps are disclosed. The flush and pump flush processes also yield lamps that are particularly suitable for deposition of a reflective coating on its outer surface. For such reflective coated light sources, the associated lamp leads are encased in glass and therefore are protected against any deleterious reactions that may otherwise result from the deposition of the reflective coating process. The light sources yielded by the flush and pump flush processes of the present invention are advantageous in reducing the mounting arrangement of the lamps in which the light sources are housed.

Abstract: An electric incandescent lamp for selective radiant energy distribution is disclosed which employs a reflective film for improved efficiency of the lamp operation. Said lamp further employs a tungsten filament extending the length of its elongated lamp envelope with particular support means for said incandescent filament also being disclosed to precisely position the filament along the principal lamp axis. Various structural configurations for said particular support means are also disclosed so that such filament position is maintained regardless of the lamp spatial orientation.

Abstract: Flush and pump flush processes yielding light sources for incandescent and metal vapor discharge lamps are disclosed. The flush and pump flush processes also yield lamps that are particularly suitable for deposition of a reflective coating on its outer surface. For such reflective coated light sources, the associated lamp leads are encased in glass and therefore are protected against any deleterious reactions that may otherwise result from the deposition of the reflective coating process. The light sources yielded by the flush and pump flush processes of the present invention are advantageous in reducing the mounting arrangement of the lamps in which the light sources are housed.

Abstract: A capacitively ballasted low voltage lamp comprising a main capacitor connected electrically in series with the lamp, across an alternating current source, and one or more auxiliary capacitors that can be connected electrically across the main capacitor by switching means for one or more source waveform cycles. The minimum lamp current is established by the main capacitor, with additional lamp current flowing through one or more auxiliary capacitors during one or more source waveform cycles.

Abstract: A transducer to monitor a parameter and produce an acoustic signal from which the monitored parameter can be recovered. The transducer comprises a modified Galton whistle which emits a narrow band acoustic signal having a frequency dependent upon the parameter being monitored, such as the temperature of the cooling media of a nuclear reactor. Multiple locations within a reactor are monitored simultaneously by a remote acoustic receiver by providing a plurality of transducers each designed so that the acoustic signal it emits has a frequency distinct from the frequencies of signals emitted by the other transducers, whereby each signal can be unambiguously related to a particular transducer.