Abstract: Methods for producing an optical fiber by elongating a silica glass blank or a coaxial group of silica glass components, on the basis of which a fiber is obtained that comprises a core zone, an inner jacket zone enclosing the core zone and a ring zone surrounding the inner jacket zone, are known.

Abstract: One aspect is a process to producing a synthetic quartz glass, including an annealing treatment that includes: putting a synthetic quartz glass as a parent material into a heat treatment furnace; elevating a temperature in the heat treatment furnace to a prescribed keeping temperature that is equal to or higher than the annealing point; keeping the keeping temperature; annealing the synthetic quartz glass; and taking the synthetic quartz glass out of the heat treatment furnace. The process includes determining an annealing rate v [° C./h] of the annealing step based on a value of S/V [mm2/mm3], wherein S [mm2] is the surface area of the synthetic quartz glass as a parent material and V [mm3] is the volume thereof and a target birefringence Re [nm/cm] for the synthetic quartz glass after the annealing, and the annealing step is performed at the determined annealing rate v.

Abstract: A low cost method for producing a mechanically and thermally stable composite body containing a first layer of a material with a high silicic acid content and an additional component connected to a second layer of a material with a high silicic acid content and an additional component in a second concentration differing from the first concentration is provided. The method involves (a) preparing a first slurry layer having a free surface using a first shirt mass containing SiO2 particles and an additional component dispersed in a first dispersing agent, (b) providing a second slurry mass containing SiO2 particles and an additional component in a second concentration dispersed in a second dispersing agent, (c) forming a composite-body intermediate product by applying the second slurry mass to the free surface of the first slurry layer, and (d) heating the composite-body intermediate product while forming the composite body.

Abstract: A method for producing a component with portions of a rare earth metal-doped quartz glass, an intermediate product containing voids and consisting of a SiO2 raw material doped with rare earth metal is introduced into a sinter mold the interior of which is bordered by a carbonaceous mold wall, and is melted therein into the component by gas pressure sintering at a maximum temperature above 1500° C. A shield is arranged between the mold wall and the intermediate product. In order to indicate a modified gas pressure sintering method that ensures the production of rare earth metal-doped quartz glass with reproducible properties, a bulk material of amorphous SiO2 particles with a layer thickness of at least 2 mm is used as the shield, the softening temperature thereof being at least 20° C.

Abstract: In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm3, and at a temperature of 1000° C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 ?m.

Abstract: A method for producing synthetic quartz glass by fusion of SiO2 granulate involves synthesizing amorphous SiO2 primary particles, granulating the amorphous SiO2 primary particles to form an open-pore SiO2 granulate, sintering the open-pore SiO2 granulate by heating in a sintering atmosphere at a sintering temperature and for a sintering period to form a densified SiO2 granulate, and melting the densified SiO2 granulate at a melting temperature to form the synthetic quartz glass. To provide an inexpensive production of low-bubble transparent components of quartz glass despite the use of still open-pore SiO2 granulate, the sintering atmosphere, sintering temperature and sintering duration are adjusted such that the densified SiO2 granulate still comprises open pores but manifests a material-specific infrared transmission T1700 at a wavelength of 1700 nm. This transmission is in the range of 50-95% of the infrared transmission T1700 of quartz glass granules of the same material.

Abstract: Common solar radiation receivers are equipped with a chamber for transmission of an operating gas which is directed along to an absorber for solar radiation for thermal absorption. The absorber has a dome-shaped entry window made of quartz glass, wherein the inner side facing the absorber assumes a nominal interior temperature Ti of at least 950° C. during proper use, preferably at least 1000° C., whereas the outer side facing away from the absorber is exposed to the environment and subject to risk of devitrification. The invention relates to modifying the known solar radiation receiver so that a high absorber temperature can be set and thus a high efficiency of the solar thermal heating is enabled, without increasing the risk of devitrification in the region of the outer side of the entry window.

Abstract: A method for producing a mirror substrate blank made from titanium-doped silica glass for EUV lithography, having a thickness of at least 40 millimeters, includes steps of face grinding the surface of the blank and identifying data on defects in a surface layer of the blank. Light penetrates the blank at a predetermined angle of incidence ? of less than 90° at a location on the flat surface of the blank. The light scatters on a defect in the blank, and the scattered light is detected at a distance x from the penetration location on the surface of the blank by a light detection element arranged perpendicularly thereabove. The method further includes steps of determining the position of the defect in the surface layer based on the obtained data, and partial or complete removal of the surface layer in consideration of the position determination and forming the mirror substrate blank.

Abstract: A method for manufacturing quartz glass, wherein (a) an appropriate liquid starting material is evaporated by spraying it into a vertically arranged evaporation chamber, (b) the vaporous starting material is oxidized to form SiO2, and the SiO2is collected. The method is characterized in that the starting material to be evaporated is sprayed in on the bottom of the evaporation chamber and the vaporous starting material is removed at the top end of the evaporation chamber, wherein the evaporation chamber is designed such that components depositing in the chamber accumulate on the bottom of the evaporator and are sprayed once again, as well as an evaporator for applying the method.

Abstract: In one method for producing opaque quartz glass, a green body is produced from a slip containing fine, amorphous SiO2 particles and coarse SiO2 reinforcement bodies and the green body is sintered by way of a sintering treatment into a blank made from the opaque quartz glass. The reinforcement bodies with a specific density DK1 are here embedded in a SiO2 matrix with a specific glass density DM. Starting from this, in order to provide a blank of opaque quartz glass that is less susceptible to cracking and illustrates homogeneous transmission even in the case of small wall thicknesses, in one aspect sinterable reinforcement bodies are used, the specific density DK0 of which prior to the sintering treatment is lower than the specific glass density DM, and which due to the sintering treatment reach the specific density DK1 which differs from the specific glass density DM by less than 10%.

Abstract: The invention relates to a method for economically producing a composite powder made of carbon and electrochemical active material. According to the invention, a melt made of a meltable carbon precursor substance having nanoparticles made of an active material distributed in the melt is provided, and said melt is divided into the composite powder, in which nanoparticles made of the active material are embedded in a matrix made of the carbon precursor substance. A porous composite material produced using the composite powder is used to produce an electrode for a secondary battery, in particular for use as an anode material.

Abstract: A method and apparatus are provided for producing a tube of glass by zonewise heating and softening of a hollow cylinder by a movable heating zone while rotating about its rotation axis. The glass tube is continuously formed by radial expansion of the softened region under action of centrifugal force and/or internal overpressure applied in the hollow-cylinder bore. The method and apparatus make it possible to deform the hollow cylinder in a single or a small number of forming steps into a glass tube having a larger outer diameter and high dimensional accuracy by determining a circumferential position at which the wall thickness is comparatively small, and during heating and softening of the rotating hollow cylinder a coolant is dispensed from a coolant source onto the deformation zone only when or predominantly when the circumferential position having the comparatively small wall thickness passes the coolant source.

Abstract: In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm3, and at a temperature of 1000° C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 ?m.

Abstract: A method for producing a component includes joining individual wall parts, especially for producing a melting crucible for use at a high operating temperature in a crucible-pulling method for quartz glass, wherein at least two wall parts of a refractory metal or of a base alloy of a refractory metal are provided, butt-joined to form a joint and joined together by sintering at a temperature above 1500° C. to form the component. A sealant is inserted into the joint to provide a component of improved tightness and to ensure improved sintering of the individual parts of the component. A component produced according to the method, particularly a melting crucible, particularly in a crucible pulling method for quartz glass, has the joint between the butt-joined walls closed in a gas-tight manner by a sealant.

Abstract: One aspect relates to a method for producing an optical blank from synthetic quartz glass by vitrifying and shaping a porous, cylindrical SiO2 soot body having a longitudinal axis, in a heating zone including a melt mold with bottom plate. The SiO2 soot body vitrified in the heating zone at a vitrification temperature so as to form a fully cylindrical, completely vitrified, transparent quartz glass body. Subsequently, the vitrified quartz glass body is shaped by softening in the melt mold at a softening temperature so as to form a viscous quartz glass mass which partly fills the volume of the melt mold, and cooling the quartz glass mass and removal from the melt mold so as to form the optical blank. During shaping in the melt mold, the fully cylindrical quartz glass body is brought into contact by way of controlled supply with a centering means of the bottom plate.

Abstract: A UV lamp including a filter material of doped quartz glass is provided that effects a transparency as high as possible for operating radiation in the ultraviolet spectral range above 210 nm together with low transparency in the wavelength range below about 190 nm. The filter material of doped quartz glass includes at least 99 wt. % of SiO2 and Al2O3, wherein the Al2O3 portion is in the range of 2 wt. % to 4 wt. The filter material has an edge wavelength at a wavelength below 190 nm and a spectral transmission of 80% mm?1 or higher at a wavelength of 210 nm.

Abstract: The invention relates to a process for producing SiO2 granules by freezing and re-thawing an SiO2 suspension, wherein a separation of liquid and sediment composed of agglomerated SiO2 particles occurs in the course of thawing, the liquid removed is decanted and the residual moisture in the sediment is removed by a drying step with formation of the SiO2 granules. According to the invention, an auxiliary comprising alkali metal-free bases in the form of nitrogen hydrides is added to the suspension to set the pH greater than 7.

Abstract: One aspect relates to a method for the manufacture of doped quartz glass. Moreover, one aspect relates to quartz glass obtainable according to the method including providing a soot body, treating the soot body with a gas, heating an intermediate product and vitrifying an intermediate product.

Abstract: In a known method for pulling a semiconductor single crystal according to the Czochralski method, a semiconductor melt is produced in a silica glass crucible and the semiconductor single crystal is pulled from said melt. The inner wall of the silica glass crucible and the exposed melt surface are in contact with one another and with a respective melt atmosphere in the region of a contact zone running radially around the crucible inner wall, and primary oscillations of the melt are triggered in said contact zone. On this basis, in order to provide a method characterized by reduced melt vibrations and in particular by a simple, short accretion process, according to the invention primary oscillations are triggered which differ from one another in their frequency.

Abstract: An optical component made of synthetic quartz glass includes a glass structure substantially free of oxygen defect sites and having a hydrogen content of 0.1×1016 to 1.0×1018 molecules/cm3, an SiH group content of less than 2×1017 molecules/cm3, a hydroxyl group content of 0.1 to 100 wt. ppm, and an Active temperature of less than 1070° C. The optical component undergoes a laser-induced change in the refractive index in response to irradiation by a radiation with a wavelength of 193 nm using 5×109 pulses with a pulse width of 125 ns and a respective energy density of 500 ?J/cm2 at a pulse repetition frequency of 2000 Hz. The change totals a first measured value M193 nm when measured using the applied wavelength of 193 nm and a second measured value M633 nm when measured using a measured wavelength of 633 nm. The ratio M193 nm/M633 nm is less than 1.7.