Abstract: A method for determining the refractive index profile of a preform is provided.

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: A method for determining the refractive index profile of a preform is provided.

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.

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: Starting from an optical component of quartz glass for transmitting ultraviolet radiation of a wavelength between 190 nm and 250 nm, with a glass structure essentially without oxygen defects, a hydrogen content ranging from 0.1×1016 molecules/cm3 to 5.0×1016 molecules/cm3, and with a content of SiH groups of less than 5×1016 molecules/cm3, to provide such a component which is particularly well suited for use with linearly polarized UV laser radiation, the present invention suggests that the component should have a content of hydroxyl groups ranging from 10 to 250 wt ppm and a fictive temperature above 1000° C.

Abstract: Starting from an optical component of quartz glass for transmitting ultraviolet radiation of a wavelength between 190 nm and 250 nm, with a glass structure essentially without oxygen defects, a hydrogen content ranging from 0.1×1016 molecules/cm3 to 5.0×1016 molecules/cm3, and with a content of SiH groups of less than 5×1016 molecules/cm3, to provide such a component which is particularly well suited for use with linearly polarized UV laser radiation, the present invention suggests that the component should have a content of hydroxyl groups ranging from 10 to 250 wt ppm and a fictive temperature above 1000° C.

Abstract: An agricultural machine having at least one crop processing work unit, a plurality of crop transport units operatively assembled as a straw walker step, wherein the crop transport units convey crop streams in opposite directions and are spaced apart defining a crop through-gap, and a cleaning device having a forced-draught fan before the cleaning device, further comprising an exhaust fan located after the cleaning device, wherein the transport units are located between the forced-draught fan and the exhaust fan, wherein an air stream is produced by the forced-draught fan and the exhaust fan and is directed from the forced-draught fan to the exhaust fan, and wherein the air stream improves a cleaning process in the straw walker through-gap of the straw walker step.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction. The quartz glass blank according to the invention is characterized by the following properties: a glass structure essentially free of oxygen defect sites, an H2-content in the range of 0.1×1016 molecules/cm3 to 4.0×1016 molecules/cm3, an OH-content in the range of 125 wt-ppm to 450 wt-ppm, an SiH group-content of less than 5×1016 molecules/cm3, a refractive index inhomogeneity, ?n, of less than 2 ppm, and a stress birefringence of less than 2 nm/cm.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction. The quartz glass blank according to the invention is characterized by the following properties: a glass structure essentially free of oxygen defect sites, an H2-content in the range of 0.1×1016 molecules/cm3 to 4.0×1016 molecules/cm3, an OH-content in the range of 125 wt-ppm to 450 wt-ppm, an SiH group-content of less than 5×1016 molecules/cm3, a refractive index inhomogeneity, ?n, of less than 2 ppm, and a stress birefringence of less than 2 nm/cm.

Abstract: The present invention concerns a quartz glass blank for an optical component for the transmission of ultraviolet radiation of a wave length of 250 nm and under, as well as its utilization in microlithography in connection with ultraviolet radiation of a wavelength of 250 nm and under. Such quartz glass blank is to have low induced absorption, while being optimized in respect of compaction and de-compaction. The quartz glass blank according to the invention has the following properties: A glass structure essentially free of oxygen defect sites; a H2 content in the range of 3×1017 molecules/cm3 to 2.0×1018 molecules/cm3; an OH content in the range of 500 weight ppm to 1000 weight ppm; a SiH group content of less than 2×1017 molecules/cm3; a chlorine content in the range of 60 weight ppm to 120 weight ppm; a refractive index inhomogeneity, ?n, of less than 2 ppm; and a stress birefringence of less than 2 nm/cm.

Abstract: The invention relates to a previously known method for producing synthetic silica glass, comprising the following steps: a gas stream containing a vaporizable initial substance, which can be converted into SiO2 by means of oxidation or flame hydrolysis, is formed; the gas stream is delivered to a reaction zone in which the initial substance is converted so as to form amorphous SiO2 particles; the amorphous SiO2 particles are deposited on a support so as to form an SiO2 layer; and the SiO2 is vitrified during or following deposition of the SiO2 particles in order to obtain the silica glass. The aim of the invention is to create an economical method for producing synthetic silica glass, which is characterized by a favorable damaging behavior towards short-wave UV radiation while being particularly suitable for producing an optical component used for transmitting high-energy ultraviolet radiation having a wavelength of 250 nm or less.

Abstract: Starting from an optical component of quartz glass for transmitting ultraviolet radiation of a wavelength between 190 nm and 250 nm, with a glass structure essentially without oxygen defects, a hydrogen content ranging from 0.1×1016 molecules/cm3 to 5.0×1016 molecules/cm3, and with a content of SiH groups of less than 5×1016 molecules/cm3, to provide such a component which is particularly well suited for use with linearly polarized UV laser radiation, the present invention suggests that the component should have a content of hydroxyl groups ranging from 10 to 250 wt ppm and a fictive temperature above 1000° C.

Abstract: A method for producing an optical component for transmitting ultraviolet radiation of a wavelength of 250 nm and shorter, wherein the component is made from a cylindrical quartz glass blank having a mean OH content of more than 50 wt ppm, which is subjected to a first annealing treatment for eliminating stress birefringence, characterized in that the quartz glass blank is subjected to a second annealing treatment which comprises heating up and holding the quartz glass blank at a low annealing temperature ranging from 350° C. to 800° C. and for an annealing period of more than 1 hour, with the proviso that a quartz glass blank is used in which in a direction perpendicular to the cylindrical longitudinal axis the deviation from the mean OH content is not more than 20 wt ppm.

Abstract: An agricultural machine having at least one crop processing work unit, a plurality of crop transport units operatively assembled as a straw walker step, wherein the crop transport units convey crop streams in opposite directions and are spaced apart defining a crop through-gap, and a cleaning device having a forced-draught fan before the cleaning device, further comprising an exhaust fan located after the cleaning device, wherein the transport units are located between the forced-draught fan and the exhaust fan, wherein an air stream is produced by the forced-draught fan and the exhaust fan and is directed from the forced-draught fan to the exhaust fan, and wherein the air stream improves a cleaning process in the straw walker through-gap of the straw walker step.

Abstract: An agricultural machine having at least one crop processing work unit, a plurality of crop transport units operatively assembled as a straw walker step, wherein the crop transport units convey crop streams in opposite directions and are spaced apart defining a crop through-gap, and a cleaning device having a forced-draught fan before the cleaning device, further comprising an exhaust fan located after the cleaning device, wherein the transport units are located between the forced-draught fan and the exhaust fan, wherein an air stream is produced by the forced-draught fan and the exhaust fan and is directed from the forced-draught fan to the exhaust fan, and wherein the air stream improves a cleaning process in the straw walker through-gap of the straw walker step.

Abstract: An agricultural harvesting machine has a comminuting device which includes a chopper rotor having a rotor shaft, and a conveying element pivotably connected with the rotor shaft. The conveying element is formed by a first arm and a second arm which are interconnected by a cross web. In one embodiment the cross web has a recess between the first and second arms, and a cutting element is provided which passes either through the recess of the conveying element or outside of the first and second arms of conveying element as the conveying element rotates. In another embodiment the conveying element is provided with both leading and trailing cutting edges arranged in sets. Initially one set of cutting edges is utilized and the conveying element can latter be reversed in position to utilize the other set.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction.

Abstract: The present invention concerns a quartz glass blank for an optical component for the transmission of ultraviolet radiation of a wave length of 250 nm and under, as well as its utilization in microlilthography in connection with ultraviolet radiation of a wavelength of 250 nm and under. Such quartz glass blank is to have low induced absorption, while being optimized in respect of compaction and de-compaction.