Abstract: An object of the invention is to provide an electron microscope capable of obtaining a sufficient energy resolution without forming a long drift space and capable of attaining high energy discrimination detection performance with approximately the same device size as in the related art. The electron microscope according to the invention includes a pulsed electron emission mechanism configured to emit an electron beam in a pulsed manner, and discriminates energy of signal electrons by discriminating the signal electrons, which are emitted from a sample by irradiating the sample with the electron beam, according to a time of flight (see FIG. 2).

Abstract: When the surface of a semiconductor wafer, a photomask or the like sample is charged by irradiation with a charged particle beam, the charging is liable to hamper image observation, inspection and handling. Therefore, the sample and the surface or vicinity of the sample being charged by an electron beam or the like is held in an atmosphere or a reduced pressure atmosphere or in a predetermined gaseous atmosphere within a preliminary evacuation chamber, a sample chamber or the like, containing a soft X-ray generator which irradiates the sample or the vicinity thereof with soft X-rays which are controlled to generate positive ions and negative ions and remove charges on the surface of the sample.

Abstract: A scanning pattern drawing apparatus which scans the surface of a workpiece with a light beam so that a pattern is described on the workpiece with the issued light beam being controlled on the basis of pattern drawing data stored in a pattern memory, wherein the pattern drawing apparatus is able to read many pieces of data in a short period of time even if the frequency of the timing pulses is reduced and which therefore is capable of drawing a precise pattern on a workpiece. A scanning pulse generator produces as scanning pulse in response to a predetermined amount of scanning with the light beam. The scanning pulse is converted to a plurality of resulting timing pulses, and successive parallel outputs of the timing pulses are produced after delaying by a predetermined time. The pattern drawing data is read from the pattern memory in response to the delayed timing pulses.

Abstract: A drawing surface adjusting mechanism suitable for use with a large scanning pattern drawing apparatus in which a scanning optical system scans drawing rays of light along scanning lines on a workpiece on a drawing board. A plurality of light-emitting units project rays of light in a wavelength region outside a sensitivity range of the workpiece onto a drawing surface of the workpiece in such a way that the rays substantially converge at more than one point along a scanning line of the drawing rays of light, preferably at center and end points along the scanning line. A plurality of condenser lenses are provided for focusing beams of light from the plural light-emitting units after the beams have been reflected by the drawing surface. A plurality of light-detecting elements are disposed at points of condensation by respective ones of the condenser lenses to produce output signals representing differences in condensation points that occur as the lenses depart from or approach the drawing surface.

Abstract: An apparatus for correcting a scranning beam produced by a polygonal mirror tilting in small surface segments in each mirror surface segment caused by uneven mirror surfaces of the polygonal mirror. Data indicative of the amount of tilting in each of the surface segments is stored in a memory, which is addressed by a data signal indicative of the present scanning position of the polygonal mirror. Output data from the memory is applied to an acousto-optical modulator disposed in the beam path between the light source and the polygonal mirror.

Abstract: A monitor mechanism for use with a scanning optical apparatus in which the direction of polarization is utilized to separate a source laser light beam into a pattern drawing and a monitor beamlet and to synthesize them again into a single after passing through a scanning lens and beam deflector. The two beamlets can thus be controlled so as to project towards the deflector and scanning lens in the same direction, which is effective in reducing the offset between the pattern drawing and monitor beams that may occur on account of such factors as variations in lens performance.

Abstract: A drawing surface adjusting mechanism for use with a scanning pattern drawing apparatus capable of not only moving a drawing board in a vertical direction but also tilting it, whereby the chance of bringing the drawing surface within the depth of focus of a scanning lens is increased even if the drawing surface has waviness or other flaws within the width of a single storke of scanning.

Abstract: A table assembly that is simple in construction and which yet resists yawing in an effective way and is adapted for use with a scanning pattern drawing apparatus which involves continuous movements of the table. The inventive table assembly includes a master table that is slidable in one direction with respect to a fixed portion of the overall assembly and to which a drive force for causing the table to slide in the one direction is transmitted directly, and a working table that is slidable in the one direction with respect to the fixed portion and which is linked to the master table by connecting means having rigidity in the one direction and elasticity in a direction perpendicular to the one direction.

Abstract: A process for the selective production of petrochemical products by thermal cracking is disclosed. The process includes feeding methanol to a thermal cracking atmosphere of hydrocarbons in such a way that the ratio, as carbon atoms, of methanol and at least one starting hydrocarbon is at least 0.05:1, thermally cracking the at least one starting hydrocarbon at a cracking temperature of from 650.degree. to 1300.degree. C., and quenching the resulting reaction product.

Abstract: A process for selectively producing olefins and aromatic hydrocarbons by thermal cracking of hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding a heavy hydrocarbon to the hot gas to thermally crack the heavy hydrocarbon under conditions of a temperature not lower than 1000.degree. C., a pressure not higher than 100 kg/cm.sup.2 g, and a residence time of from 5 to 20 milliseconds; further feeding a light hydrocarbon downstream of the feed of the heavy hydrocarbon in such a way that a light hydrocarbon with a lower boiling point is fed at a lower temperature side downstream of the feed of the heavy hydrocarbon, thereby thermally cracking the light hydrocarbon under conditions of a reactor outlet temperature at not lower than 650.degree. C., a pressure at not higher than 100 kg/cm.sup.

Abstract: A thermal cracking process for producing petrochemical products from hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding a mixture of methane and hydrogen to the hot gas in such a way that a methane/hydrogen molar ratio is over 0.05; further feeding starting hydrocarbons to the hot gas comprising the methane, hydrogen and steam so that the starting hydrocarbons containing hydrocarbon components of higher boiling points are, respectively, fed to higher temperature zones; subjecting the starting hydrocarbons to thermal cracking while keeping the cracking temperature at 650.degree. to 1500.degree. C., the total residence time at 5 to 1000 milliseconds, the pressure at 2 to 100 bars, and the partial pressure of hydrogen, after thermal cracking of a hydrocarbon comprising hydrocarbon components whose boiling point exceeds 200.degree. C., at least 0.

Abstract: A thermal cracking process for producing olefins from hydrocarbons which comprises the steps of burning hydrocarbons with less than the theoretical amount of oxygen in the presence of steam to give a hot gas of from 1400.degree. to 300.degree. C. comprising steam and hydrogen prior to reaction; feeding to the hot gas comprising the steam and hydrogen, a mixture of methane and hydrogen so that a methane/hydrogen molar ratio in said hot gas is over 0.05; further feeding a starting hydrocarbon to the hot gas mixture comprising the methane, hydrogen and steam; subjecting the starting hydrocarbon to thermal cracking while keeping the partial pressure of hydrogen at least 0.1 bar at the outlet of a reactor, the temperature at 800.degree. to 1200.degree. C., and the residence time at 5 to 300 milliseconds; and quenching the resulting reaction product.

Abstract: In methods of manufacturing olefines by thermally cracking hydrocarbons, there is disclosed a thermal cracking method for producing olefines from hydrocarbons, characterized in that hydrocarbon in burnt with oxygen in the presence of steam to generate a high-temperature gas containing steam of 1500.degree.-3000.degree. C., methane and hydrogen are supplied into the high-temperature gas containing said steam, with the molar ratio of methane to hydrogen in said high temperature gas being 0.05 or more, then hydrocarbon to be cracked is supplied into said high-temperature gas containing said methane, hydrogen and steam, so that the hydrocarbon is subjected to thermal cracking by maintaining the partial pressure of hydrogen at more than at least 0.1 bar at the outlet of a reactor, under conditions of reaction temperature, 800.degree.-1200.degree. C. and residence time in the reactor 5-300 milli second, and then the reaction product is cooled in a rapid manner.

Abstract: A thermal cracking process for selectively producing petrochemical products from hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300.degree. to 3000.degree. C. comprising steam; feeding hydrogen to the hot gas; further feeding starting hydrocarbons to the hot gas comprising the steam and hydrogen so that the starting hydrocarbons containing hydrocarbon components of higher boiling points are, respectively, fed to higher temperature zones so as to thermally crack the respective hydrocarbons under different conditions while keeping the cracking temperature at 650.degree. to 1500.degree. C., the total residence time at 5 to 1000 milliseconds, the pressure at 2 to 100 bars, and the partial pressure of hydrogen, after thermal cracking of a hydrocarbon comprising hydrocarbon components whose boiling point exceeds 200.degree. C., at least 0.1 bar; and quenching the resulting reaction product.

Abstract: In methods of manufacturing olefines by thermally cracking hydrocarbons, there is disclosed a thermal cracking method for producing olefines from hydrocarbons, characterized in that hydrocarbon is burnt with oxygen in the presence of steam to generate a high-temperature gas containing steam of 1500.degree.-3000.degree. C.; methane and hydrogen are supplied into the high-temperature gas containing said steam, with the molar ratio of methane to hydrogen in said high-temperature gas being 0.05 or more, then hydrocarbon to be cracked is supplied into said high-temperature gas containing said methane, hydrogen and steam, so that the hydrocarbon is subjected to thermal cracking by maintaining the partial pressure of hydrogen at more than at least 0.1 bar at the outlet of a reactor, under conditions of reaction temperature, 800.degree.-1200.degree. C. and residence time in the reactor 5-300 milli second, and then the reaction product is cooled in a rapid manner.

Abstract: A thermal cracking process for producing olefins from hydrocarbons which comprises the steps of burning hydrocarbons with less than the theoretical amount of oxygen in the presence of steam to give a hot gas of from 1400.degree. to 300.degree. C. comprising steam and hydrogen prior to reaction; feeding to the hot gas comprising the steam and hydrogen, a mixture of methane and hydrogen so that the methane/hydrogen molar ratio in said hot gas is over 0.05; further feeding a starting hydrocarbon to the hot gas mixture comprising the methane, hydrogen and steam; subjecting the starting hydrocarbon to thermal cracking while keeping the partial pressure of hydrogen at least 0.1 bar at the outlet of a reactor, the temperature at 800.degree. to 1200.degree. C., and the residence time at 5 to 300 milliseconds; and quenching the resulting reaction product.