Abstract: A method of mining rock utilizes a high-intensity electron beam to break the rock. The electron beam is directed onto the surface of the rock, and has sufficient energy either to ablate the rock at the zone of beam impingement and generate an ablation pressure that is sufficiently high to fracture the rock or to expand thermally the rock and generate a dynamic pressure in a lateral direction to fracture the rock. The electron beam is moved along the surface of the rock at a speed in phase with the speed of crack propagation in the rock.

Abstract: Gas delivery means for providing a flow of gas to the kerf in a workpiece which is being cut by a beam of laser radiation is disclosed. The distribution means consists of a thin wafer which is placed in the path of the cutting beam adjacent to the workpiece and a stream of gas directed along the axis of laser propagation blows the kerf clean. An upper gas port and a lower gas port allow the laser radiation to pass through the wafer without any transmissive optics. Use of the gas delivery means with various gases at high pressure and with laser beams at power levels which were previously impractical are discussed.

Abstract: A method and arrangement for curing paint films and coating compositions by means of infrared radiation emitted by IRASERS, whereby the intensity of the IRASER beam is determined or controlled by the simultaneous measurement of the surface temperature of the coating being cured, and programs therefor, are described. Uniformity of cure of the paint films and coating compositions is obtained.

Abstract: An apparatus consisting in forming, with the oxide to be sprayed on, a plasma in an arc state within a source cavity. The state is stabilized by various known methods but which are well-adapted and the substrate to be covered is preferably kept at a predetermined distance, in order of 50 cm, from the source cavity.A positive pressure gas is supplied to the source cavity and vacuum pressure is maintained in the enclosure supporting the substrate facing the cavity opening to deposit oxide uniformly at high speed.

Abstract: A method of cutting a multilayer pile of sheet material with a beam of laser radiation is disclosed. A laser beam having a low order mode intensity distribution is focused onto the pile and during cutting a stream of liquid coolant is directed into the material vaporization region to absorb energy from the outer region of the mode distribution which could otherwise result in adhesion of adjacent layers, globularization, singeing or other undesired effect.

Abstract: Apparatus which may be mounted upon a lay barge to weld an end of a pipe spool to an end of a pipeline used under water, includes a stand fixed to the pipeline to support and secure its outer end, a pipe spool support which may hold a spool in coaxial relationship with the pipeline and with one end abutting the outer end of the pipeline, a laser positioned to direct a beam of coherent radiation along the axis of the pipeline, a reflection system including a mirror mounted for movement through an arc of 360.degree. in the path of the laser beam to reflect that beam radially on the abutting ends of the pipeline and pipe spool, and a laser energy source for generating a beam of sufficient intensity to weld together the abutting ends of the pipeline and the pipe spool.

Abstract: A method and apparatus are disclosed for removing nuclear fuel from a clad fuel element. The fuel element is power driven past laser beams which simultaneously cut the cladding lengthwise into at least two longitudinal pieces. The axially cut lengths of cladding are then separated, causing the nuclear fuel contained therein to drop into a receptacle for later disposition. The cut lengths of cladding comprise nuclear waste which is disposed of in a suitable manner.

Abstract: A method of accomplishing a controlled weld with a beam of laser radiation is disclosed. The workpiece is cleaned and fitted prior to joining and a flow of a gas is provided in the weld region to prevent the formation of radiation insulating plasma between the laser source and the workpiece and to aspirate gaseous impurities from the weld zone. In addition, a trailing cover gas is provided to both the top and the bottom of the weld until the joint is sufficiently cooled to prevent reaction between the metal and the atmosphere. The beam must contain more than two kilowatts of power and be focusable on the workpiece to a power density of at least one megawatt per square inch in order to produce a keyhole in the fusion zone. Further, a weld speed in excess of twenty inches per minute and a progressive solidification technique of the weld contribute to the expulsion of contaminants from the weld.

Abstract: A beam generating tube in a welder has an anode connected to ground potential and a cathode-Wehnelt electrode circuit connected across a portion of a voltage divider which is connected to a high voltage source. The voltage drop across the portion of the voltage divider is varied by means of a control tube connected in parallel with that portion, the voltage at the control electrode of the control tube being varied as a function of the difference between the actual beam current and the desired beam current as set externally. A diode is connected from the cathode of the beam generating tube to the voltage divider tap so that the voltage drop across the control tube is limited when the welder is not in operation and no current flows from the voltage divider tap to the control tube when the welder is in operation. When the difference between the actual beam current and the desired beam current exceeds a predetermined difference, the energization of the beam generating tube is interrupted.

Abstract: A method whereby defect-free welds can be produced in joining metallic members of dissimilar materials by electron-beam welding. The method consists in inserting one of the metallic members in openings formed in a metallic plate of the same material as the other metallic member and welding one metallic member to the metallic plate by providing a weld metal, providing by overlay welding on the weld metal a padding metal of a material substantially similar to that of the other metallic member but lower in oxygen content, effecting machining of the outer surface of the padding metal to form a faying surface, and joining by electron beam welding the faying surface of the padding metal to a faying surface formed on the other metallic member whereby the faying surfaces can be rigidly welded.

Abstract: A method for welding dissimilar metals, wherein the end of one of said dissimilar metals is welded to a metal plate by using a filler metal, the material of said metal plate being the same as that of another of said dissimilar metals; and electron beam welding is applied along the interface formed between such a joint surface of said metal plate, which does not include the aforesaid welded portion, and the joint surface of another of said dissimilar metals.

Abstract: In a method for striking a main arc between the electrode and nozzle of a plasmatron there is initiated with the aid of high-frequency discharge an intermittently-arcing pilot arc whose flame bridges under the influence of a gas fed into the plasmatron the gap between the electrode of plasmatron and workpiece, completing thereby the circuit of main arc. The amplitude of pilot arc current is selected so as to be roughly equal to the steady current of the main arc whereas the frequency and on-off time ratio of the current are selected so as to assure that the flame of pilot arc is sustained unceasingly throughout the arcing of visually-monitored pilot arc.

Abstract: An apparatus for forming grooves in a semiconductor wafer by the use of a laser beam includes a movable stage on which the wafer is mounted and a transparent member mounted on the stage in a sealed manner and covering the wafer. A liquid is introduced into the space defined between the wafer and the transparent member.

Abstract: Millimeter-wave electronic devices are produced first by micromachining an epitaxial layer on a substrate wafer to a precise thickness by directing an ion beam over the epitaxial layer. Any bombardment damage is removed by a light chemical etch. Thereafter, an insulative layer with a mask is placed over the micromachined epitaxial layer and the ion beam is broadly directed onto the masked wafer to micromachine precise holes through unmasked portions of the insulative layer. Micromachining may proceed until approximately 500 A thickness of the insulative layer remains, this remaining layer being removed by a brief chemical etch to expose the underlying epitaxial layer. Alternatively, in cases where a slight recess into the semiconductor is desired to alter the electric field lines at the interface between the oxide and the semiconductor, the ion beam may be permitted to etch completely through the oxide film and into the epitaxial layer to the desired depth.

Abstract: A plasma flame-spraying apparatus, having a source of primary gas and a source of a secondary plasma gas, is provided with means for insuring that when the secondary gas in passed through the electric arc established in the flame-spraying apparatus, which secondary gas flow causes an increase in the voltage in the current of the circuit containing the arc, the current is suitably adjusted. The apparatus includes means for insuring that the ignition of the arc is established by pressing a single switch. There is also provided a closed loop system of determining the voltage changes in the arc circuit and for compensatingly regulating the current at a fixed plasma gas flow-through rate and composition to maintain a desired balance between current and secondary gas flow. Various automatic means are provided for insuring against excessive constriction of the confined electric arc within the nozzle of the apparatus or parts associated therewith.

Abstract: A method for welding dissimilar metals, wherein a filler metal is deposited on one end of the aforesaid dissimilar metals to be jointed, said filler metal being of the same material as that of another of said dissimilar metals; the outer surface of the weld metal thus deposited is machined to provide a joint surface adapted for welding; and an electron beam welding is applied along the interface formed between said joint surface of said weld metal thus deposited and the joint surface of another of said dissimilar metals.

Abstract: In an electron beam-generating system including an electron-emitting cathode, a beam focusing electrode, and an anode electrode for accelerating the emitted electrons, the magnetic fields for deflecting the beam to material to be heated and for periodically deflecting the focal spot of the beam on the material are produced by a heavy current conductor, that is, a conductor carrying a high current, arranged in proximity to the curved path of the deflected electron beam and extending perpendicular to the plane of deflection of the electron beam. The anode electrode may be formed with an opening for the passage of the electron beam, and the heavy current conductor is arranged in the proximity of the opening and parallel to the latter. The heavy current conductor may be designed as an edge of a slot-shaped opening, and may comprise a plurality of individual conductors.

Abstract: A method of manufacturing an orifice delay valve having an apertured plate which is formed by coining a section in the plate, eroding a portion of the coined section by electrical discharge machining followed by ultra-sonic cleaning of the plate.

Abstract: A wafer of semiconductor material having a plurality of units defined on its face is subdivided by treating the wafer, on its back or reverse side, in the kerf regions between the units, where division of the units is desired, such that the material of the wafer in the treated kerf regions is converted to a material having a breaking strength lower than the breaking strength of the semiconductor material.

Abstract: A plasma-MIG welding method and device in which a stream of oxidizing gas, such as argon plus 2% oxygen, is introduced into the plasma arc in the region of the plasma nozzle orifice. This improves the stability of the MIG arc, and higher welding currents can be used, especially with negative polarity on the electrodes and the plasma and MIG arcs.