Abstract: The disclosed invention relates to a video display system having a device for shielding electromagnetic radiation emitted from electrical wires which connect a video amplifier to a cathode ray tube. The device uses inexpensive unshielded wires which are recessed within a conductive shielding enclosure. The wires are connected to the cathode ray tube by a socket which is positioned at an access opening in the shielding enclosure. The invention further relates to a device for mounting a shielding enclosure to a base using tabs on the enclosure which are captured in an interference fit between the surface of the base and brackets coupled to the base.

Abstract: A magnetron for a microwave includes a pair of choke coils wound around only one core in same direction thereby forming a unique type choke coil. Ends of the unique type choke coil are connected among a lead-through capacitor, a center lead and a peripheral lead respectively so that the filter circuit includes jointly the unique choke coil. As a result, the magnetron can eliminate radio frequency noise, reduce the heating caused from a power supply, and reduce the volume of the filter box.

Abstract: A shielded CRT (18) display includes a secondary shielding enclosure (14) for enclosing the CRT (18) and for inhibiting electromagnetic emissions therefrom. A primary shielded enclosure (12) internal to the secondary shielding enclosure (14) has a portion coaxial (16) with the neck portion (22) of the CRT (18) for also inhibiting electromagnetic emissions from the CRT (18). The CRT (18) includes an internal conductive layer comprised of an internal aquadag, wire mask, and phosphor coating. This internal conductive layer is grounded via a reactive path to ground to suppress electromagnetic emissions. This double shielding suppression technique eliminates the need for external shielding of the face portion of the CRT (18).

Abstract: The circuit includes a probe (6) for detecting a horizontal magnetic field and a first and a second circuit means (15, 17) driven by said probe (6) so as to create respective axial and lateral components of compensation of the horizontal magnetic field, that are in the same direction and of equal intensity, but of opposite sign to that of the magnetic field under test.

Abstract: A compensating coil for a scanning electron beam display such as a color television tube reduces undesirable deflection of the electron beams due to ambient magnetic fields, in particular the geomagnetic field. A first coil section has at least one winding disposed to encircle the tube neck, perpendicular to the Z axis. Upper and lower coil sections are disposed above and below the first coil section, each inclined forwardly along the Z axis and having a loop encompassing an area extending in the X and Y directions generally following the surface of an internal magnetic shield. The coil sections are coupled in series. The upper and lower coil sections have a wider X axis dimension proceeding forwardly along the Z axis, being keystone shaped. Lateral lengths of the upper and lower coils sections connect to the first coil section at lateral sides, such that the compensating coil is a continuous winding. The first coil section may have two passes for each pass of the upper and lower coil sections.

Abstract: A compensating coil for a scanning electron beam display, such as a color television tube, reduces undesirable deflection of the electron beams due to ambient magnetic fields, in particular the geomagnetic field. The coil has a winding disposed to encircle the tube neck, perpendicular to the Z axis. A degaussing coil is positioned on the tube envelope to provide for demagnetizing metal structures within the envelope. In order to provide more complete degaussing, the supply current to the compensating coil is interrupted during the degaussing operation. In order to prevent a charge from accumulating on the compensating coil, one terminal is coupled through a resistor to a source of reference potential.

Abstract: Video signals for each primary color are delayed in time relative to every other primary color video signals. When displayed on a cathode ray tube ("CRT") display, the time delayed video signals will result in a separated color pattern for each image displayed. Separated color images are subsequently realigned through use of electron beam deflection controls affecting the horizontal and vertical displacement of electron beams for each color. Measurement of EMI at a far field point varies between zero (no EMI) and no reduction in measurable EMI, depending on the frequency of the video signals and the amount of time delay induced therein. In alternative embodiments, time shifting of video signals may be accomplished either by discrete filter components, simple propagation delay lines.

Abstract: An electric field cancellation system and method for reducing electric fields are presented, especially suited for use in reducing the magnitude of electric field emissions from a CRT display. Signals from the electric field sources of the display are used to generate counter signals of equal magnitude and opposite polarity to the source signals. These counter signals are coupled to a plurality of transmitters which effectively establish a counter electric field, or fields, of opposite polarity to the source fields. The net effect is substantial reduction in the electric field emissions from the display, and a resultant electric field of substantially reduced magnitude encountered by a display operator.

Abstract: A demagnetizer for generating a degauss magnetic field to a cathode-ray tube by supplying an output of an AC power source to a degauss coil via a thermistor of positive characteristic, wherein a voltage-dependent resistance element is connected in parallel with the degauss coil so as to prevent generation of any excessive degauss magnetic field.

Abstract: A headlamp for a motor vehicle comprises a power unit including an inverter, a starting circuit connected to the inverter, an electric discharge lamp bulb connected to the starting circuit, and a shell for holding the starting circuit and the electric discharge lamp bulb. A lens and a cap are fixedly mounted to the shell at the front and rear open ends thereof, respectively. The shell and the cap are coated with a metal film to provide shielding from radio noise due to high frequency pulses.

Abstract: A method of manufacturing a display tube comprising an envelope having an envelope portion and a display window. The quantity of X-rays released from the envelope portion is determined, after which discrete X-ray absorbing means are provided in those places of the envelope where the quantity of X-rays released exceeds a limiting value. In a display tube manufactured according to such a method and comprising, in particular, a substantially rectangular display screen and a cylindrical neck portion having an electron gun the diagonals of the envelope of which are provided with discrete X-ray absorbing means, the desirable quantity of X-rays is absorbed in a simple and cost-effective manner.

Abstract: The present invention provides an apparatus and methods to reduce the stray magnetic fields created by the yoke assembly of a cathode ray tube (CRT) visual display device, and emitted from the CRT enclosure. A pair of closed wire loops are brought into contact with the yoke at the point where maximum magnetic radiation is emitted. The magnetic flux emitted from the yoke is coupled into the wire loop pair, inducing therein a current which flows so as to produce an opposing magnetic field to that produced by the CRT yoke. A capacitor in series in the second loop serves to increase the magnitude of the magnetic field produced by the second loop. Measured at a distance, the counteracting magnetic field reduces the total magnetic field emitted from the CRT enclosure.

Abstract: A video display has a flat panel display, and to reduce electric field radiation, includes a conducting shield having a transparent conducting surface overlying the display. The terminal is also shielded and wired to reduce magnetic field radiation.

Abstract: A system employing a stroboscopic light source permits an operator to remotely inspect and analyze high speed repetitive motion of machines. The system enables an operator to freeze motion or permit slow motion in either direction of moving parts in their natural environment. The system effectively shields the electronics incorporated in the light source by separating the electronics into sections and by utilizing a fiber optic cable to carry a control signal which control the firing of the flash lamp of the light source. In addition, the light source provides for control of the phase relationship between an external synchronization signal and a control signal which fires the flash lamp so that the timing of the flash can be controlled to stop a specific event in the cycle.

Abstract: A cathode ray tube has an insulating layer formed at at least a part of the outer surface of a neck tube.The insulating layer is a layer obtained by coating and baking a sol prepared by dispersing one or two or more metal alkoxides and metal salts in a hydrophilic oligomer state by adding water and an acid to a solution having one or two or more metal alkoxides and metal salts dissolved in an organic solvent such as an alcohol.

Abstract: In order to compensate for the influence of magnetic fields on charged-particle beams, in particular in imaging devices provision is made for a coil constituted by a support plate of substantially constant thickness and by patterns deposited on the support in such a manner as to ensure that the absorption of electromagnetic energy is constant over the entire surface of the coil within a predetermined pass-band.In a first embodiment, the patterns are transparent to the electromagnetic energy of a desired frequency band. In a second embodiment, complementary patterns are employed in order to obtain constant absorption over the entire surface of the coil.

Abstract: An electron beam apparatus has a cylindrical chamber, ion pump exhaust zones arranged in a substantially ring-like array, and an electron gun located on the center axis of the ring-like array, thereby minimizing the distance between the exhaust zone of an ion pump and the electron gun for generating an electron beam. Since the ion pump exhaust zones are located immediately next to the electron gun, it is therefore possible to achieve substantially the same vacuum level at the location of the electron gun as that at the ion pump per se.

Abstract: An arrangement for compensating against the magnetic field of the earth in a picture tube in remote-controlled video-display equipment, in which a compensating voltage is generated by a remote-control channel in the video-display equipment. This voltage is applied to a compensation coil in the picture tube. Current through the coil is adjusted in finely-divided incremental steps, and the current is continuously adjustable. The compensation voltage is applied to one end of the compensation coil, whereas the other end of the coil is supplied with substantially half of the operating voltage of the display equipment.

Abstract: A luminaire for an electrodeless high intensity discharge (HID) lamp includes passive and/or active electromagnetic interference (EMI) shielding apparatus. One embodiment of passive EMI shielding apparatus comprises at least one section of a conductive conical surface oriented so that its longitudinal axis is coincident with the envelope of the HID lamp. Currents are induced in the outer surface of the conductive cone-section, establishing a radio frequency magnetic field tending to eliminate the radio frequency magnetic field induced by current through the excitation coil of the lamp. Alternative or additional types of passive EMI shielding apparatus include a conductive disk having an opening for surrounding the envelope in the vicinity of the arc tube, and nested conductive cylinders. Active EMI shielding apparatus comprises a loop of wire for carrying a current in order to establish another magnetic field tending to reduce or eliminate EMI.

Abstract: A data processing display terminal utilizing a cathode ray tube (CRT) display is provided in which information-bearing electro-magnetic radiations are suppressed at the neck of the cathode ray tube and in the video circuits leading thereto, instead of mounting the entire display terminal in a shielded enclosure utilizing a piece of shielded glass over the CRT viewing area. A cylindrical shield is provided which completely encloses the socket and neck of the cathode ray tube, and extends to the proximity of the yoke of the CRT. A plurality of connectors are spaced about the cylindrical shield in the vicinity of the socket to accommodate connections to the socket. The video circuitry which carries the information desired to be displayed is completely shielded. The connectors in the cylindrical shield, with the exception of the video signal connector, are all provided with filters, and the video signal is coupled to the cylindrical shield connector by a shielded coaxial cable.

Abstract: A system for improving the operation of a cathode ray tube (CRT) is disclosed whereby interference caused by external magnetic fields is mitigated. The system comprises a CRT having a CRT magnetic shield housing and at least one electromagnetic field sensor disposed adjacent to the inner surface of the CRT housing. Sensors form to generate a reference magnetic field and to generate a sensor output signal in response to the detection of both the reference field and an external field as sensed within the housing. A bucking field coil drive circuit is provided in electrical communication with the field sensor, the drive circuit being operative to generate a bucking field coil drive signal responsive to the field sensor output signal. A bucking field coil is disposed circumferentially about the CRT and is driven by the bucking field coil drive signal.

Abstract: In a color picture tube apparatus, a deflection unit is provided around a color picture tube and a leakage magnetic is generated from the deflection unit. A metal cover made of aluminum, which covers an electrical power source is located in a space to which leakage magnetic field is reached and a first opposition magnetic field is generated from the metal cover due to the leakage magnetic field which produces an eddy current in the metal cover. A metal plate made of a conductive and non-magnetic material is so located between the deflection unit and the metal cover as to be substantially perpendicular to the metal cover. Thus, a second opposition magnetic field is so generated from the metal plate due to the leakage magnetic field as to substantially cancel the first opposition magnetic field.

Abstract: A gas discharge apparatus includes a discharge chamber including a transparent dome portion and an electrode-including base portion, which together enclose an ionizable gas. A cup-shaped base member is affixed at its periphery to the edge of the base portion of the discharge chamber. A power supply and discharge excitation network is disposed within the interior of the base portion. The power supply and discharge network include a pair of terminals. An oscillator and associated step-up output transformer powered from the terminals is positioned between the terminals and the discharge chamber. A field shield including a conductive sheet member is positioned between the terminals and the discharge chamber. The field shield is adapted to be electrically coupled to the electrode so that discharge-supporting electric fields may be established in the discharge chamber between the electrode and through the dome portion of that chamber to an effective ground electrode exterior to the chamber.

Abstract: In a television receiver, a magnetic field compensator of a horizontal component of the earth's magnetic field includes a fluxgate magnetometer having a pair of sensing windings for generating first and second sensing signals representative of corresponding components of the horizontal component of the earth's magnetic field. The sensing signals generate current in a pair of substantially planar coils disposed in a non-parallel vertical configuration on the rear periphery of a cathode ray tube. The currents in the coils produce a magnetic field that compensates or neutralizes the effect of the horizontal component of the earth's magnetic field on the electron beam in the cathode ray tube. Whenever the position of the receiver is changed, rotationally or geographically, the current in the coils is automatically adjusted to provide automatic neutralization.

Abstract: A picture display device having a display tube and a deflection unit comprising a field deflection coil and a line deflection coil is disclosed. To comply with a predetermined interference radiation standard, the picture display device is provided with one interference suppression coil or with a system of interference suppression coils, which interference supression coil or system of interference suppression coils is oriented and can be energized in such a manner that, measured at a predetermined distance from the picture display device, the strength of the local magnetic dipole field is below a desired standard.

Abstract: Disclosed is a method and apparatus for reducing radiated interference from a light source wherein a filter device is coupled across the light source after a predetermined time has expired from the starting of the light source. In this way, the filter does not interfere with the starting of the light source, however, after being coupled, the filter prevents radio frequency interference generated by the light source from radiating from the light source and associated wiring and interferring with nearby radio receiving equipment.

Abstract: A method of, and a device for, reducing the magnetic stray field generated in the vicinity of the faceplate of a cathode ray tube by the deflection current in the deflection coils of the tube. A current loop (4) is arranged at a distance from the deflection coils and is supplied with current having a time function substantially coinciding with the time function of the deflection current. The stray field is thereby neutralized to a large extent in a region extending beyond the position of the current conductor (4) in a direction away from the faceplate.

Abstract: Picture display device having a display tube and a deflection unit comprising a field deflection coil and a line deflection coil. To comply with a predetermined interference radiation standard, the picture display device is provided with one interference suppression coil or system of interference suppression coils is orientated and can be energized in such a manner that, measured at a predetermined distance from the picture display device, the strength of the dipole component is below a desired standard.

Abstract: Cathode ray tube apparatus including compensation (14) for the vertical component of terrestrial and of other ambient magnetic fields (15). The compensation is achieved by the generation of an opposing vertical magnetic field by energization of the degauss coil (11, 12) in the apparatus. Two embodiments are described: one applies a continuous direct current (21) after the degaussing operation and the other applies a direct current component coincident with the degaussing signal to permanently magnetize components of the apparatus. The magnitude and polarity of the compensation provided may be variable.

Abstract: In a magnetron for microwave oven, a high-voltage input terminal structure 30 is provided on a shield box 26 mounted on a magnetron unit 22. The high-voltage input terminal structure 30 has a cylindrical earth electrode 33, a cylindrical high potential inner electrode 32 and a central conductor 31a. The cylindrical earth electrode 33 is secured to the shield box 26 and the cylindrical high potential inner electrode 32 is coaxially arranged in the cylindrical earth electrode 33. The central conductor 31a is connected through an inductor 28 to a cathode lead 27 of the magnetron unit 22. An insulating resin 34b is filled in a gap between the cylindrical earth electrode 33 and the highpotential electrode 32 to form a capacitor section C. Cylindrical insulating sheaths 37, 38 are formed by the resin on the both sides of the capacitor section C. The capacitor section C and the cylindrical insulating sheaths, 37, 38 are integrally formed and continuously extended along a straight line.

Abstract: Apparatus for inactivating the source of microwaves for an electrodeless lamp to prevent accidental release of microwaves into the environment as a result of failure to assemble the lamp with a conductive mesh. An electrodeless lamp which is provided with a gas manifold for directing a stream of cooling gas against a lamp envelope is provided with a gas leak passageway which is blocked when the conductive mesh assembly is in place. A pressure switch in fluid communication with the gas manifold is activated and prevents operation of the microwave source when pressure is reduced as a result of gas leaking through the gas leak passageway.

Abstract: An electron beam apparatus is disclosed which comprises a cylindrical chamber, ion pump exhaust zones arranged in a substantially ring-like array, and an electron gun located on the center axis of the ring-like array, thereby minimizing the distance between the exhaust zone of an ion pump and the electron gun for generating an electron beam. Since the ion pump exhaust zones are located immediately next to the electron gun, it is therefore possible to achieve substantially the same vacuum level at the location of the electron gun as that at the ion pump per se.

Abstract: Picture display device having a display tube and a deflection unit (9) comprising a field deflection coil and a line deflection coil (11). In order to comply with a predetermined interference radiation standard, the picture display device is provided with a compensation coil system having a first set of compensation coils (18, 19) for generating a dipole compensation field and possibly a second set of compensation coils (18a, 19a) for generating a fourpole compensation field, the compensation coil system being preferably arranged in series with the line deflection coil 11 ) and being provided with electric means (R; R.sub.1 ; R.sub.2 ; R.sub.3 ; R.sub.4) to shift the phase of the current through at least a part of the compensation coil system with respect to the phase of the current through the line deflection coil.

Abstract: A deflection yoke apparatus comprises pairs of horizontal and vertical deflection coils. A coil separator is located between both coils. A deflection core forms a magnetic path for a magnetic flux generated from both deflection coils. An auxiliary coil is arranged at least a one position in a vertical deflection direction outside the deflection core. A horizontal deflection current is supplied to this auxiliary coil. A magnetic field, generated from the auxiliary coil, reduces an intensity of externally leaking magnetic field which radiates outside the deflection core when a horizontal deflection current is supplied to the horizontal deflection coils.

Abstract: A cathode ray tube (3) (CRT) has a deflecting coil (1) surrounded by a funnel-like casing (4) of magnetic material. The deflecting coil generates a magnetic deflecting field (B) for the electron beam and a magnetic leakage field (BL) in the CRT environment. The leakage field is composed of a dipole field and a quadrupole field. To reduce the magnetic field strength in the CRT environment a magnetic compensation field which is counterdirected to the leakage field is generated. The compensation field is composed of a dipole field which is generated by a first compensation loop (7) and a quadrupole field which is generated by a second compensation loop (9). The first compensation loop (7) is substantially flat and at right angles to the magnetic deflecting field (B). The second compensation loop (9) is flat and at right angles to the longitudinal symmetrical axis (z) of the CRT and has an upper (9a) and a lower (9b) part which generate two mutually opposing dipole fields (DK2,DK3).

Abstract: A cathode ray display tube has a magnetic shield comprising a mesh (60) of high permeability magnetic material such as mumetal covering the outer surface of its transparent faceplate (14) through which a display from a screen (16) is visible and which together with a magnetic shielding box (70) surrounding the remainder of the tube's envelope (10) inhibits extraneous magnetic fields entering the envelope and affecting the electron beam undesirably. The shielding arrangement is particularly useful with a flat tube having a relatively large area faceplate and using a low-energy scanning electron beam (32). The mesh (60) may be supported by one or more transparent members (66), and may be treated to enhance contrast of the display and also to act as a electromagnetic radiation shield.

Abstract: A magnetron comprises an anode cylinder, vanes extending radially and inwardly from the anode cylinder, an output-side-sealing metal cylinder sealed to the end of the anode cylinder, an antenna lead connected to one of said vanes and a plurality of flanged metal cylinders enclosing the antenna lead and disposed inside the output-side-sealing metal cylinder along the direction of a magnetron tube axis.

Abstract: The assembly has a low-pressure sodium discharge lamp (1), of which the outer envelope (4) has an electrically conducting coating (5), which is connected through a capacitor (29) to one of the current supply conductors (13) to the light source (3) of the lamp (1) and to the neutral conductor (18) of the power supply (2), which supplies an alternating voltage having a frequency of at least 80 kHz. The lamp holder (23) has an eccentrically arranged projection at its inner surface while the lamp cap (6) has an eccentrically arranged recess at its outer surface, which, when the lamp cap (6) is arranged in the lamp holder (23), engage with each other and guarantee a connection of the capacitor (29) to the neutral conductor (18). The lamp (1) is suitable for operation at mains voltage frequency and is still fitting into the lamp holder of mains voltage frequency equipment.

Abstract: Improved efficacy and color rendition at white color temperatures is achieved in an electrodeless metal halide arc discharge lamp with a novel combination of arc tube fill materials, including sodium halide, cerium halide, and xenon. A preferred lamp structural configuration imparts further efficacy improvement at higher lamp operating temperatures and isothermal lamp operation.

Abstract: An illumination apparatus includes a discharge tube for emitting light upon an application of an external high frequency wave electromagnetic field, an electrode, arranged outside the discharge tube, for applying the high frequency wave electromagnetic field to the discharge tube, a high frequency wave applying unit for supplying high frequency wave power to the electrode, and a projected portion extending from the discharge tube. The projected portion extends to a position where the high frequency wave electromagnetic field generated by the electrode has a level lower than a discharge initiation level. The high frequency wave power is controlled by changing a voltage, a frequency, a duty ratio or the like.

Abstract: Certain applications require a CRT display to be well shielded against emitting RF electromagnetic energy. A shield placed at the neck portion of a CRT envelope inhibits RF emissions from being transmitted through the face portion of the CRT. The shield comprises longitudinal conductors for suppressing transverse magnetic (TM.sub.01, TM.sub.02 . . . ) mode emissions and circular conductors for suppressing transverse electric (TE.sub.01, TE.sub.02 . . . ) mode emissions. Placing the shield at the rear of the CRT envelope eliminates the need for covering the face portion of the CRT with an optically transparent screen. To eliminate RF emissions from the CRT display the housing is provided with a contiguous RF emission shield that is connected to the shield on the neck of the CRT. Alternatively, an internal RF emission shield would enclose the video circuitry which includes all potential sources of undesired RF emission.

Abstract: A gas discharge apparatus includes a discharge chamber including a transparent dome portion and an electrode-including base portion, which together enclose an ionizable gas. A cup-shaped base member is affixed at its periphery to the edge of the base portion of the discharge chamber. A power supply and discharge excitation network is disposed within the interior of the base portion. The power supply and discharge network include a pair of terminals. An oscillator and associated step-up output transformer powered from the terminals is positioned between the terminals and the discharge chamber. A field shield including a conductive sheet member is positioned between the terminals and the discharge chamber. The field shield is adapted to be electrically coupled to the electrode so that discharge-supporting electric fields may be established in the discharge chamber between the electrode and through the dome portion of that chamber to an effective ground electrode exterior to the chamber.

Abstract: A magnetron with a filter case housing a through-type capacitor and a choke coil wherein a mounting plate for the capacitor is fixed in intimate contact with the wall of the filter case along a line encircling a through-hole drilled in the wall of the filter case for drawing out the terminals of the capacitor.

Abstract: A fluorescent lamp assembly having an electronic ballast circuit. A ballast circuit transformer is mounted on a metallic plate having a recess complementary to the transformer, and the metallic plate suppresses conducted RFI. A lamp cover is attached to the metallic plate and heat from the ballast circuit transformer is dissipated by the metallic plate and lamp cover.

Abstract: An electrodeless low-pressure discharge lamp comprising a glass lamp vessel sealed in a gas-tight manner and filled with a metal vapor and a rare gas, and a winding on a ferrite core. During lamp operation an electrical discharge is maintained in the lamp vessel by the winding connected to a high-frequency supply. The winding is surrounded by a thin-walled cylindrical metal body or layer which is electrically insulated from the winding, is interrupted at at least one area and is connected during operation of the lamp to one of the power mains conductors.

Abstract: A magnetron filter apparatus having a bottom box type filter case which is engaged and fixed with a cathode input side of a magnetron bulb and provided with a cover. A transformer which supplies a cathode current to the magnetron is contained in the filter case and a filter is contained in the filter case for preventing leakage of unwanted electromagnetic waves. Further, an insulation box in which the transformer is embedded and which is provided with integrally formed cylindrical portions through which lead wires to a primary winding of the transformer is disposed in the filter case. The insulation box is positioned by insertion of the cylindrical portions thereof into holes formed in a wall of the filter case.

Abstract: An electrodeless low-pressure discharge lamp having a lamp vessel (1), a core (3) of magnetic material, a first winding (7) arranged to surround the core and connected to a high-frequency supply unit (4), one of the lead-in wires of this winding being electrically connected to a lead-in wire of a second winding (11) with a free end (12), while during operation of the lamp the potential drop between the ends of the second winding is substantially equal to the potential drop between the ends of the first winding and the potential drops in the two windings vary in opposite senses. Interference currents at the supply mains to which the lamp is connected are then strongly suppressed.

Abstract: A microwave power source for a microwave oven in which a microwave magnetron is supplied simultaneously with filament heater power and with anode voltage through an inductive reactance power supply and has end shields with peripheral depressions to suppress end shield secondary emission oscillations during warm-up of the filament which can rapidly collapse to produce rapid shutoff of anode current and, consequently, undesirably high voltage spikes across the magnetron.

Abstract: An electrodeless metal vapor discharge lamp comprising a lamp vessel (1) which is sealed in a vacuum-tight manner and is further filled with a rare gas, which lamp is provided with a core (4) of magnetic material, in which a high-frequency magnetic field can be induced by means of an electric supply unit (7) and a winding (5) arranged to surround the core, an electric field being produced in the lamp vessel (1), the surface area of a cross-section orthogonal to the axis of the winding lying between 20 mm.sup.2 and 60 mm.sup.2, the lamp vessel (1) containing as rare gas krypton and/or argon at a pressure of at most 100 Pa, and the axial length of the winding lying between 8 and 15 mm.

Abstract: A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.