Abstract: The magnet roll of the present invention includes a shaft and a permanent magnet member fixed to the shaft, the permanent magnet member being composed of a hollow, cylindrical magnet body, and a magnetic pole piece fixed to a recess of the hollow, cylindrical magnet body, the hollow, cylindrical magnet body having a plurality of axially extending magnetic poles arranged circumferentially on the surface, the magnetic pole piece being provided with two magnetic poles having the same polarity for constituting a developing magnetic pole, and a thermally demagnetized portion being formed substantially at a center of the developing magnetic pole such that the permanent magnet member generates a magnetic flux density distribution having two peaks of the same polarity at a position of the developing magnetic pole.

Abstract: A deactivator for use in an electronic article surveillance system has a housing having a first receptacle containing a deactivator for deactivating a theft-deterrent marker carried on an object such as a compact disk case, an audio cassette case or a video cassette case. The first receptacle is made up of a base, a first wall and a second wall, the walls being spaced apart such that an object carrying the theft-deterrent marker can be placed between the walls. The first wall is slidable relative to the second wall. The housing also has a second receptacle with a deactivator for deactivating a theft-deterrent marker carried on a generally rectangular object such as an audio cassette box having a top and a bottom, first and second sides and first and second ends, the marker being carried by one of the sides or one of the ends. The device comprises a housing having a receptacle comprising first, second and third walls arranged so as to form three sides of a box.

Abstract: A premagnetizing head for charging the magnetizable pigment of characters printed on a document includes a permanent magnet (10) whose one pole is connected to a magnetically conductive metal plate (12) which extends away from the magnet (10) in a direction generally transversal to the north-south pole axis of the magnet and up to the document (D) whose characters are to be magnetized and read. The permanent magnet (10) is oriented so that its northpole-southpole axis will extend generally parallel with the plane of the document (D) to be read.

Abstract: An alternating current generator for vehicle has a permanent magnet in the rotary field core unit. Providing such magnet is effective to reduce leakage magnetic flux and the size of the machine. In order to magnetize the magnet without trouble caused by machined chips or iron powder, the magnet is magnetized after the rotary field core has been machined. While the magnet is magnetized in a short period by a pulse current, the field coil is short-circuited. The field coil is subjected to magnetizing flux passing therethrough and generates short-circuit current and, consequently, counter magnetomotive force, which prevents leakage of the magnetizing flux.

Abstract: A deactivating device for magnetic markers in an electronic article surveillance (EAS) system includes a housing adapted to constrain typical audio and video cassettes in preferable orientations with respect to first and second deactivating surfaces. The first deactivating surface includes a first magnetic insert, which includes a first magnet designed to produce a deactivating magnetic field which deactivates markers affixed to audio and/or video cassettes without causing audible signal degradation of the prerecorded magnetic media within the audio or video cassette. The second deactivating surface includes a second magnetic insert and second magnet designed to produce a deactivating magnetic field which deactivates markers placed in the recessed edge of video cassette without causing audible signal degradation of the prerecorded magnetic media contained in the video cassette. An alternate magnetic insert which can be substituted for the first and second magnetic inserts is also described.

Abstract: A process and apparatus for permitting the magnetization of flexible hard magnetic materials in the form of sheets or strips, such as magnetic rubber, wherein opposing arrays formed from alternating magnetic disks and flux conducting elements are use in sets of two with opposing polar moments such as to induce a magnetic flux in the gap between the discs. The width of the magnetic disk and flux conducting elements, respectively, are selected to optimize the magnetic pull strength of the material. At the array ends are flux conducting elements that are about 1/2 (i.e., from about 0.25 to about 0.75, and preferably from about 0.4 to 0.6) of the width of the internal flux conducting elements. A material to be magnetized is passed between the array sets in contrast with both disks and consequently imprinted with magnetic poles. The magnetized properties of the material is enhanced by passing the material through a second set of arrays which are axially offset with respect to the first set of arrays.

Abstract: Disclosed is an apparatus and process for magnetizing permanently magnetizable strip and sheet material to form a pattern of band-like poles on the material. Two parallel stacks of permanent magnets are used, each magnet in each stack having a direction of magnetization which is perpendicular to a slot-like air gap between the stacks. The magnets in each stack are parallel to one another, with unlike poles of adjoining magnets proximate so that they mutually attract one another. Unlike poles of the respective magnets in opposite stacks are positioned diametrically opposite each other across the air gap. The apparatus does not use electromagnetic coils and can form very narrow, contiguous band-like poles on magnetizable sheet or strip material which is passed through the air gap.

Abstract: A positioning current is supplied to each phase winding of a stator employed in an electric motor, thereby rotating a rotator in the motor to a predetermined reference position with the use of magnetic force created by the positioning current. Thereafter, a polarizing current is supplied to each phase winding of the stator, thereby polarizing permanent magnets incorporated in the rotator.

Abstract: A lateral orientation type of anisotropic permanent magnet having a face of magnetic application and at least one lateral face adjacent to the face of magnetic application. An axis of easy magnetization of particles of a magnetic powder constituting the permanent magnet is oriented substantially along lines from the lateral face toward the face of magnetic application to increase the peak value of the surface magnetic flux density at the face of magnetic application.

Abstract: A magnet is fixed to the inner surface of the ceiling of a cylinder-like yoke which is closed at the top, and a holding plate is attached to the yoke through a slider. A coil and collet are unitedly attached to the holding plate. When a current is passed through the coil, a force proportional to the current acts on the coil so that a constant load is applied to the collet.

Abstract: A security system includes a magnet having a high magnetic field strength and wide flux area. Individuals seeking to enter or leave a secure area are directed so as to be in relatively close physical proximity to the magnet. Hard or soft ferrous material on the individual, which would be included in any items likely to be pilfered, are magnetized sufficient to generate a signal to a magnetometer, to which the individuals are proximately directed after passing the magnet. Detection of a magnetized, ferrous substance in the magnetometer causes the locking of a turnstile, forcing the individual to a secondary area. A magnetic card, unique to an individual, can also be utilized to facilitate identification of an individual prior to entry to the system, as well as to catalogue security breaches and ingress/egress times.

Abstract: A deactivator for magnetically altering a tag used in an electromagnetic article surveillance system. The deactivator is adapted for use in conventional, pre-existing check-out counters. An elongated cover plate is secured on top of a transition plate which spans the distance between a check-out counter conveyor belt and countertop. An elongated magnet assembly is positioned between the cover plate and the transition plate. The magnet assembly provides a magnetic field above the cover plate that is capable of deactivating a magnetically alterable tag secured to an object to be purchased as the object is passed over the cover plate from the conveyor belt to the countertop.

Abstract: Described are magnetizing devices for permanent magnet rings that are bipolar on the end faces or multipolar on the lateral faces and have concentric North/South areas either on one of the two end faces or on their lateral faces. Magnetizing is performed by way of current pulses that are induced in annular current conductors arranged on the end faces or on the lateral faces of the permanent magnet rings.

Abstract: A deactivating device for deactivating a dual status EAS tag for use in an EAS system in which the device utilizes a detection field for detecting the presence of an active tag in a detection/deactivation zone and in which the device further utilizes a deactivation field which is matched to the detection field.

Abstract: A magnetizing apparatus capable of magnetizing a magnetic roller having a length up to 30 cm is provided. The magnetizing apparatus is comprised of at least two split members, each of which is provided with magnetic heads employed for applying magnetic fields to a magnetic roller. The end face of each magnetic head is shaped in agreement with the profile of the magnetic roller so that there would be no air gap formed between the magnetic head and the magnetic roller when they come into contact with each other. The split members are separated first and then combined to accommodate the magnetic roller within the magnetizing apparatus. After magnetization, a magnetic force is induced between the magnetic head and the magnetic roller such that an external force stronger than the magnetic force is used to pull the split members apart to fetch out the magnetic roller.

Abstract: A method of trapping a field in a block of superconductor material, includes providing (i) a block of material defining a bore, (ii) a high permeability core within the bore that defines a low reluctance path through the bore, (iii) a high permeability external structure on the exterior of the block of material that defines a low reluctance path between opposite ends of the core, and (iv) an electromagnet configured to apply a magnetic field around the high permeability core. The method proceeds by energizing the electromagnet to produce an applied magnetic field around the high permeability core, cooling the block of material sufficiently to render the block of material superconducting, de-energizing the electromagnet to result in a trapped magnetic field, and at least partially removing the low reluctance path defined by the core and the external structure in order to increase the magnetic flux density of the trapped magnetic field.

Abstract: In a deflection yoke mounted on a cathode ray tube, a pair of silicon steel field harmonic enhancers are placed over rear portions of a horizontal deflection coil of a saddle coil type near an electron beam entrance region of the coils such that portions of the saddle coils are interposed between the field harmonic enhancers and a neck portion of the cathode ray tube. The field harmonic enhancers reduce horizontal coma error by making the horizontal deflection field in the rear portion of the saddle coils more pincushion shaped.

Abstract: A desensitizing apparatus for magnetizing a desensitizable marker used with an electromagnetic article surveillance system. The apparatus includes a rectangular, non-metallic plate positioned so that its length is perpendicular to a likely direction of travel of the marker to be magnetized. A row of X-shaped arrays of elongated magnets is embedded on the plate. A marker passing over the row of magnets will be desensitized regardless of its orientation or direction of travel over the magnets.

Abstract: An apparatus for erasing information recorded on a magnetic tape wound into a roll having a diameter. The apparatus comprises an erasing coil wound in the form of a solenoid defining a space therein. The space has a width shorter than the diameter of the magnetic tape roll and a length longer than the diameter of the magnetic tape roll. The magnetic tape roll is moved intermittently to different erasing positions in a predetermined sequence so that the magnetic tape roll has different portions placed in the space at the respective erasing positions. A ringing signal is applied to the erasing coil to provide a magnetic field in the space for erasing information recorded on the magnetic tape roll each time the magnetic tape roll is placed at one of the erasing positions.

Abstract: Apparatus for selectively magnetizing and demagnetizing a small tool, such as a screwdriver, by providing an enclosure having a first opening to receive a tool for magnetizing a desired portion of the tool, and a second opening to receive a tool for demagnetizing a selected portion of the tool. The demagnetizing opening is surrounded by a demagnetizing coil that is directly connected through a first switch with a source of alternating current to provide an alternating magnetic field for demagnetizing a tool inserted into the demagnetizing opening. The magnetizing opening is surrounded by a magnetizing coil that is connected through a second switch with the source of alternating current and through a rectifier circuit to provide a continuous magnetic field for magnetizing a tool inserted into the magnetizing opening. Pilot lights are coupled with the respective magnetizing and demagnetizing loops to indicate when the respective loops are energized.

Abstract: Magnetically desensitized targets or sensor elements on protected articles are resensitized by means of rotating permanent magnets which are moved relative to the magnetized target desensitizer elements such that the elements become subjected to reversing magnetic fields of gradually decreasing intensity.

Abstract: Disclosed is a permanent magnet which is suitable for use for a field system of an electric motor or the like and which is constituted by a single piece of magnetic material in which S and N poles are alternately continuously formed through non-magnetic flux regions or weak magnetic flux regions interposed therebetween, and further disclosed is a magnetization apparatus for magnetizing such a permanent magnet.

Abstract: A hand scanner intended for optically reading a bar code on an item of goods and therewith produce an electric signal which corresponds to the read bar code. The invention is characterized in that the hand scanner (1) is provided with one or more permanent magnets (3, 4) in the vicinity of its optical bar-code reading device.

Abstract: A multiple magnet assembly for magnetizing a magnetizable element of a desensitizable electromagnetic article surveillance marker, in which each successive assembly provides at a working surface a magnetic field of the same polarity but decreasing intensity. Any demagnetization effect attributable to reverse or back fields associated with one assembly are overcome by magnetization produced by a subsequent assembly, thus allowing markers having magnetizable elements with significantly different coercivee forces to be magnetized by the same apparatus.

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: An apparatus for use with magnetically based electronic article surveillance systems employing certain types of markers includes a hollow core having a gap in its perimeter, a coil of wire wrapped around a portion of the core, and appropriate circuitry to drive the combination as an electromagnet. The gap configuration produces an external field of large intensity but limited range, such that the magnetizable portion of a marker is magnetized without affecting magnetic states of the article to which the marker is affixed. Depending on the nature of the circuit, the apparatus may be used as a desensitizer of such markers, or preferably as a resensitizer. The resensitizer incorporates a proportional-integral controller that keeps the level of the alternating current constant.

Abstract: The device comprises a demagnetization coil (1) wound from electrically conducting insulated wire (5) and surrounded by an electrically insulating sheath (7). A connection member (17) is connected to the two ends of the wire (5). The connections (19) between the connection member (17) and the wire (5) are surrounded by an electrically insulating envelope constituted by a sheet (21) of electrically insulating foil, which is folded so that the connections (19) and the adjoining parts of the sheath (7) are disposed between the facing parts of the sheet (21). The edges of the sheet (21) conducting each other are connected to each other by means of a welding connection (23). The sheet is further connected by means of a welding connection (23) to the sheath (7) and to an envelope of the connection member (17). The sheet 21 constitutes an envelope for the connections (19), which is tight but for one lead-through opening for the connection member (17).

Abstract: A high resolution sensor for internal combustion engines has symmetric and asymmetric magnetic encoders mounted on a support plate for synchronous rotation with the engine. Hall-effect sensor devices monitor the magnetic fields of the encoders and transmit signals to an Electronic Engine Control Unit. Ignition and fuel injection timing are deduced from the positions of the magnetic encoders. The encoders are magnetized on a fixture which establishes the size, strength, and location of each pole.

Abstract: A fixture for multi-pole magnetization of a magnetizable part has two carrier plates, each having a serpentine channel therein, with an electrical conductor contained in each channel. The electrical conductors each have a thin portion having a cross section which is less than the cross section of the remainder of the conductor. The thin portions of the conductors are mounted so as to be movable in the channels. A part to be magnetized is arranged between the thin portions of the conductors, and the conductors are supplied with a current surge. As a result of the flexibility, and the movable mounting, of the conductor portions, they are caused by the power surge to move against the magnetizable part, thereby creating differently magnetized, adjacent regions in the part, having a boundary therebetween coinciding with the location of the thin portions. A magnet is thereby achieved which is substantially the same as joined individual magnets of opposite polarity.

Abstract: An apparatus for magnetizing a permanent magnet which includes a frame including first and second relatively movable members arranged to form a core frame which supports first and second conic co-axial poles enclosed by the movable frame members for creating a magnetic flux circuit with an adjustable air gap for enclosing a product to be magnetized. The apparatus is energized by coils wound about the poles and enclosing the air gap. The poles include a bore co-axially aligned with the co-axial axis of the poles and a press ram dimensioned to move within the bore.

Abstract: An external magnetizing method and external magnetizing apparatus for a rotary electric apparatus having internal permanent magnets, which obtains permanent magnetization of metal pieces fixed along the internal circumference of a yoke from the outside of the yoke while the rotor is situated within the yoke. The external magnetizing method includes the steps of creating the permanent magnets by applying a voltage from a capacitor power source to a yoke magnetizing device adjacent the external circumference of the motor yoke, then incrementally rotating the rotor in its normal rotating direction and thereafter reapplying the capacitor power source voltage to the yoke magnetizing means to again magnetize the metal pieces to obtain a more uniform magnetization when using a capacitor power supply .

Abstract: A magnetic field sensing and canceling circuit for use with a cathode ray tube (CRT) has a closed loop system consisting of flux gate sensors to measure external magnetic fields and magnetic field cancellation coils around the perimeter of the faceplate of the CRT to cancel the fields and thus minimize color and positional ac image distortion. The coils are mounted on an enclosure fabricated of a high permeability material and are positioned around the perimeter of the CRT's faceplate. Four of the coils are parallel to the top, bottom, and sides of the enclosure opening and a fifth coil is wound around the enclosure adjacent the CRT faceplate. The magnetic flux gate sensors provide output signals that are functions of the detected fields. These signals control the current in the magetic field cancellation coils and thus control the cancellation fields.

Abstract: A method and apparatus for producing complex magnetization patterns in a sheet of magnetic material. A fixture having top and bottom plates with a matching conductor pattern embedded in one surface of each plate. The conductor pattern covers substantially the entire surface of each plate. To magnetize the sheet of magnetic material, it is placed between the plates and a magnetizing current is applied to the conductors with a capacitor discharge magnetizer. The resulting sheet of magnetized material is useful as a magnetic deactivator for electromagnetic security articles.

Abstract: A compact, portable magnetization/demagnetization device comprises a tubular housing internally of which at one end is mounted an electrical coil which surrounds a cavity accessible to screwdrivers and the like. At the opposite end of the housing there is mounted a pair of AC prongs. A manually operated switch on the housing permits the coil to be energized when the prongs are energized to establish a magnetic field in the cavity for the purpose of magnetizing and demagnetizing tools and other objects.

Abstract: An apparatus for producing a uniform magnetic field in a test sample having an angled end during a magnetic particle test procedure, includes a conductive, angled fixture having a contact surface and an overall shape corresponding to that of the angled end of the test sample, so that when a pulsed current is passed through the blade, the resulting uniform magnetic field permits detection of defect indications in the angled end.

Abstract: A method of improving the magnetic properties of a ferromagnetic materials is disclosed. The method comprises a step of providing a specimen made of Fe, Ni or Co based amorphous alloys in a magnetizing field and a second step of applying an AC current or pulsed current on the specimen to improve its soft magnetic properties. The applied AC current has a frequency of 50 to 50K Hz, a wave form of either sine wave, triangular wave or square wave, and a current density of 10 to 500 A/cm.sup.2. The magnetic properties of the ferromagnetic materials are improved by a coercivity ratio less than 0.5, a magnetic induction ratio greater than 1 and a core loss ratio less than 0.3.

Abstract: The apparatus is used to make a magnet with a plurality of magnetic pole pairs. One or more pole pairs is formed by the apparatus as an initial step. Thereafter, additional pole pairs are formed by moving the apparatus with respect to the body to be magnetized or moving the body to be magnetized with respect to the apparatus. The apparatus is constructed so that previously magnetized portions of the magnetizable body are not demagnetized or significantly altered by the magnetization of adjacent parts of the magnetizable body.

Abstract: The magnet roll according to the present invention comprises (a) first and second shafts rotatable around the same axis relative to each other; (b) a permanent magnet member fixed around the second shaft and having a plurality of magnetic poles extending along the axis of the second shaft on its outer surface; (c) a first flange member connected to the first shaft and rotatably supporting one end of the second shaft; (d) a second flange member rotatably supported by the second shaft; (e) a hollow cylindrical sleeve made of a plastically deformable non-magnetic material and fixed to the first and second flange members on both ends such that it encircles the permanent magnet member rotatably relative to the permanent magnet member; and (f) an inner diameter-increased area provided in each side end portion of the sleeve, which receives each flange member and is folded inward over each flange member to fix the sleeve to each flange member.

Abstract: A method of deactivating a frequency-dividing-transponder that includes an active strip of magnetic material that, when magnetically biased to be within a predetermined magnetic field intensity range, responds to excitation by electromagnetic radiation of a first predetermined frequency by radiating electromagnetic radiation of a second predetermined frequency that is a frequency-divided quotient of the first predetermined frequency; and a magnetized bias strip of magnetic material having first and second ends and disposed in relation to the active strip of magnetic material for magnetically biasing the active strip of magnetic material to be within the predetermined magnetic field intensity range only when the bias strip of magnetic material is magnetized includes the step of converting the bias strip of magnetic material into a tripole bar magnet, having a pole of one magnetic polarity in a predetermined region of the strip located between the ends of the strip, and having a pole of a different magnetic pol

Abstract: This specification discloses a method of manufacturing a magnet roller having the step of disposing a plurality of pairs of magnetic poles each comprising the starting magnetic pole and terminal magnetic pole of a magnetic line of force on the peripheral surface of a cavity in a metal mold in which a resin magnet is molded and oriented so that straight lines passing through the starting magnetic poles and terminal magnetic poles of the pairs of magnetic poles are substantially on the same plane and extend through the cavity substantially in parallelism to one another, molding and orienting a resin magnet material poured into the cavity while applying a plurality of magnetic lines of force for orientation into the cavity in the same direction, thereby obtaining a molded article having at least four magnetic peaks, and the step of inverting part of the magnetic properties of the magnetic peaks of the molded article so that the magnetic properties of the adjacent magnetic peaks differ from each other.

Abstract: A flux scanner head generates a unidirectional magnetic field external to the head adjacent a scanning surface thereof. Workpieces to be subjected to magnetic particle inspection may be successively passed through, held in, or otherwise associated with, the unidirectional field at different angles to achieve magnetization along multiple axes, without physical or electrical contact with the workpiece. The scanner head is usable with both residual and continuous methods of magnetic particle inspection, and as either a hand-held or fixed-mount system. The scanner head itself incorporates a coil having a plurality of turns with a ferromagnetic core separating such turns so as to intensify and direct outward and external to the surface of the scanner head the magnetic field generated by current flow through the coil.

Abstract: Superconducting persistent current rings are mass produced by passing each uperconducting ring through a tapered magnetic field that is tapered in strength so that when each ring passes through the maximum magnetic field of the tapered magnetic field which is above the critical field of the tapered magnetic field the superconducting ring becomes normal thereby admitting all of the flux to which its cross section is exposed. When the ring is passed to a region of field lower in strength than the critical field, the ring becomes superconducting again and traps the flux to which its cross section is exposed.

Abstract: A method of magnetizing high energy rare earth alloy magnets by applying a magnetic field while heating the magnetic alloy.

Abstract: A specially designed magnetic circuit which is provided which is intended to magnetize cylindrically shaped magnetic materials (1) in the axial direction. The magnetic circuit comprises a magnetizing coil (2), permanent magnets (5, 6), and magnetic return conductors (3, 7) of a ferromagnetic material. The magnetic circuit is well suited to utilize the magnetostrictive properties of a magnetic material.

Abstract: A ferromagnet material having a high permeability and saturation magnetizon at low temperatures is used to induce superconducting currents in a ring of a superconducting material where the ferromagnet material has a lower transition temperature than the superconductive material.

Abstract: A device for magnetographic quality inspection of a material, whereby a magnetic-recording medium is applied onto the material to be inspected, and they are together magnetized so that the resulting magnetogram can be used to assess the quality of the material. According to the invention, the intensity of the magnetizing field is established by the maximum curvature of the surface of a drop of a magnetic fluid applied onto the surface of the material to be inspected. A magnetic substance is placed between the magnetic-recording medium and the material so that the surface of the latter is smoothed out. The magnetizing device includes a magnetic yoke and a magnetizing coil loosely fitted thereon and composed of sections which are connected in parallel to one another.

Abstract: A permanent magnet type demagnetizing head has a first magnetic part disposed on a front part(21a.sup.1, 21a.sup.2, 21a.sup.3) of a tape running surface of a magnetic material, a second magnetic part (21c) disposed on a rear part of the tape running surface and a non-magnetic part or a feeble magnetic part (21b) disposed between the first and the second magnetic parts in the tape running direction; and the first magnetic part is magnetized in a magnetic pattern having plural magnetized regions of one or more N-pole and S-pole; the second magnetic part is magnetized in a magnetic pattern of alternating stripes of N-pole regions and S-pole regions, the boundaries between neighboring N-pole regions and S-pole regions are inclined, and the intensity of magnetization are gradually reduced in the tape running direction.

Abstract: A magnetizer for magnetographic inspection of articles comprises a main electromagnet, an auxiliary electromagnet, and a power supply unit for the windings of the electromagnets. The auxiliary electromagnet is offset with respect to the central zone of the magnetic field established by the main electromagnet, in a direction perpendicular to that of the magnetic lines of force of the main electromagnet, and is mounted for changing its position.

Abstract: A method of manufacturing a color display tube having a magnetic quadrupole post-focusing mask, in which the mask is magnetized by magnetic field shaping means of soft iron, or the magnetic equivalent, having raised portions, for example strips placed against opposite sides of the mask sheet and subjected to an external strong magnetic field by an electromagnet to induce magnetic poles through the thickness of the mask sheet. The geometric arrangement of the raised portions of the field shaping means is such that cyclically a north pole, a south pole, a north pole and a south pole are induced into the sheet material surrounding each aperture. Using this technique, the entire area of a mask sheet can be magnetized in one operation. Also masks for small tubes and high definition tubes can be made.

Abstract: Micropole undulators for use in the generation of x-rays from moving charged particles and methods for manufacturing such undulators are disclosed.One type of micropole undulator has two jaws containing rows of spaced apart poles arranged so that each pole produces a magnetic field aligned with all other similar fields. An external biasing field extends through the jaws so that an overall undulator field of substantially sinusoidal shape and substantially zero average value extends along the undulator axis. Preferably, the poles are bars formed of a magnetizable, but unmagnetized, material so that, after the jaws are assembled, all of the bars can be magnetized simultaneously in a uniform magnetic field of suitable strength.