1. A process for producing a rare earth magnet, the process comprising:
an adhesion step of causing a diffusion element capable of diffusing inwardly to adhere to a surface part of a magnet material comprising a compact or sintered body of rare earth alloy particles; and
an evaporation step of heating the magnet material in vacuum to evaporate at least a portion of the diffusion element having been retained on or in the surface part of the magnet material, wherein:
the adhesion step is a vapor deposition step that causes heated magnet material and heated diffusion material including the diffusion element to come close to each other in vacuum and exposes the magnet material to a vapor of the diffusion element evaporated from the diffusion material thereby to vapor deposit the diffusion element on the surface of the magnet material;
the evaporation step is a step that, subsequently to the vapor deposition step, heats the magnet material in vacuum without cooling the magnet material to room temperature region; and
the adhesion step and the evaporation step are repeated in this order.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of operating a gas-discharge laser for providing laser output in the form of laser output pulses, the laser including spaced-apart gas-discharge electrodes powered by a radio frequency power supply (RFPS), with a laser-resonator formed between the discharge electrodes, the method comprising:
delivering a first train of RF pulses from the RFPS to the gas-discharge electrodes for energizing the laser-resonator, each pulse in the train including a plurality of cycles of RF energy, the RF pulses in the first train of RF pulses being temporally spaced apart by a time sufficiently short that the laser-resonator responds to the first train of RF pulses as though the first train of RF pulses were a single RF pulse, whereby the laser-resonator delivers a first laser-output pulse in response to the energizing by the first train of RF pulses.
2. The method of claim 1, wherein the first train of RF pulses includes an initial pulse having a first duration followed by a plurality of pulses having a second duration shorter than the first duration.
3. The method of claim 1 wherein all of the RF pulses in the first train thereof have the same duration.
4. The method of claim 1, further including, following delivery of the first train of RF pulses, delivering a second train of RF pulses from the RFPS to the gas-discharge electrodes for energizing the laser-resonator, each pulse in the second train including a plurality of cycles of RF energy, the RF pulses in the second train of RF pulses being temporally spaced apart by a time sufficiently short that the laser-resonator responds to the second train of RF pulses as though the second train of RF pulses were a single RF pulse, whereby, following delivery of the first single laser output pulse, the laser-resonator delivers a second laser-output pulse in response to the energizing by the second train of RF pulses, and wherein one of the duration and number of RF pulses in the second train thereof is selected such that the first and second laser output pulses have about equal power.
5. The method of claim 4, wherein the first and second trains of RF pulses have about the same duration.
6. The method of claim 5, wherein the first and second trains of RF pulses have the same number of pulses therein.
7. The method of claim 6, wherein the RF pulses in the first train thereon have a first duration and the RF pulses in the second train thereof have a second duration, with the second duration being longer than the first duration.
8. The method of claim 6, wherein the first train of RF pulses includes an initial pulse having a first duration, followed by a plurality of pulses each having a second duration, and second train of RF pulses includes an initial pulse having a third duration, followed by a plurality of pulses each having a fourth duration, and wherein the third duration is longer than the first duration, and the fourth duration is longer than the second duration.
9. The method of claim 5, wherein the duration of RF pulses in the first and second trains thereof is the same and the number of pulses in the second train thereof is greater than the number of pulses in the first train thereof.
10. The method of claim 4, wherein the selection of the number or duration of RF pulses in the second train thereof is dependent on a time between a termination of the first laser output pulse and an initiation of the second laser output pulse.
11. Gas-discharge laser apparatus comprising:
spaced-apart discharge-electrodes;
a laser resonator extending between the discharge electrodes;
a radio-frequency power-supply (RFPS) connected to the discharge electrodes for energizing the laser resonator;
an electronic circuit connected to the RFPS, the electronic circuit configured and arranged to receive a first command pulse, convert the command pulse to a first train of command pulses, and deliver the first train of command pulses to the RFPS, thereby causing the RFPS to deliver a corresponding first train of RF excitation pulses to the laser resonator with the temporal spacing between the RF excitation pulses being sufficiently short that the laser resonator responds to the first train of excitation-pulses as though the first train of excitation-pulses were a single RF excitation pulse, whereby the laser-resonator delivers a first single, laser-output pulse in response to the energizing by the first train of RF excitation pulses.
12. The apparatus of claim 11 wherein the electronic circuit is further configured and arranged, following receipt of the first command pulse, to receive a second command pulse, determine a time between termination of the first command pulse and initiation of the second command pulse, convert the second command pulse to a second train of command pulses, and deliver the second train of command pulses to the RFPS, thereby causing the RFPS to deliver a corresponding second train of RF excitation pulses to the laser resonator with the temporal spacing between the RF excitation pulses being sufficiently short that the laser resonator responds to the second train of excitation-pulses as though the second train of excitation-pulses were a single RF excitation pulse, whereby the laser-resonator delivers a second single, laser-output pulse in response to the energizing by the second train of RF excitation pulses, and wherein one of the number and duration of pulses in the second train of command pulses, and correspondingly in the second train of RF excitation pulses, is selected, based on the determined time between termination of the first command pulse and initiation of the second command pulse, such that the first and second laser output pulses have about equal power.
13. A method of operating a gas laser, said laser including electrodes connected to a radio frequency (RF) power supply for exciting a gas between the electrodes, said method comprising the steps of:
generating a command to produce a first laser pulse;
in response to the command to produce a first laser pulse, delivering a first envelope of RF power to the electrodes, the first envelope including a first train of pulses, each pulse in the train including a plurality of cycles of RF energy;
generating a command to produce a second laser pulse; and
in response to the command to produce a second laser pulse, delivering a second envelope of RF power to the electrodes, with the first and second envelopes having about the same duration, the second envelope including a second train of pulses, each pulse in the train including a plurality of cycles of RF energy, and wherein if the time between the end of the first laser pulse and the start of the second command to produce the second laser pulse is shorter than a predetermined period, then increasing the duty cycle of the pulses in the second pulse train so that the energy in the second laser pulse more closely matches the energy in the first laser pulse.
14. A method as recited in claim 13 wherein the duty cycle in the second pulse train is increased by an amount inversely proportional to the time between the end of the first laser pulse and the generation of the second command to produce the second laser pulse.
15. A method as recited in claim 13 wherein said predetermined period corresponds to the shortest time wherein the second laser pulse would still have about the same energy as the first laser pulse if the duty cycle of the first and second pulse trains remained unchanged.
16. A method as recited in claim 13 wherein the duty cycle of the second pulse train is increased by increasing the number of pulses in the second pulse train.
17. A method as recited in claim 13 wherein the duty cycle of the second pulse train is increased by increasing the length of the pulses in the second pulse train.
18. A method as recited in claim 13 wherein the first pulse in each train of pulses is longer than the remainder of the pulses in the train.
19. A method as recited in claim 13 wherein the laser pulses are used to drill holes in a workpiece.
20. A method as recited in claim 13 wherein the laser pulses are used to drill a via hole in a printed circuit board.