| 摘要 |
1,096,921. Transit-time tubes. NATIONAL RESEARCH DEVELOPMENT CORPORATION. June 26, 1964 [March 28, 1963], No. 12348/63. Heading H1D. A choice for generating radiation in the millimetre/sub-millimetre region utilizes the interaction between a beam having a helical path under the action of a very high longitudinal magnetic field and wave modes set up in a microwave cavity. An electron beam E is projected from an obliquely disposed gun 4, 7 and is given a helical path by the high magnetic field, e.g. 2000 gauss, produced by a first solenoid 2. The beam passes into a microwave cavity formed by a coating of silver 12 on the shoulder and narrow part of the envelope 1 and enters a region of very high magnetic field, e.g. 100,000 gauss, produced by a second solenoid 11 either disposed within the first solenoid as shown, or the first solenoid may extend only over the wide part of the envelope. The radiation produced by the cyclotron motion of the electrons of the beam is obtained as a beam issuing from a quartz window 10. The beam and the second magnetic field are preferably pulsed, and the second solenoid preferably maintained in a super-conducting state by being placed in a cryostat. |
