Aminoamidines

Reactions ofN-aryl- andN-methyl-amidines and -amides of -amino acids with RPCl₂ afford 4-aryl(methyl)imino and 4-oxo-1,3,2-diazaphospholanes. 4-Phenylimino-1,3,2-diazaphosphorinane was obtained in a similar way by the interaction of N(1), N(2)-diphenyl--anilinoisobutyramidine with PhPCl₂.For communication 5 see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1116–1121, June, 1993.     

Some perspectives on the use of powerful gyrotrons for the electron-cyclotron plasma heating in large tokamaks

Conclusion The main problems for the further development of high efficiency powerful gyrotrons are obviously the elaboration of electron guns with a large current density and the ensuring of a stable single-mode operation in resonators with a large cross-section. For the increase in microwave pulse energy (with a pulse length of the order of the time of plasma confinement in large tokamaks) the investigation of the possibilities to diminish heating loads in the resonator and output window of a gyrotron is necessary.     

Design of a 3-MW 140-GHz gyrotron with a coaxial cavity

A design for a 3-MW 140-GHz gyrotron based on the use of a coaxial cavity is given. The cavity mode is TE_21,13, chosen so that the ohmic heating on both the inner and outer conductors would be low enough for CW operation. The mode selection process, nonlinear, multimode and time-dependent modeling of the beam wave interaction, and gun design are discussed in detail. An inverted magnetron injection gun (MIG) is used to accommodate the inner conductor. The radiation is coupled out via a quasi-optical mode converter, consisting of an irregular cylindrical waveguide section followed by a step-cut launching aperture and a single near-parabolic mirror. The design of these components is also described     

100-150 MW designs of two- and three-cavity gyroklystron amplifiersoperating at the fundamental and second harmonics in X- andKu-bands

Efficient 100-150 MW X- and Ku-band microwave sources with pulselengths of 1 μs are being developed for driving future linear colliders. Two- and three-cavity co-axial designs of relativistic gyroklystron amplifiers are presented here which fulfill these requirements. Numerical simulations predict over 40% efficiency, 45-50 dB gain, and 100-160 MW power level for the gyroklystron designs operating at fundamental (8.568 GHz) and second harmonic (17.136 GHz). It is shown that introducing a penultimate (buncher) cavity significantly improves efficiency and gain of the second-harmonic amplifier     

Electromagnetic properties of open and closed overmoded slow-waveresonators for interaction with relativistic electron beams

Specific slow wave structures are needed in order to produce coherent Cherenkov radiation in overmoded relativistic generators. The electromagnetic characteristics of such slow wave, resonant, finite length structures commonly used in relativistic backward wave oscillators have been studied both experimentally and theoretically. In experiments, perturbation techniques were used to study both the fundamental and higher order symmetric transverse magnetic (TM) modes. Finite length effects lead to end reflections and quantization of the wave number. The effects of end reflections in open slow wave structures were found from the spectral broadening of the discrete resonances of the different axial modes. The measured axial and radial field distributions are in excellent agreement with the results of a 2-D code developed for the calculation of the fields in these structures     

Competition of modes resonant with arbitrary cyclotron harmonics ina gyrotron with nonfixed axial structure of the high-frequencyfield

A general theory is developed for self-consistent calculations of mode competition in a gyrotron with nonfixed axial structure of the RF field for arbitrary cyclotron harmonics. The theory is applied to the gyrotron operating at the Kernforschungszentrum Karlsruhe with a frequency of 150 GHz. The formalism presented allows a self-consistent calculation of mode competition for the operating and parasitic modes at the cyclotron resonance at arbitrary harmonics. Specific calculations are carried out for the cases n₀=1, n₁ =2 and n₀=2, n₁=1. It is emphasized that the formalism considered applies only to the case in which the azimuthal orthogonality condition is satisfied: n₀m₁≠n₁ m₀. There are circumstances when this condition is not satisfied