Publication de 12 numéros par an
ISSN Imprimer: 0040-2508
ISSN En ligne: 1943-6009
Indexed in
ELECTRON BUNCHING IN THE KLYNOTRON-TYPE OSCILLATORS. KLYNOTRON AS A FREQUENCY MULTIPLIER
RÉSUMÉ
The easy-to-use and cost-efficient oscillators suitable for the submillimeter waveband and especially in its short-wave part are still a challenge to be solved. Though providing satisfactory results in the long-wave part of the submillimeter waveband, backward wave tubes (BWTs) are as good as inapplicable in its short-wave part. Available engineering methods are not capable of providing extremely thin high-current-density electron beams required for this waveband. Frequency multipliers are able to considerably mitigate such strict requirements to the electron beams. A klynotron-type oscillator can be used for electron beam bunching in the frequency multiplier. In the klynotron oscillator, a wide and comparatively thick sheet electron beam is directed at a small angle to the surface of the slow-wave structure and is partly dissipated on this surface. The output power provided by the klynotron exceeds that of a conventional BWT by several orders. This is a crucial condition for obtaining good (i.e., deep) bunching of an electron beam. Our goal is to investigate the process of dense electron bunching in klynotron-type oscillators and to clarify the conditions of its use for electron beam bunching in a frequency multiplier. In this paper, we analysed the electron bunching in the klynotron numerically, using our proprietary software, specially designed to take into account all specific features of the klynotron operating mode. Three-dimensional motion of electron was investigated in the finite focusing magnetic field. The numeral simulations revealed the effect of "layer-by-layer" bunching of the electron beam in a klynotron-type oscillator. The farther an electron layer is located from the surface of the slow-wave structure, the later electron bunching in that layer occurs. It was shown that by selecting the proper operation mode and the slope angle between of the focusing magnetic field and the comb surface one can obtain dense electron bunches in the part of the beam outside the klynotron slow-wave structure, where the second slow-wave structure should be located functioning as a power take-off. This can be considered as a proof that klynotrons can be used in the frequency multiplier engineering.