# Nonstationary oscillations in gyrotrons revisited

## Abstract

Development of gyrotrons requires careful understanding of different regimes of gyrotron oscillations. It is known that in the planes of the generalized gyrotron variables: cyclotron resonance mismatch and dimensionless current or cyclotron resonance mismatch and dimensionless interaction length complicated alternating sequences of regions of stationary, periodic, automodulation, and chaotic oscillations exist. In the past, these regions were investigated on the supposition that the transit time of electrons through the interaction space is much shorter than the cavity decay time. This assumption is valid for short and/or high diffraction quality resonators. However, in the case of long and/or low diffraction quality resonators, which are often utilized, this assumption is no longer valid. In such a case, a different mathematical formalism has to be used for studying nonstationary oscillations. One example of such a formalism is described in the present paper.

- Authors:

- Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, LV-1063 Riga (Latvia)
- Institute of Mathematics and Computer Science, University of Latvia, Raiņa bulv. 29, LV-1459 Riga (Latvia)

- Publication Date:

- OSTI Identifier:
- 22410340

- Resource Type:
- Journal Article

- Journal Name:
- Physics of Plasmas

- Additional Journal Information:
- Journal Volume: 22; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CAVITY RESONATORS; CYCLOTRON RESONANCE; DIFFRACTION; ELECTRONS; INTERACTIONS; MICROWAVE AMPLIFIERS; OSCILLATIONS

### Citation Formats

```
Dumbrajs, O., E-mail: olgerts.dumbrajs@lu.lv, and Kalis, H., E-mail: harijs.kalis@lu.lv.
```*Nonstationary oscillations in gyrotrons revisited*. United States: N. p., 2015.
Web. doi:10.1063/1.4921665.

```
Dumbrajs, O., E-mail: olgerts.dumbrajs@lu.lv, & Kalis, H., E-mail: harijs.kalis@lu.lv.
```*Nonstationary oscillations in gyrotrons revisited*. United States. doi:10.1063/1.4921665.

```
Dumbrajs, O., E-mail: olgerts.dumbrajs@lu.lv, and Kalis, H., E-mail: harijs.kalis@lu.lv. Fri .
"Nonstationary oscillations in gyrotrons revisited". United States. doi:10.1063/1.4921665.
```

```
@article{osti_22410340,
```

title = {Nonstationary oscillations in gyrotrons revisited},

author = {Dumbrajs, O., E-mail: olgerts.dumbrajs@lu.lv and Kalis, H., E-mail: harijs.kalis@lu.lv},

abstractNote = {Development of gyrotrons requires careful understanding of different regimes of gyrotron oscillations. It is known that in the planes of the generalized gyrotron variables: cyclotron resonance mismatch and dimensionless current or cyclotron resonance mismatch and dimensionless interaction length complicated alternating sequences of regions of stationary, periodic, automodulation, and chaotic oscillations exist. In the past, these regions were investigated on the supposition that the transit time of electrons through the interaction space is much shorter than the cavity decay time. This assumption is valid for short and/or high diffraction quality resonators. However, in the case of long and/or low diffraction quality resonators, which are often utilized, this assumption is no longer valid. In such a case, a different mathematical formalism has to be used for studying nonstationary oscillations. One example of such a formalism is described in the present paper.},

doi = {10.1063/1.4921665},

journal = {Physics of Plasmas},

issn = {1070-664X},

number = 5,

volume = 22,

place = {United States},

year = {2015},

month = {5}

}