Nonlinear structures of lower-hybrid waves driven by the ion beam
Bibliographic record
Abstract
The lower-hybrid waves can be driven unstable by the transverse ion beam in a partially magnetized plasma of a finite length. This instability mechanism, which relies on the presence of fixed potential boundary conditions, is of particular relevance to axially propagating modes in a Hall effect thruster. The linear and nonlinear regimes of this instability are studied here with numerical simulations. In the linear regime, our results agree with analytical and numerical eigenvalue analysis conducted by Kapulkin and Behar [IEEE Trans. Plasma Sci. 43, 64 (2015)]. It is shown that in nonlinear regimes, the mode saturation results in coherent nonlinear structures. For the aperiodic instability [with Re(ω)=0—odd Pierce zones], the unstable eigen-function saturates into new stationary nonlinear equilibrium. In the case of oscillatory instability [Re(ω)≠0—even Pierce zones], the instability results in the nonlinear oscillating standing wave. It is also shown that finite Larmor radius effects stabilize instability for parameters corresponding to a large number of Pierce zones, and therefore, only few first zones remain relevant.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".