Effects of shock parameters on upstream energetic electron burst events
Bibliographic record
Abstract
Recent simulation results have revealed that energetic electron bursts are produced cyclically at the shock reformation period upstream of reforming shocks and are qualitatively very different from the continuous beam expected from time‐stationary shocks (Yuan et al., 2007a). This paper extends our previous studies by numerically investigating the dependence of electron burst events on shock parameters (the upstream plasma β and Mach number MA). The test particle approximation is made for electrons, and the electron trajectories are traced exactly in the time‐dependent electromagnetic field profiles, generated by one‐dimensional hybrid simulation code. Simulation results indicate that the upstream incoming electrons can be reflected nonuniformly or continuously depending on the shock parameters. Bursty energetic electron events take place when the plasma beta is low (β ≤ 0.4) and the shock Mach number is high (MA ≥ 6). Time‐varying loss cone, beam, and ring beam features are observed in the upstream electron distribution functions. The beam density, speed, average kinetic energy, and speed spread cyclically change with time by factor of ∼2–4. In contrast, continuously reflected electrons are observed for low beta (β ≤ 0.4), low Mach number (MA ≤ 4) shocks, even when the shock is reforming because the changes in shock fields are relative small. The electron burst events disappear and the observed upstream electron distribution function contours are steady state. A continuous electron beam is formed, which is qualitative the same as the beam from steady‐state shocks. Increasing the plasma beta (providing the shock is still reforming) has minor effects on the upstream electron beam features.
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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 | 0.002 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".