Bibliographic record
Abstract
Abstract A “twin‐coronal mass ejection (CME)” scenario has been proposed recently to account for extreme solar energetic particle (SEP) events. In this scenario, two CMEs erupt from the same or nearby active regions within a short period of time. They both drive shocks, and the presence of the first CME‐driven shock leads to a more efficient particle acceleration process at the second shock. All Ground Level Enhancement events in solar cycle 23 and many large SEP events support the twin‐CME scenario. In a subset of these events, the two CMEs are separated by only a few minutes and particle acceleration is further enhanced due to particles reflecting between the two shocks. Here we examine particle acceleration at a parallel shock pair using a test particle approach. We follow single‐particle trajectories using two methods: close to the shock we follow particle's motion by solving the Lorentz equation directly; beyond certain distances, we ignore the gyration degree of freedom of a particle and approximate its motion by its guiding center motion and pitch angle scattering. We do not consider wave generation due to the streaming protons at both shocks. Instead, we assume the background turbulence upstream of the first shock is given and follow its transmission to the downstream of the second shock. Our results show that the intensity of accelerated particles in the shock pair case is significantly enhanced over a single shock case, and the maximum energy obtained in a shock pair system can be a few to 10 times that of a single shock case.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".