Galactic and solar energetic particle observations during the increasing part of solar cycle 25 with EPD/HET and Metis on board Solar Orbiter
Bibliographic record
Abstract
Context. Galactic cosmic rays (GCRs) and solar energetic particles (SEPs) with energies greater than tens of megaelectron volts are at the origin of spacecraft deep charging. The High Energy Telescope of the Energetic Particle Detector instrument measures the particle flux incident on the Solar Orbiter spacecraft. An algorithm implemented in the processing electronics of the visible light (VL) instrument of the Metis coronagraph generates cosmic-ray matrices containing the pixels fired by high-energy particles. These independent observations allow us to monitor the secondary particle production into the spacecraft. Aims. We studied the GCR flux long-term variations during the ascending phase of solar cycle 25 and the evolution of two SEP events observed on July 24–26, 2023, and on February 9–14, 2024, above 80 MeV with the aim of evaluating the impact of galactic and solar high-energy particles on Metis. Methods. A Python tool named REBECCA has been developed for the automated analysis of the Metis cosmic-ray matrices. The number of observed particle tracks is compared to Monte Carlo simulations of the Metis VL bidimensional CMOS sensor used as a particle detector. Results. We present the modulation of the GCR energy spectrum from 2020 through 2024 above 100 MeV. The dynamics of two intense SEP events is also reported. Monte Carlo simulations indicate that the composition of particles in the cosmic-ray matrices is dominated by protons. Going from solar minimum to maximum, an increase in particles produced by cosmic rays in the spacecraft material surrounding Metis was observed. Conversely, during the whole evolution of SEP events, protons made up more than 90% of the particles. These observations were gathered near the ecliptic during a positive polarity epoch of the global solar magnetic field. Analogous studies will be conducted during the negative polarity epoch, within 1 au, both above and below the ecliptic plane, throughout the remaining duration of the mission.
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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 | 0.001 | 0.001 |
| 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".