Ejecta from liquid gallium during planar impact experiments
Bibliographic record
Abstract
When a solid or liquid metal surface is subject to shock loading, ejecta may be produced by two separate phenomena: growth of surface asperities from Richtmyer-Meshkov instability (RMI); and cavitation (micro-spall) at the surface from shock release if the material is liquid or shock-melts. In the present study we shock-loaded liquid gallium to modest pressures (4.5 GPa). The liquid gallium was sealed in a steel capsule and impacted with an explosively-drive steel flyer plate. Thickness of the gallium sample was varied to change the shock loading from a square pulse (supported) to an unsupported triangular pulse. Two surface conditions were also considered: a clean liquid surface, and an oxidized surface. Gallium free surface and ejecta cloud velocities were recorded using photonic Doppler velocimetry. Ejecta mass flux was measured using piezoelectric pins. Ejecta mass flux versus ejecta cloud velocity was extracted from integration of the pin voltage response assuming inelastic collision. The oxidized samples generated high-speed ejecta (uejecta/usurface > 1.5), indicative of RMI-driven jetting of asperities. The samples with liquid surfaces generated only low-speed ejecta (uejecta/usurface < 1.5), indicative of only micro-spall. For the oxidized samples, the unsupported shock case generated significantly more, higher-speed, ejecta compared to the supported shock case. In contrast, there was little influence of shock support on the mass flux profile for the clean liquid surface cases.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| 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 teacher head, 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".