Bibliographic record
Abstract
Limits on the efficiency of several thruster configurations are discussed. The efficiency of the Pulsed Plasma Thruster is reduced when part of the magnetic field energy that is converted into particle energy does not become directed kinetic energy but rather thermal energy. The partitioning of the power when the propellant exhibits slug, snowplow or specular-reflection acceleration is analyzed. It is suggested how to distribute the propellant mass along the accelerating channel so as to efficiently use this thermal energy. Steady acceleration to supersonic velocities is examined in two configurations: the Magneto-Plasma Dynamics (MPD) thruster and the Hall thruster. Limits on the efficiency of the MPD thruster in a nondiverging geometry are derived. The efficiency in the self-field acceleration is higher than in the azimuthal applied-field acceleration. These limits can be overcome in a converging–diverging geometry, analogous to the Laval nozzle, in which the efficiency can approach unity. The acceleration efficiency in the Hall thruster becomes unity for an infinite magnetic Reynolds number even in a nondiverging geometry. The efficiency can be enhanced by the pressure that results from electron heating or by employing segmented emitting electrodes.
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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 | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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".