A model of gas desorption and radiation during initial high voltage conditioning in vacuum
Bibliographic record
Abstract
Large quantities of gas are desorbed from the anode electrode during initial high-voltage conditioning of broad-area electrodes in a vacuum, equivalent to many monolayers and consist mostly of neutral molecules with an ionic component of a few percent. The ions are accelerated to the cathode, producing secondary electrons from the cathode and x-rays. There is still no reasonable explanation of these phenomena. Experiments have been performed to try to understand the source of the gas and radiation by using a residual gas analyzer to examine the desorption products from copper electrodes during initial high-voltage conditioning. The desorption products produced during initial high-voltage conditioning were then compared with those from thermal desorption of the same electrodes and surface preparation as they were heated in vacuum to about 600 °C, both with and without a high electric field present. Thermal desorption with an applied field showed a significant difference in the desorption spectrum compared with no applied field and produced a modest source of radiation that did not appear to be produced by field emission. At electrode temperatures beyond 450 °C, radiation production increased exponentially with temperature, likely produced by surface ionization of minor contaminants with a low ionization potential. These observations have been used as input to propose that the radiation and gas desorption observed during initial high-voltage conditioning is initiated by surface ionization from the many projections with high field enhancement factors on the anode surface.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 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".