Comment on electron-impact excitation cross section measurements for He-like xenon
Bibliographic record
Abstract
We discuss lower-than-predicted collisional–excitation cross sections for helium-like xenon measured at an Electron Beam Ion Trap facility. In a review paper (H. Chen and P. Beiersdorfer. Can. J. Phys. 86, 55 (2008)), the authors find a significant effect due to the Breit interaction between the free and the bound electrons in the excitation process of He-like xenon. The authors state that the agreement between the measured and calculated cross section values can only be found when the generalized Breit interaction is included in the calculations. We have performed new calculations with a multi-configuration Dirac–Fock code, as well as with the Penn State University suite of codes, and our conclusions are that the contribution of the Breit interaction is much lower than found in the calculations presented in the abovementioned article. In fact, our predictions are subsequently almost twice as large as the experimental values. We present these considerations in hopes of motivating new experimental investigations.
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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 | 0.004 | 0.022 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.003 |
| Scholarly communication | 0.001 | 0.003 |
| Open science | 0.005 | 0.001 |
| Research integrity | 0.007 | 0.009 |
| Insufficient payload (model declined to judge) | 0.006 | 0.004 |
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".