A Mass Selective Transfer Line for the Injection of Molecular Ions in a Cold Uniform Supersonic Flow
Bibliographic record
Abstract
The astrochemical molecular inventory has recently been enriched with the detection of several anions (C4H−, C6H−, C8H−, CN−, C3N−, and C5N−). So far, the chemical pathways leading to the formation/destruction of these species have hardly been investigated. At the Physics Institute in Rennes, we explore the reactivity (reaction rates, product identities, and branching) of these species by means of uniform supersonic flows issued from specifically designed Laval nozzles, a technique that provides an ideal environment to thermalize gas-phase reactants and products at low temperature (20-30K). In this poster, we report on the design considerations of our current instrumental developments regarding a customized, dedicated ion source that enables the injection of significant amounts of mass-selected ions into the dense isentropic core of our uniform supersonic flows. Particular attention is given to reaching the best compromise between mass-selection at low pressure and flow injection at elevated pressure made possible by ion optics simulations in realistic flow fields. Experimental data to characterize transmission efficiency as well as first results on the reactivity of key interstellar anions are also presented.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".