DEVELOPMENT OF A NEW DETECTION SCHEME TO PROBE PREDISSOCIATED LEVELS OF THE S1 STATE OF ACETYLENE
Bibliographic record
Abstract
A new spectroscopic scheme has been developed to probe the predissociated levels of the S$_1$ state of acetylene. Our new scheme is based on detection of visible fluorescence that is a result of multi-photon excitation of acetylene (resonantly through single rovibronic S$_1$ levels). The new detection scheme is not subject to decreases in fluorescence quantum yield of S$_1$ levels that lie above the predissociation limit, and laser scatter-light can be easily eliminated by a long-pass filter with a cutoff in the visible range. For the S$_1$ predissociated levels, the new detection scheme offers much improved signal-to-noise ratio compared to the conventional laser-induced fluorescence technique, based on detection of UV fluorescence from the S$_1$ levels. The new method is also easier to implement than various H-atom detection schemes, which involve one additional laser of different wavelength than the excitation wavelength. Based on the power dependence and lifetime of the fluorescence signals, electronically excited \\chem{C_2H} and/or \\chem{C_2} fragments are the likely emitters of the detected visible fluorescence. The new method is currently being used to extend the vibrational and rotational assignments of both gerade and ungerade levels of the S$_1$ state of acetylene in the region of the $cis$-$trans$ isomerization barrier, $>$1000 cm$^{-1}$ above the onset of S$_1$ predissociation.
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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) | 0.000 | 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".