Two-step laser resonant ionization spectroscopy of neutral chromium
Bibliographic record
Abstract
At TRIUMF’s off-line laser ion source test stand, stepwise resonant laser ionization spectroscopy of neutral chromium (Cr I) was carried out, to find an efficient ionization scheme suitable for titanium sapphire (Ti:Sa) laser systems. With the excitation to the three different intermediate levels, 27728.811 cm −1 , 27820.198 cm −1 , and 27935.241 cm −1 , automated continuous laser-frequency scans using a frequency-doubled, grating-tuned Ti:Sa laser were performed. Rydberg series as well as autoionizing (AI) states were observed. From these results, the ionization potential (IP) of Cr I was determined as 54575.49(2) stat (3) sys cm −1 , which is one order of magnitude more precise than the previously reported 54575.6(3) cm −1 in NIST database. The ionization scheme using the observed AI resonance, λ 1 , v a c = 357.971 nm + λ 2 , v a c = 373.935 nm, was subsequently deployed to the online delivery of radioactive Cr + isotope beams for precision mass measurements. The online yields of 50 − 59 Cr + have been measured at TRIUMF-ISAC. • The ionization potential of chromium is determined with increased precision. • An efficient two-step resonant laser ionization scheme via an autoionizing resonance has been developed. • Radioactive Cr isotope beam yields using the two-step resonant laser ionization scheme were measured.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".