Electron impact excitation studies of laser-excited and ground-state barium and ytterbium
Bibliographic record
Abstract
The research presented in this dissertation was performed in the Atomic, Molecular and Optical (AMO) physics laboratory at the University of Manitoba. Atomic beams of the two-valence-electron heavy atom systems, barium and ytterbium, were investigated with low energy electron scattering and optical emission studies. Both the ground states and laser excited states were investigated as a function of incident electron beam energy from 10 eV to 50 eV. Measurements of relative cross sections and polarization for 583 nm and 554 nm line emission from the (6s7p)1P1 and (6s6p)1P1 states of barium excited by electron impact from both the ground states and the optically pumped metastable (6s5d)1D2 are reported. Data are normalized to absolute cross sections for the ground state (6s2)1S0→(6s6p)1P1 state transition due to electron scattering, with corrections for branching ratios and cascading from higher states to deduce the total level excitation cross sections. Results are also presented for the first studies of the 399 nm line emission from laser-excited ytterbium, yielding an upper limit on the apparent cross section for the (6s6p)3P1→(6s6p)1P1 transition. Results are compared with the latest theoretical models and previous data, where available.
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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 | 0.000 |
| 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) | 0.003 | 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 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".