Testing the integration of BaF<sub>2</sub>detectors into the 8π array: fast-timing measurements at TRIUMF
Bibliographic record
Abstract
BaF 2 detectors for picosecond gamma-ray decay lifetime measurements have been installed into the 8π gamma-ray spectrometer as a proof-of-principle for a possible installation of a full array of ten detectors. Using four detectors a test measurement of the half-life of the 2 + state in 152 Sm resulted in a value of 1.33(6) ns, compared with a published value of 1.396 ns. Measurements with a 26 Na stopped beam were performed with various master-trigger conditions. Using a master trigger of germanium–SCEPTAR–BaF 2 OR BaF 2 –BaF 2 , the FWHM of the BaF 2 –BaF 2 triggered events was found to be ∼290 ps compared with ∼1.9 ns for the germanium–SCEPTAR–BaF 2 triggered events. Simulations using GEANT4 of a suggested BaF 2 lifetime measurement system have been carried out. These illustrate the considerable gain in spectrum quality which can be expected using simple add-back protocols.
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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 | 0.002 |
| 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 | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".