Commissioning of the Canadian Primary Standard for Low Dose Rate Brachytherapy
Bibliographic record
Abstract
The purpose of this project is to investigate the performance of the NRC WAFAC and commission it as a primary standard for calibrating LDR sources.Significant enhancements were implemented to the WAFAC for improving signal to noise ratio, measurement reproducibility and eliminating electric field distortion.The validation of the WAFAC, comparing to the existing NRC primary standard, shows that the agreement between the two devices is within the combined measurement uncertainties of less than 0.5 %.The measurements made with a 125 I LDR seed gave results that were consistent at the 1 % level with the manufacturer's stated seed activity (traceable to NIST).The polarity effect and aperture size effect had been studied during the commissioning.The overall k = 2 standard uncertainty in the determination of air kerma strength using the NRC WAFAC is estimated to be 2.6 %, which reaches the target uncertainty for the standard.iii
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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 | 0.008 | 0.012 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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".