Demonstration of a Cruciform Gamma-Ray Direction-Finder with both Self-Shielding and Compton Imaging Modes
Bibliographic record
Abstract
Effective technologies for locating radioactive materials across large areas are being developed as governments globally prepare for nuclear incidents. The present study investigates a Cruciform device that provides both Compton gamma imaging and simple direction-finding based on self-shielding. The Compton imaging and self-shielding modes perform well for detecting a single medium-energy source at multiple azimuthal angles. The performance degrades, however, for both modes at higher elevation angles. The self-shielding mode can determine the source direction even for low-energy sources when the Compton-scattering mode is impossible. The Compton-scattering mode on the other hand, provides gamma images of two equal-energy sources, where the self-shielding mode points to the source distribution centroid. In conclusion, the Cruciform detector helps localize distant sources, especially near the horizon. The Compton mode provides actual imaging capabilities in the presence of higher energy sources, while its self-shielding mode helps localize low-energy sources.
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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 | 0.001 |
| 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 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| 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".