An APD-based quad scintillator detector module with pulse shape discrimination coding for PET
Bibliographic record
Abstract
A detector module allowing individual crystal identification without analog coding is proposed. The basic cell is made of a 2/spl times/2 array of scintillators having different decay times that can be identified by pulse shape discrimination. A 16 pixel module consisting of a 2/spl times/2 array of these quad scintillator cells coupled to a 2/spl times/2 avalanche photodiode (APD) array was assembled and tested. In this design, the signal-to-noise ratio can be optimized in two ways: (a) the electronic noise in individual APD channels is minimized by avoiding light sharing between photodetectors; (b) light collection efficiency is improved by eliminating light septa within cells to allow scintillation light propagation across crystals. All four crystals in a BGO/LSO/YSO/CsI(T1) assembly can be clearly separated and individually gated for energy. An energy resolution better than 13% can be obtained in all pixels for 511 keV gamma-rays.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.003 | 0.007 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.003 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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; both teacher heads agree on what is shown here.
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".