Impact of charge carrier trapping on amorphous selenium direct conversion avalanche X-ray detectors
Bibliographic record
Abstract
A cascaded linear system model is developed to determine the detective quantum efficiency (DQE) considering trapping of charge carriers in the absorption layer of an amorphous selenium multilayer direct conversion avalanche detector. This model considers the effects of charge carrier trapping and reabsorption of K-fluorescent X-rays on the frequency-dependent DQE(f). A 2-D simulation is performed to calculate the actual weighting potential in the absorption layer, which is used to calculate the amount of collected charge. It is observed that the DQE(f = 0) reduces from 0.38 to 0.19 due to charge carrier trapping in the absorption layer having a thickness of 1000 μm when the electronic noise is 1500 electrons per pixel. The avalanche gain enhances the signal strength and improves the frequency dependent DQE(f) by overcoming the effect of carrier trapping and as well as the effect of the electronic noise. The simulations suggest that avalanche gain of 35 and 20 are required to overcome the effect of the electronic noise of 1500 and 700 electrons per pixel, respectively.
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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) | 0.001 | 0.001 |
| 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) | 0.001 | 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; 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".