Bibliographic record
Abstract
This paper details the work done on the design of the faraday cups for the DIAMOND light source. Diamond has faraday cups in positions covering the complete energy range of the machine from the 90keV gun to the 3GeV stor-age ring. The Linac cups were modified from an existing design, while the higher energy designs were done using Monte Carlo code. The Monte carlo led designs achieved an elec-tron capture rate of around 99%, allowing them to be used with reasonable certainty as calibration references. Due to the modest 5Hz repetition rate of the electron gun, power loading of the structures is minimal and active cooling is not required for any of the cups. Ablation is also not thought to be a significant problem for these designs. OVERVIEW Diamond light source is a 3GeV 3rd generation syn-chrotron. The electrons are initially ejected from a 90keV gun. A linear accelerator increases the energy of the elec-trons to 100MeV. A booster ring further increases the en-ergy to 3GeV. Finally the beam is injected into the storage ring to generate the synchrotron radiation [1]. Faraday cups are a basic charge capture device which can be used as reference points for current measurement calibration. Diamond has faraday cups after the 90keV gun and the 4MeV bunching section, in the linac to booster transfer line at 100MeV and at 3GeV in the booster to stor-age ring transfer line. An initial design decision was made to make the designs passive to increase reliability and reduce complexity. Due to the modest 5Hz repetition rate of the electron gun, power loading of the structures is minimal and active cooling is not required for any of the cups. The 90keV and 4MeV cups were modified from an exist-ing design using analytical formulæ and MathCAD. Monte carlo modeling was used to confirm the new design. The high energy 100MeV and 3GeV designs were done using the EGSnrc Monte Carlo code1 from the national research council Canada, with MatLAB being used for interfaces and post analysis. This paper will cover the basic methodologies used to obtain each design as well as the final design details and expected performance.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 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".