A mechanical tuner for the ISAC-II quarter wave superconducting cavities
Bibliographic record
Abstract
TRIUMF is developing a new mechanical tuner system capable of both coarse (kHz) and fine (Hz) frequency adjustments for maintaining frequency lock on the superconducting quarter wave cavities of the ISAC-II heavy ion linac. A 1 mm thick Niobium plate at the high field end of the cavity is actuated by a vertically mounted permanent magnet linear servo motor, at the top of the cryostat, using a 'zero backlash' lever and push rod configuration through a bellows feed-through. The system resolution at the tuner plate center is /spl sim/0.055 /spl mu/m (0.3 Hz) with a dynamic range of 8 KHz and a manual coarse tuning range of 33 kHz. In cold tests with a prototype quarter wave cavity the tuning system's ability to compensate perturbations indicated a bandwidth up to 100 Hz. A large mechanical resonance at 20 Hz should be eliminated in the on-line device. The rf control is based on a self-excited loop with a locking circuit for amplitude and phase regulation. The tuner is fed a position signal integrated from the control loop phase error. Details of the mechanical device and results of open and closed loop cold tests will be given.
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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) | 0.000 | 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 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".