Development of a sorption-based Joule-Thomson cooler for the METIS instrument of E-ELT
Bibliographic record
Abstract
METIS, the Mid-infrared E-ELT Imager and Spectrograph, is one of instruments in the European Extremely Large Telescope. Its detectors require cryogenic cooling at three temperature levels below that of liquid nitrogen, 8 K, 25 K, and 40 K. Vibration-free cooling is one of the technologies that were identified as the most needed in the development of the METIS instruments. Therefore, a useful cooling technology based on sorption Joule-Thomson (JT) coolers was proposed for the METIS by University of Twente. The scope of this thesis is to provide vibration-free cooling at multiple cryogenic temperatures for the optics and infrared detectors in large ground telescopes. The thesis focuses on developing a vibration-free sorption-based JT cooler for the METIS instrument in the E-ELT. The research is characterized by challenges such as multiple cooling levels, large cooling capacity with considerable efficiency and size, manufacturability and costs, etc.. The development initialized by gathering basic inputs, such as adsorption isotherms and optimization of the working fluids according to the cooling requirement. A conceptual baseline design of the METIS cooler chain was first defined to present a first impression, particularly in terms of the input power and size. Based on this baseline design, three demonstration setups were built and tested to validate the cooler design: 1. Full-scale 8 K helium JT cold stage; 2. Scaled helium sorption compressor; 3. Scaled 40 K neon sorption JT cooler.
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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) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".