Thermodynamic temperature of the triple point of xenon measured by refractive index gas thermometry
Bibliographic record
Abstract
Measurements of the refractive indices of helium and argon using a quasi-spherical microwave resonator and upgraded experimental protocol are reported at the temperatures of the triple points of water and xenon. The results at the triple point of water are used to determine the compressibility of the resonating cavity, which is bounded by the copper shell of the resonator. This experimentally-determined compressibility is consistent with the literature value for copper, but with much smaller measurement uncertainty. The measured compressibility is extrapolated to the triple point of xenon, and combined with the refractive index results at that temperature to determine the thermodynamic accuracy of the International Temperature Scale of 1990 (ITS-90): mK at ITS-90 temperature K, corresponding to a xenon triple point thermodynamic temperature of K. The experimental compressibility is further extrapolated to the triple points of argon, oxygen and neon, and used to re-analyze earlier refractive index gas thermometry measurements made using the same resonator, yielding updated values with reduced uncertainties: mK at T 90 = 83.8058 K, mK at T 90 = 54.3584 K, and mK at T 90 = 24.5561 K. The ITS-90 thermodynamic accuracy results of the present refractive index gas thermometry study agree with those previously reported by acoustic gas thermometry and dielectric constant gas thermometry.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".