Pressure gradients in solid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mrow/><mml:mn>4</mml:mn></mml:msup></mml:math>He: Thermal quenching and annealing
Bibliographic record
Abstract
Torsional oscillator measurements on solid ${}^{4}$He show a frequency increase at low temperatures that suggests mass decoupling or nonclassical rotational inertia (NCRI). The magnitude of the NCRI appears to be larger when the helium is frozen and cooled rapidly. Annealing at high temperatures usually reduces the NCRI, with an accompanying drop in pressure, suggesting that defects are involved. Measurements in quenched or deformed crystals show a ${T}^{2}$ term in the temperature dependence of the pressure which has also been attributed to defects. We have built a cell with two capacitive gauges to measure the temperature dependence of the pressure and the magnitude of pressure gradients in solid helium. The helium can be melted in a few seconds using a heater embedded in the crystal and can be refrozen and quenched to low temperature very rapidly. From the maximum pressure differences in the cell, we infer a yield stress of order 4 kPa for solid ${}^{4}$He near melting. The pressure gradients relax when the temperature is raised above about 0.5 K via a thermally activated annealing process with an activation barrier of about 5 K. The existence of significant pressure gradients makes it difficult to measure the thermodynamic temperature dependence of the pressure, for example to extract information about glassy regions or other defects.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".