Testing Two High Heat Flux Liquid Nitrogen Jet Impingement Evaporative Coolers
Bibliographic record
Abstract
Since the efficiency of high power components, such as doped Yttrium Aluminum Garnet (YAG) laser amplifiers, improves dramatically at cryogenic temperatures, a cooling system capable of high performance at cryogenic temperatures is desirable. Because of its many favorable qualities, pool boiling liquid nitrogen (LN2) is the cryogenic cooling system of choice. However, as the power density of systems increases and laser systems migrate to agile hosts; the limitations of pool boiling become more restrictive. To expand beyond the flux and orientation limits of LN2 pool boiling, two systems based on jet impingement were developed and tested. The first cooled fluxes up to 70 W/cm 2 at a heat load of 1500 W. It demonstrated temperature stability, variations less than 1.5 K at 60 W/cm 2 over 20 minutes. The second system provided 50 W/cm 2 cooling (500 W total) while inverted, operating against gravity.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".