Numerical evaluation of the cathode heating time during the post ignition and prethermionic electrode emission phase
Bibliographic record
Abstract
Summary form only given. Vortex water wall high pressure argon arc lamps are used to generate intense light and are capable of operating at radiative efficiencies greater than 50%. These lamps are being considered for use in a pulsed DC mode of operation in the next generation of RTP applications. The transition between the preignition state and the arc maintenance state has been observed to consist of a prethermionic electrode phase and a non LTE positive column phase. The prethermionic electrode phase is important from the standpoint of the power supply design in that it is responsible for a significant cathode layer voltage drop. Accurate experimental observations of the cathode spot are impossible because of the inner water wall. Thus a two dimensional finite difference analysis of the electrode heating time has been performed so as to infer an improved understanding of the cathode spot diameter. The cathode is made of tungsten coated copper and is cooled by water internally. The internal argon is maintained at a pressure of 7 atmospheres. The axial flow rate of the vortex gas is 9.434/spl times/10/sup -4/ m/sup 2//s. The diameter of the tube is 18 mm and thus the axial flow velocity is about 3.7 m/sec. Experimental results suggest that the thermonic heating time is in the order of 100 ms and thus the area being heated has an average diameter of 1 mm. From this we infer that the diameter of the cathode spot must be on the order of 1 mm. This diameter agrees with experimental results obtained by observing the spot size immediately after the arc is extinguished.
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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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.000 |
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".