Progress in characterization of the Photomultiplier Tubes for XENON1T\n Dark Matter Experiment
Bibliographic record
Abstract
We report on the progress in characterization of the Hamamatsu model\nR11410-21 Photomultiplier tubes (PMTs) for XENON1T dark matter experiment. The\nabsolute quantum efficiency (QE) of the PMT was measured at low temperatures\ndown to -110 $^0$C (a typical the PMT operation temperature in liquid xenon\ndetectors) in a spectral range from 154.5 nm to 400 nm. At -110 $^0$C the\nabsolute QE increased by 10-15\\% at 175 nm compared to that measured at room\ntemperature. A new low power consumption, low radioactivity voltage divider for\nthe PMTs is being developed. The measurement results showed that the PMT with\nthe current version of the divider demonstrated a linear response (within 5\\%)\ndown to 5$\\cdot$10$^4$ photoelectrons at a rate of 200 Hz. The radioactive\ncontamination induced by the PMT and the PMT voltage divider materials\nsatisfies the requirements for XENON1T detector not to exceed a total\nradioactive contamination in the detector of 0.5 evts/year/1tonn. Most of the\nPMTs received from the manufacturer showed a high quantum efficiency exceeding\n30\\%. In the mass production tests the measurements at room temperature showed\nclear single photoelectron peaks for all PMTs been under study. The optimal\noperation conditions were found at a gain of 2$\\cdot$10$^6$. The operation\nstability for most of the PMTs was also demonstrated at a temperature of -100\n$^0$C. A dedicated setup was built for testing the PMTs in liquid xenon using\nthe XENON1T signal readout components including voltage dividers, cables and\nfeedthroughs. The PMTs tested in liquid xenon demonstrated a stable operation\nfor a time period of more than 5 months.\n
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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".