Using A Cloud Chamber to Measure The Energy Of An Alpha Particle Source
Bibliographic record
Abstract
We studied the energy of alpha particles emitted during the decay of a 300 source using a cloud chamber. Tracks appearing in the chamber were recorded and measured using Kinovea video analysis software for 246 events over approximately 38 minutes. In the analysis, the source is modelled as an isotropic point source and full track lengths are calculated from the projections of the full 3-dimensional tracks into the XY plane in the cloud forming region. Applying a Gaussian fit to the data, the average track length was 1.68±0.04 cm. Using a stopping power of 1.1425MeV/cm and the same conversion factor used to determine the expected path length projection, the average value for the energy of the alpha particles was calculated to be 5.25±0.2MeV, which is within two standard errors of the accepted value of 5.49MeV.1 This shows cloud chambers can be an effective method of detecting alpha particles and accurately measuring energies.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".