Bubble-chamber pressure cycle 2026-10-18
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Reduce pressure before beam arrival; photograph bubbles from several views, then recompress.[ref]
Unlike the Blackett-Occhialini triggered cloud-chamber experiment, Glaser used counter-controlled flashes after expansion. A detector trigger can select recording in sensitive liquid; subsequent expansion cannot recover a vanished latent track.[ref]
Figure 1.
Bubble-chamber pressure cycle and photographic readout
. Original functional diagram with an arbitrary time coordinate and chosen normalized pressure levels. The dashed equilibrium line assumes fixed temperature; no measured waveform, apparatus scale or historical delay is reproduced. Details.
The diagram deliberately separates the preparation through thermodynamics from the readout decision. Its green interval is a stipulated operating window, not a prediction from pressure alone. Excess superheating can increase unwanted nucleation; insufficient superheating can suppress tracks. A useful proposed sensitivity check holds the readout settings fixed while varying pressure or temperature, with matched background exposures. A proposed timing check moves the beam within the cycle; a proposed optical check varies flash delay to distinguish growing bubbles from changes in spatial resolution. These are experimental design examples, not additional historical measurements.
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