The particular features of the photographic method of detecting
atomic particles enabled us to establish the existence of transient forms of matter. Cecil Frank Powell
(1903-1969; Nobel 1950)
(2019-07-30) Scintillation Counters
(Crookes, 1903)
Now best used with photomultipliers (Curran & Baker, 1944).
This is the earliest proper particle detector.
It was famously used by Hans Geiger and Ernest Marsden
in the gold-foil experiment
supervised by Rutherford
which established the existence of the atomic nucleus (1909).
Without the help of modern photomultipliers, the tiny flashes on the surface of the
scintillating material (originally, ZnS) had to be observed in
total darkness under a microscope.
Arguably. Hans Geiger soon invented the
counter named after him to improve
his own working conditions.
They took much advice from the inventor Don Glaser himself to build their first
propane bubble chamber
of 10 cm diameter
(later upgraded to 15 cm then 30 cm)
and soon came up with the key idea of recompressing the liquid milliseconds after an expansion.
This innovation collapses all bubbles before they can rise and collect at the top of the vessel,
making it possible to cycle the apparatus several times per second.
