ABSTRACT
So far we have discussed particle detectors that ultimately produce an electrical signal from the collection of charges. However, there are detectors in which the ionisation charges produced by the passage of a charged particle cause a local change to the molecular structure of a photographic emulsion, or a local change to the physical state of the detector medium, resulting ultimately in an image that reflects the path of the incoming particle in the position of these localised changes. Interpretation of these images requires optical survey that produces the data that is then used in the analysis.
