Bubble Chamber
Trails of bubbles are produced by high-energy charged particles moving through the superheated liquid hydrogen in this artist's rendition of a bubble chamber. There is a strong magnetic field perpendicular to the page that causes the curved paths of the particles. The radius of the path can be used to find the mass, charge, and energy of the particle.
Source
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"OpenStax College, College Physics. November 26, 2012."
http://cnx.org/content/m42375/latest/?collection=col11406/1.7
OpenStax CNX
CC BY 3.0.