The bubble chamber is making a comeback. For a quarter century several decades after its invention by Donald Glaser in 1953, bubble chambers filled with liquid hydrogen or heavy liquids played a leading role in particle physics. But their importance waned in the late 1970s as collision energies increased, events became crowded with tracks, and experimenters concentrated on the search for ever-rarer phenomena.
Now, however, the COUPP (Chicago-land Observatory for Underground Particle Physics) collaboration has reported the successful operation of a small innovative bubble chamber, 100 meters underground at Fermilab, in a search for stable, weakly interacting massive particles. 1 Called WIMPs, these putative particles are thought to constitute cosmological dark matter (see Physics Today, Physics Today 0031-9228 60 8 2007 16 https://doi.org/10.1063/1.2774084 August 2007, page 16 ). The chamber operates in a novel continuously sensitive mode. The collaboration’s spokesman is Juan Collar (University of Chicago).
The prototype bubble...
