A rapid cycling hydrogen bubble chamber with high spatial resolution for visualizing charmed particle decays

For the purpose of directly detecting the decays of charmed particles, a rapid cycling hydrogen chamber with high spatial resolution has been constructed. In several runs it was exposed to 360 GeV proton and negative pion beams and has taken a total of 1.63 million pictures during more than 20 million expansion cycles. The resolved bubble diameters were around 40 μm with 80.5 counted bubbles/cm at 33 s−1 chamber and 17 s−1 camera cycling rates.