| Popis: |
Historically, bubble chambers have been expanded by either hydraulic or gas‐actuated pistons or diaphragms. Such systems are easily capable of generating the necessary pressure drops (e.g., Δp pf 60 psi from a static level of 90 psi), even in chambers of 1 m3 volume or greater. Their chief limitation lies in the relatively low cycle rate (1–10 cps) inherent in such techniques. Various acoustical systems offer attractive alternatives. In particular, an electromagnetic driver (as used in vibration studies) has been tested as an expansion system on model liquid‐hydrogen bubble chambers at SLAC, and a program to build a working chamber incorporating this technique is under way. The possibility of achieving the necessary expansion using standing sonic waves (frequencies from 180 to 8000 cps), and various means of generating such waves, are also being investigated. |
