OPPOSITE EXPANSION SYSTEM FOR A RAPIDLY CYCLING BUBBLE-CHAMBER

To realize the operating cycle of expansion of the high-precision Liqu id-hydrogen rapid cycling hubble chamber, a hydropneumatic opposite ex pansion system was devised that has an operating frequency of up to 10 0 Hz and minimum cycle time of 3 ms. For the command and servo element s, we used electrically controlled, fast-running, hydraulic servo slid e valves. Owing to the use of the opposite expansion system, unbalance d inertial forces acting on the chamber body were reduced by more than 80 times compared with actuator on one side, which afforded more accu rate photo information.