A Fast Recycling Cloud Chamber and Pulsed Magnetic Field Equipment for Use with Pulsed Accelerators

Abstract

The objective of the work described here has been the development of cloud‐chamber apparatus for use with new high energy pulsed accelerators, such as the present 100‐Mev betatron and the 300‐Mev synchrotron now being constructed by the General Electric Company. The present cloud chamber is operated at a repetition period of about 5 seconds. An ``overcompression'' step in the cloud‐chamber cycle causes old tracks to be evaporated by momentary heating of the gas through compression. A pulsed magnetic field of 12‐milliseconds duration is used with this cloud chamber. The field is produced by discharging capacitors through Helmholtz coils. With these short current pulses, strong fields (20,000 gauss or more) are obtainable at fast cloud‐chamber recycling rates with relatively small heating of the coils.