Technical report. From Abstract : "Spark counters of the wire plate type are rugged and simple, and their sensitivity is directly proportional to the specific ionization of incident particles. Spark counters are insensitive to beta and gamma radiation but readily respond to alpha particles. With a suitable converter, the spark counter can also be employed as a neutron counter. Spark counters thus appear to be very good candidates for the measurement of neutron flux at reactor startup, where the high background of gamma radiation can be troublesome to other types of counters. A spark counter of cylindrical geometry was built and shown to have adequate sensitivity and stability for such duty."