The Rosenblum Spark Counter: A New Counter for the Detection of Fast Ionizing Particles

Abstract

An investigation has been made of the characteristics of the α-particle wire counter recently demonstrated by Rosenblum(1), and to examine the possibility of using it for the detection of less ionizing particles. A particle is recorded by the passage of a spark between a fine wire and a flat plate in close proximity, and between which a corona discharge exists in the open air. Counters of this type can be constructed with a plateau of about 2500 V. in length by using higher voltages than those originally suggested by Rosenblum. The accidental rate is less than one in 4 hr. and the dead time is about 10-4 sec. The recording properties of the counter are shown to depend on the direction of the incident particles in passing through the sheath of corona discharge surrounding the wire. By using a wire-plate system, some objections to the earlier point-plate counter of Greinacher(2) are eliminated. The result is an instrument of great simplicity and which might have important advantages for many purposes. When the counter is working in an atmosphere of carbon dioxide or a 1% mixture of this gas with air, it is also capable of detecting protons and fast electrons. Such a development will greatly increase its field of application.