Use of Flexible Plastic Tubes for Automatic Recording of Particle Tracks

Abstract

Flexible tubes of plastic material (such as polyethylene, polyvinyl, nylon) with a mixture of noble gases flowing through them can be the basic elements of a new type of “electrically pulsed chamber” (EPC), which is potentially useful for the automatic recording of charged particle tracks in many experiments in nuclear and high-energy physics. Like the flash tube hodoscope chamber¹, or the discharge chamber² derived from it³, or any of the subsequent types of EPCs (spark chambers, streamer chambers and so on) this new track detector is sensitized by a large electric pulse (several kV cm⁻¹) applied immediately after the occurrence of a physical event selected by means of external counters and some associated logic circuitry. Under these conditions a luminous discharge occurs in those plastic tube elements through which ionizing particles have passed, but not in the other elements if the tubes are protected from external light. Photon emission and secondary ionization processes ensure that the discharge propagates along the whole length of the tube element, just as in the case of the ordinary glass flash tube¹. The discharge is interrupted, however, at the grounded metal boxes which connect each plastic tube element to the next one (Fig. 1).