Characteristics of heavy ion tracks in bubble detectors

Abstract

Characteristics of tracks created by heavy ions in bubble detectors have been studied in detail by using four types of super long (23 cm) , self-made bubble detectors and six species of high energy heavy ions: 12C, 28Si, 40Ar, 56Fe, 84Kr and 132Xe. The following characteristics of heavy ion tracks in bubble detectors have been recognized: (1) Heavy ion tracks are lines of tiny bubbles, which are measurable in coordinates, lengths and directions. (2) The threshold property is the governing factor for track formation. The essence of the threshold seems to be a critical rate of energy loss ( dE/ dX) c . The thresholds of three types of detectors are 1.69±0.03, 2.24±0.06 and 6.04±0.80 MeV mg −1 cm 2 , respectively, which are appropriate for the detection of heavy ions. (3) A maximum track length L m is fixed in a given type of detector for a given species of heavy ions, which proposes an approach to identifying high-energy heavy ions by measurement of maximum track lengths. (4) The linear bubble density dN/ dX (number of bubbles in unit length of track) in the first part of a track is correlated with the energy loss rate dE/ dX of the heavy ion in the detector. These characteristics propose another independent way to identify heavy ions through the dN/ dX – dE/ dX relationship.