Characteristics of heavy ion tracks in bubble detectors

Characteristics of tracks created by heavy ions in bubble detectors have be en studied in detail by using four types of super long (23 cm), self-made b ubble detectors and six species of high energy heavy ions: C-12, Si-28, Ar- 40, Fe-56, Kr-84 and Xe-132. The following characteristics of heavy ion tra cks in bubble detectors have been recognized: (1) Heavy ion tracks are lines of tiny bubbles, which are measurable in coo rdinates, 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 g iven 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 tr ack) in the first part of a track is correlated with the energy loss rate d E/dX of the heavy ion in the detector. These characteristics propose anothe r independent way to identify heavy ions through the dN/dX-dE/dX relationsh ip. (C) 2001 Elsevier Science Ltd. All rights reserved.