The ionisation dependence of the registration temperature effect in solid state nuclear track detectors

Abstract

Abstract The Registration Temperature Effect in solid state nuclear track detectors has been investigated over a wide range of ionisation, using two types of polycarbonate detector and three types of doped allyl diglycol carbonate (CR-39) detector exposed to beams of 960 MeV/N uranium ions and 300 MeV/N iron ions at different temperatures. Beam spreaders were employed to provide a range of energies for both ions in each detector stack. The fractional change in signal strength per unit temperature change is found to be a strong, increasing function of ionisation for a given solid state nuclear track detector polymer at a given registration temperature. This fractional change in signal strength also appears to be an increasing function of charge for a given value of ionisation . In the case of both uranium ions and iron ions in polycarbonate track detectors, it is found that the mean fractional change in etch rate per degree centigrade, P, may be represented by an expression of the form P = KJM, in the energy regions studied, where K is a constant specific to the ion, J is given by Z2eff/β2 and the index, M, is ⋍ 0.75. These results constitute a major hardware “design driver” for future heavy nucleus experiments involving extended duration exposures of solid state nuclear track detectors on spacecraft.