Derivation of V function for LR 115 SSNTD from its partial sensitivity to 222Rn and its short-lived progeny

Solid-state nuclear track detectors (SSNTDs) have been widely applied for measurements of environmental concentrations of 222Rn and its progeny. The V function for an SSNTD is important for understanding the track development in the SSNTD as well as for real life applications. The partial sensitivity ρi of the LR 115 detector applied in the bare mode to 222Rn and its short-lived progeny is related to the equilibrium factor F through the proxy equilibrium factor Fp. On the other hand, ρi is also dependent on the removed active layer thickness during chemical etching, which is related to the V function for the LR 115 detector. In the present paper, the experimentally obtained ρi values of the LR 115 detector for different removed active layer thickness are used to derive the V function for the LR 115 SSNTD, which took the form of the Durrani-Green's function, i.e., V=1+(a1-bar -a2R+a3-bar -a4R)(1--bar -a5R), with the best-fitted constants as a1=14.23; a2=0.48; a3=5.9 and a4=0.077 (a5=1)