Experimental and analytical determination of 4He-ion track development in etched PADC detectors of type CR-39 and its consequences for particle spectroscopy with SSNT detectors

• Inter-comparison track length evolution L(t) measured by different authors on hand of 4He-ion tracks in SSNTD of type CR-39.
• Parameterization of the function L(t) and determination of parameters using new experimental data.
• Calculation of the track etch rate vT and comparison with other measurements.
• Calculation of the etching time necessary to get over-etched tracks.
• Confirmation of the measurement of over-etched track length s as convenient method for nuclear particle spectroscopy.

Nuclear particle spectroscopy with SSNTD can be more reliable performed by measurement of the track length of over-etched tracks than by the commonly applied method of track diameter calibration. This has been postulated by a recent paper by El Ghazaly in 2012. In the present work, this suggestion is studied by an analysis of most recent and unpublished new experimental data for the length evolution of 4He-ion tracks with increasing etching time. According to a proposal made by Azooz et al. in 2012 to the time dependent track length development can be described by an empirical analytical expression. Using these new data the parameters of this model were determined by a fitting procedure. The analytical description of the track length can be used to calculate related quantities like the track etch rate vT in dependence on the etching time and the corresponding depth of the track pit in the detector. The results calculated by this parameterization are compared with data obtained by the commonly applied troublesome point-by-point graphical solution. Finally, a formula was derived for calculation of the etching time necessary to get over-etched tracks.