Broadening alpha registration energy range of 250 μm polycarbonate detectors by a single 50 Hz–HV ECE method

• Alpha particle tracks were studied in 250 μm PC applying 50 Hz–HV ECE method.
• Efficiency and diameter were determined versus field conditions, duration and energy.
• Efficiency, diameter and background density increase as HV and ECE duration increase.
• Alphas of ∼300 keV to ∼4.5 MeV were detected with efficiency up to ∼70% at the Bragg peak.
• Some characteristics of 50 Hz–2 kV and 2 kHz–800 V methods are compared.

Our recent studies on efficient detection of nitrogen and helium ions in a plasma focus device and alpha particles in 1 mm thick polycarbonate track detectors (PCTD) by 50 Hz–HV ECE method in PEW (potassium hydroxide, ethanol, water mixture) solution at 26 °C for 10 h proved having promising results. In order to further study the characteristics of the method and extend the applications, studies were performed by using 250 μm PCTDs by 50 Hz–HV method instead of commonly applied 2 kHz–800 V or similar conditions. Alpha detection efficiency, mean track diameter, detection energy range, lower and upper registration energy thresholds and track shapes as well as background track density and diameters were studied by varying field conditions, ECE durations and alpha energies. The efficiency, meantrack diameter and background in general increased as high voltage and ECE duration increased. The optimum ECE conditions were determined to be 50 Hz–2 kV in PEW solution at 26 °C for 2–3 h. The 50 Hz–2 kV method provides some unique characteristics compared to 2 kHz–800 V in terms of having a higher efficiency in a broader efficient registration energy range ∼300 keV to ∼4.5 MeV, smaller track diameters and thus capability to detect higher fluencies of charged particle at the cost of a relatively higher background. Further research is in progress on alpha registration studies.