Speaker
Description
Use of PIN diodes in spectrometry of low heavy ions poses some methodological challenges. One of them is correctly accounting for the so-called plasma delay effect (PDE) which is due to generation of plasma in a heavy ion track in the PIN diode. The PDE prevents precise measurements of a particle’s time-of-flight (TOF). In this presentation, we discuss new algorithm of time pick-off when using Si PIN diodes for measuring time-of-flight of heavy ions. The algorithm implies that the signal is split into two parts: the first part is approximated with a parabola which vertex coincides with the start of the signal and lies on the averaged baseline; and the second part is approximated by smoothing spline function. The proposed algorithm was experimentally verified with data acquired using two time-of-flight spectrometers, one with 252Cf source and another one, installed at IC-100 accelerator (FLNR, JINR). The results demonstrate that the developed algorithm allows obtaining unbiased fission fragment’s mass for the wide range of ion’s masses and energies, and thus provides a reliable “true” pick-off time for PIN diodes when used as time detectors.
