Spectrometry of the LET with track etched detectors - correlation with proportional counter measured spectra

A spectrometer of the linear energy transfer (LET) based on the chemically etched polyallyldiglycolcarbonate (PADC) track etched detector was develope d. The LET spectra are determined through the measurements of track paramet ers, it covers LET range between 10 and 700 keV/mum in tissue. A combined e xperimental and theoretical approach allowed the estimation of the critical dimensions of the sensitive volume necessary for developing a track to sev eral nm. It seemed interesting to us to compare the LET spectra obtained by this method with the microdosimetric spectra available on the basis of a c lassical experimental microdosimetry method, a tissue equivalent proportion al counter, for which the critical dimensions simulated are of the order of a few mum. Both methods of experimental microdosimetry were compared in the high energ y radiation reference fields and on the subsonic aircraft board. It was fou nd out that the microdosimetric distributions are similar; some differences are, nevertheless, observed. Further studies with the goal to explain them are outlined. (C) 2001 Elsevier Science Ltd. All rights reserved.