Detection, dosimetry and microdosimetry using high energy C-12 beams

Samples of polyallyldiglycolcarbonate (PADC) track etch detectors (TED) wer e exposed to high energy C-12 nuclei at the particle beam of the Dubna sync hrophasotron. The energy of C-12 nuclei varied between 0.1 and 1.5 GeV per amu. At the low studied energies the linear energy transfer (LET) of these nucle i is higher than the detector threshold value. Then, the primary particle t racks are directly etched in the detector surface. The detection efficiency approaches to 100% at perpendicular incidence. Their LET has been establis hed by means of standard authomatized procedure recently developed. The LET values found here are in good agreement with theoretical ones. At 1.5 GeV per amu (LET similar to 8.4 keV mu m(-1)) the secondary particle tracks were evaluated in all the exposed detectors. The energy deposited b y these particles was compared to the energy deposited through primary ioni zation losses. It was found out that its contribution to the total dose is relatively lower than for protons of comparable energies. In some of these samples even the tracks of the primary nuclei were observed. It follows tha t the detection threshold of the developed LET spectrometer should be below 10 keV mu m(-1).