A Novel Hybrid Microdosimeter for Radiation Field Characterization Based on the Tissue Equivalent Proportional Counter Detector and Low Gain Avalanche Detectors Tracker: A Feasibility Study

In microdosimetry, lineal energies y are calculated from energy depositions ? inside the microdosimeter divided by mean chord length , whose value is based on geometrical assumptions both detector and radiation field. This work presents an innovative two-stages hybrid (HDM: for microdosimetry) composed a tissue equivalent proportional counter silicon tracker made of 4 low gain avalanche diode. design provides direct measurement deposition in as well particles tracking with submillimeter lateral spatial resolution. The data collected allow to obtain real track traversed each particle thus estimates microdosimetry spectra without approximation. Using Geant4 toolkit, we investigated HDM performances terms detection efficiencies when placed water exposed protons carbon ions therapeutic range. results indicate that approximation underestimate short track, which often characterized high can be biologically relevant. Tracking efficiency depends diode configurations: 34 strips sensors have higher but lower resolution than 71 sensors. Further studies will performed experimentally optimize bases field interest.The main purpose improve assessment biological effectiveness via microdosimetric measurements, exploiting new definition ( yT ), defined particle.