Feb 20 – 22, 2017
FBK, Trento
Europe/Zurich timezone

Simulation and testing of thin silicon microdosimeters realized with 3D technology

Feb 22, 2017, 11:30 AM
20m
Aula Grande (FBK, Trento)

Aula Grande

FBK, Trento

Via Santa Croce, 77 38122 Trento ITALY

Speaker

Dr Marco Povoli (SINTEF MiNaLab, Oslo, Norway)

Description

Modern cancer treatments have become increasingly more sophisticated in the past years and therefore require a real-time, reliable radiation dose monitoring system in treatment planning and monitoring, with high spatial resolution. Silicon microdosimeters are excellent candidates as they are small in size and have high spatial resolution. The ease of coupling them to readout electronics makes them the first choice for a real time on-line system.

The devices in this study were realized with 3D technology on SOI wafers with active sensor thickness of 10 $\mu$m. This technique allows the formation of cylindrical sensitive cells with diameters of between 15 and 30 $\mu$m. The sensor design and configuration were based on information from previous microdosimeters developed by SINTEF MiNaLab in collaboration with the Centre for Medical Radiation Physics at the University of Wollongong, Australia. Numerical simulation was an important design tool and some results will here be shown.

Electrical and functional testing of the completed microdosimeters will be presented and discussed. The charge collection tests were performed at beam line ID21 at the ESRF, Grenoble, France and at ANSTO microprobe, using a sub-micron X-ray and He ion beams respectively demonstrating high definition of the sensitive volume. Testing on C-12 ion therapeutic beam at HIMAC, Japan demonstrated the ability of the MicroPlus probe with new sensors to derive RBE in a field and dose equivalent in out of field with submillimeter spatial resolution.

Finally, the latest results from a fabrication technique aiming at integrating tissue-equivalent materials for embedding of SVs directly onto the sensor will be presented. The final scope of this process is to achieve the generation of secondaries by gamma and neutron radiation exactly like in human tissue, allowing the application of these microdosimeters for dose equivalent measurements for personal radiation protection in mixed radiation fields.

TRACK 3D Sensors

Primary author

Dr Marco Povoli (SINTEF MiNaLab, Oslo, Norway)

Co-authors

Prof. Anatoly Rosenfeld (Centre for Medical Radiation Physics, University of Wollongong, Australia) Mr Andreas Tefre Samnøy (Department of Physics and Technology, University of Bergen, Norway) Dr Angela Kok (SINTEF MiNaLab, Oslo, Norway) Dr John Morse (European Synchrotron Radiation Facility, Grenoble, France) Mr Lachlan Chartier (Centre for Medical Radiation Physics, University of Wollongong, Australia) Dr Linh Tran (Centre for Medical Radiation Physics, University of Wollongong, Australia) Marco Petasecca (Center for Medical Radiation Physics, University of Wollongong, Australia) Prof. Michael Lerch (Centre for Medical Radiation Physics, University of Wollongong, Australia) Dr Murielle Salome' (European Synchrotron Radiation Facility, Grenoble, France) Nicola Pacifico (Department of Physics and Technology, University of Bergen, Norway) Mr Øyvind Lye (Department of Physics and Technology, University of Bergen, Norway)

Presentation materials