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https://uni-bonn.zoom.us/j/64173952572?pwd=ejVCZ0V2MGQ3Qk42aWxJYXNjUTVidz09
Meeting-ID: 641 7395 2572
Kenncode: 141393
At the Department of Medical Physics of LMU Munich a demonstrator proton irradiation platform for
preclinical research with tumor bearing mouse models has been developed and commissioned (ERC grant
725539, PI K. Parodi). It converts injected clinical proton beams to low energies of 20 to 50MeV and small
diameters of O(1mm) to enable precise, image-guided irradiation of mice.
For real-time beam monitoring and control we have developed a transparent ionization chamber. It provides
beam intensity information and is able to measure the beam position and size in two dimensions. The photo-
lithographically structured electrodes consist of 10μm Kapton foil, coated with 40nm aluminum. The
unsegmented plane is read out with an in-house developed, FPGA controlled gated integrator.
The profile of the produced beam has been in depth characterized with an optically read out bulk
Micromegas detector with ITO glass anode, coupled to a pixel Electron Multiplying CCD. The device has
been operated at particle rates from single to 107Hz and proton energies between 20 to 70MeV in multiple
testbeams.
A proton computed tomography system (pCT) will enable object imaging, by combining particle position
information with a residual energy measurement of the transmitted particles with energies between few and
80MeV. We have developed ultra-thin floating strip Micromegas detectors with two-dimensional
strip readout structures, consisting of 9um thick aluminum electrodes on a 32um Kapton substrate. For
determining the residual energy with high precision, we have built a Time Projection Chamber (TPC) as rear
detector of the imaging system with a discharge insensitive floating pad Micromegas readout structure.
Prototypes and a partially equipped TPC have been tested in several particle beams. The pCT detectors are
read out with the RD51 VMM3a Scalable Readout System.
The gaseous detectors were developed and built in-house at LMU Munich, profiting from a dedicated ISO3/5
cleanroom and photolithography laboratory. The systems have been tested individually in several test beams
and recently all together in a measurement campaign at the Danish Center for Particle Therapy in Aarhus,
during whichthe SIRMIO platform has demonstrated to be able to automatically deliver intensity modulated,
pre-clinical proton treatment plans into dosimetric phantoms.
I will present and discuss the construction methods, commissioning and performance of the gaseous
detectors and compare to simulated results and to results from reference dosimeters.