The 100μ\muPET project: A small-animal PET scanner for ultra-high resolution molecular imaging with monolithic silicon pixel detectors

Recent developments in semiconductor pixel detectors allow a new generation of positron-emission tomography (PET) scanners that, combined with advanced image reconstruction algorithms, will allow for a few hundred microns spatial resolutions. Such novel scanners will pioneer ultra-high resolution molecular imaging, a field that is expected to have an enormous impact in several medical domains, neurology among others. The University of Geneva, the École Polytechnique Fédérale de Lausanne, and the University of Lucerne, have launched the 100μPET project that aims to produce a small-animal PET scanner with ultra-high resolution. The scanner will be composed of 4 ”towers”, each containing a stack of 60 monolithic silicon pixel sensors for the direct measurement of the annihilation photons. The sensors are 270 μm thick, providing unprecedented depth-of-interaction measurement. Monte Carlo simulations were done simulating different scanner conditions, resulting in a spatial resolution down to 0.2 mm FWHM and a sensitivity of 3.2%

Time resolution of a SiGe BiCMOS monolithic silicon pixel detector without internal gain layer with a femtosecond laser

Abstract The time resolution of the second monolithic silicon pixel prototype produced for the MONOLITH H2020 ERC Advanced project was studied using a femtosecond laser. The ASIC contains a matrix of hexagonal pixels with 100 μm pitch, readout by low-noise and very fast SiGe HBT frontend electronics. Silicon wafers with 50 μm thick epilayer with a resistivity of 350 Ωcm were used to produce a fully depleted sensor. At the highest frontend power density tested of 2.7 W/cm 2 , the time resolution with the femtosecond laser pulses was found to be 45 ps for signals generated by 1200 electrons, and 3 ps in the case of 11k electrons, which corresponds approximately to 0.4 and 3.5 times the most probable value of the charge generated by a minimum-ionizing particle. The results were compared with testbeam data taken with the same prototype to evaluate the time jitter produced by the fluctuations of the charge collection. </p