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MIMOSIS is a CMOS Monolithic Active Pixel Sensor developed to equip the Micro Vertex Detector of the Compressed Baryonic Matter (CBM) experiment at FAIR/GSI. The sensor will combine an excellent spatial precision of $5~\mu m$ with a time resolution of $5~\mu s$ and provide a peak hit rate capability of $\mathrm{\sim 80~ MHz/cm^2}$. To fulfill its task, MIMOSIS will have to withstand ionising radiation doses of $\sim 5~ \mathrm{MRad}$ and fluences of $\sim 7 \times 10^{13}~\mathrm{n_{eq}/cm^2}$ per year of operation. This paper introduces the reticle size full feature sensor prototype MIMOSIS-2.1, which was improved with respect to earlier prototypes by adding on-chip grouping circuts and by improving the analog power grid. Moreover, it features for a first time a $50~\mu m$ epitaxial layer, which is found to improve the performances of the non-irradiated device significantly. We discuss the in beam sensor performances as measured during beam tests at the CERN-SPS., Comment: 6 pages, 7 figures

The Micro Vertex Detector (MVD) is the most upstream detector of the fixed-target Compressed Baryonic Matter Experiment (CBM) at the future Facility for Antiproton and Ion Research (FAIR). It enables high-precision low-momentum tracking in direct proximity of the target. Reaching the stringent requirements for the MVD, a material budget of~$0.3\,-\,0.5\%\,X_0$ per layer, operating the dedicated CMOS MAPS~(`MIMOSIS') in the target vacuum, the strong magnetic dipole field, and a harsh radiation environment~(5\,Mrad, $7\times10^{13}\,n_{\text{eq}}/\text{cm}^2$ per CBM year), poses an unprecedented integration challenge. In this paper, the integration concept of the detector is be outlined, elaborating on the selection and preparation of materials, assembly procedures, and quality assessment steps in the ongoing preparation of pre-series production and detector commissioning in 2028., Comment: Titlepage + 5 pages, 9 figures, proceedings for Pixel 2024

The geometry of electrodes is one of the most important factors in determining the performance of orthogonal-strip detectors. The aim of this work is to study the performance of a 5 mm thick cross-strip CdZnTe detector with different electrode widths. Our study consists of two main parts, simulations and experiments. We utilized four different anode sizes ranging from 0.1 mm to 0.6 mm. The anodes were interspersed with steering electrodes with varying sizes from 0.3 mm to 0.85 mm. The maximum gap size between the anodes and steering electrode strips was set to 0.3 mm, while the minimum gap size was 0.125 mm. The performance of the detector was investigated in terms of the steering electrode bias voltage, the energy resolution, and the charge sharing effect. For simulations, we developed a C++ based simulation program for charge transport inside the CdZnTe detector and charge collection at the electrodes. For photon interactions we used GEANT4 toolkit and for electric field and weighting potential simulations we used COMSOL software. The results demonstrated that -50 V is the optimal steering electrode bias for our detector when -500 V was applied to the cathodes and that the energy resolution performance drops with increasing steering electrode width. Also, the charge sharing effect becomes more dominant for larger steering electrode sizes. The experimental result are further compared with the simulations. The results are in a good agreement and the comparison validates our simulation model. Although, our simulation framework has need of better estimation for the intrinsic noise of CdZnTe. These results suggest that an optimization study between electrode widths and steering electrode bias is required to obtain the best performance in orthogonal-strip CdZnTe detectors.