The Belle II silicon vertex detector assembly and mechanics

The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules.Finally, some results from the latest test-beam are reported

The Belle II SVD data readout system

The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the standard model.172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC).Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network.We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing

The Design, Construction, Operation and Performance of the Belle II Silicon Vertex Detector

The Silicon Vertex Detector of Belle II is a state-of-the-art tracking an vertexing system based on double-sided silicon strip sensors, designed and fabricated by a large international collaboration in the period 2012--2018. Since 2019 it has been in operation providing high quality data with a small number of defective channels (99%), a good signal-to-noise ratio (well in excess of 10 for all sensor configurations and tracks). Toghether with the good control over the alignment, these are all essential factors to achieve good tracking reconstruction and physics performance. In this extended paper we try to document all the aspects of the SVD challenges and achievements, in the spirit of providing information to the broader community and help the development of high quality detector systems, which are fundamental tools to carry out physics research

The Design, Construction, Operation and Performance of the Belle II Silicon Vertex Detector

The Silicon Vertex Detector of Belle II is a state-of-the-art tracking an vertexing system based on double-sided silicon strip sensors, designed and fabricated by a large international collaboration in the period 2012--2018. Since 2019 it has been in operation providing high quality data with a small number of defective channels (99%), a good signal-to-noise ratio (well in excess of 10 for all sensor configurations and tracks). Toghether with the good control over the alignment, these are all essential factors to achieve good tracking reconstruction and physics performance. In this extended paper we try to document all the aspects of the SVD challenges and achievements, in the spirit of providing information to the broader community and help the development of high quality detector systems, which are fundamental tools to carry out physics research