000004369 001__ 4369
000004369 005__ 20240604090511.0
000004369 037__ $$aBELLE2-TALK-CONF-2024-074
000004369 041__ $$aeng
000004369 100__ $$aGiuliana Rizzo, INFN and University, Pisa 
000004369 245__ $$aThe DMAPS upgrade of the Belle II Vertex Detector
000004369 260__ $$a 16th Pisa Meeting on Advanced Detectors$$c2024-05-28
000004369 300__ $$amult. p
000004369 500__ $$a17+3
000004369 520__ $$aAbstract: The SuperKEKB collider will undergo a major upgrade at the end of the decade to reach the target luminosity of 6 10^35 cm-2 s-1, offering the opportunity to install a new pixelated vertex detector (VTX) for the Belle II experiment. The VTX will be more robust against the expected higher level of machine background and more performant in terms of standalone track finding efficiency. The VTX design matches the modified interaction region and includes five layers, spanning radii from 14 mm to 135 mm. All layers are equipped with the same depleted-MAPS, OBELIX, designed in the Tower 180 nm technology, which pixel matrix is derived from the TJ-Monopix2 sensor originally developed for the ATLAS experiment. Featuring a 33 µm pitch, OBELIX integrates hits over 100 ns while dissipating less than 200 mW/cm2 at an average hit rate of 60 MHz/cm2. The digital trigger logic matches the 30 kHz average Belle II trigger rate with 10 µs trigger delay and a maximum hit rate of 120 MHz/cm2. The two innermost layers (iVTX) have a sensitive length of about 12 cm and aim for a material budget below 0.2 % X0/layer, benefitting from air cooling. One ladder is made of a 4-sensor wide module cut out from processed wafers and submitted to post-processing operations in order to connect them at one end. The three outer layers (oVTX) target material budget ranging from 0.3 % X0 for the shortest length up to 0.8 % X0 for the 70 cm-long and outermost layer. The ladder concept uses a light mechanical structure supporting a liquid-cooled plate in contact with the sensors connected to a flex printed cable. We will review all project aspects: tests of the TJ-Monopix2 sensor, OBELIX-1 design status, prototype fabrication and tests for the iVTX and oVTX concepts, including their cooling.
000004369 6531_ $$aupgrade
000004369 6531_ $$aVXD
000004369 6531_ $$aVTX
000004369 6531_ $$aCMOS
000004369 6531_ $$aMAPS
000004369 6531_ $$aDMAPS
000004369 6531_ $$avertex
000004369 6531_ $$avertex detector
000004369 700__ $$aBelle II VTX Upgrade Group
000004369 8560_ $$fgiuliana.rizzo@pi.infn.it
000004369 8564_ $$uhttps://docs.belle2.org/record/4369/files/BELLE2-TALK-CONF-2024-074.pdf