Year: 2023
Type: conference-paper
Abstract: The Belle II experiment at the super KEK B-factory (SuperKEKB) in Tsukuba, Japan, has been collecting $e^+e^-$ collision data since March 2019. Operating at a record-breaking luminosity of up to $4.7\times10^{34} \ cm^{-2}s^{-1}$, data corresponding to $424 \ fb^{-1}$ has since been recorded. The Belle II VerteX Detector (VXD) is central to the Belle II detector and its physics program and plays a crucial role in reconstructing precise primary and decay vertices. It consists of the outer 4-layer Silicon Vertex Detector (SVD) using double sided silicon strips and the inner two-layer PiXel Detector (PXD) based on the Depleted P-channel Field Effect Transistor (DePFET) technology. The PXD DePFET structure combines signal generation and amplification within pixels with a minimum pitch of $(50 \times 55) \ μm^2$. A high gain and a high signal-to-noise ratio allow thinning the pixels to $75 \ μm$ while retaining a high pixel hit efficiency of about $99 \%$. As a consequence, also the material budget of the full detector is kept low at $\approx 0.21\% \frac{X}{X_0}$ per layer in the acceptance region. This also includes contributions from the control, Analog-to-Digital Converter (ADC), and data processing Application Specific Integrated Circuits (ASICs) as well as from cooling and support structures. This article will present the experience gained from four years of operating PXD; the first full scale detector employing the DePFET technology in High Energy Physics. Overall, the PXD has met the expectations. Operating in the intense SuperKEKB environment poses many challenges that will also be discussed. The current PXD system remains incomplete with only 20 out of 40 modules having been installed. A full replacement has been constructed and is currently in its final testing stage before it will be installed into Belle II during the ongoing long shutdown that will last throughout 2023.
DOI: 10.22323/1.420.0005
Authors: Georgios Giakoustidis, Fernando Abudinen, Karlheinz Ackermann, Patrick Ahlburg, Mohammed Albalawi, Oscar Alonso, Laci Andricek, Rachid Ayad, Varghese Babu, Anselm Baur, Florian Bernlochner, Tadeas Bilka, Arthur Bolz, Andrzej Bozek, Christian Camien, Allen Christopher Caldwell, Lu Cao, Vladimir Chekelian, Angel Dieguez, Jochen Christian Dingfelder, Zdenek Dolezal, Markus Fras, Ariane Frey, Miroslav Gabriel, Karsten Gadow, Thomas Gessler, Dennis Getzkow, Luigi Li Gioi, Daniel Greenwald, Martin Heck, Martin Hensel, Matthias Hoek, Stefan Huber, Jakub Kandra, Pjotr Kapusta, Robert Karl, Jasper Kehl, Christian Kiesling, Bartlomiej Kisielewski, David Kittlinger, Daniel Klose, Peter Kodys, Christian Koffmane, Igor Konorov, Matthäus Krein, Silvia Krivokuca, Thomas Kuhr, Simon Kurz, Peter Kvasnicka, Jens Sören Lange, Klemens Lautenbach, Ullrich Leis, Philipp Leitl, Dmytro Levit, Gerhard Liemann, Qingyuan Liu, Zhen’An Liu, Thomas Lück, Carlos Marinas, Sara Mccarney, Hans-Günther Moser, David Moya, Felix Johannes Müller, Felix Müller, Carsten Niebuhr, Jelena Ninkovic, Botho Paschen, Stephan Paul, Ivan Peric, Daniel Pitzl, Andrei Rabusov, Markus Reif, Simon Patrik Reiter, Rainer Richter, Martin Ritter, Michael Ritzert, Javier Gonzalez Sanchez, Bianca Scavino, Gerhard Schaller, Jannes Schmitz, Martina Schnecke, Florian Schopper, Harrison Schreeck, Benjamin Schwenker, Marike Schwickardi, Reinhard Sedlmeyer, Concettina Sfienti, Frank Simon, Sebastian Skambraks, Justin Skorupa, Yuri Soloviev, Björn Spruck, Slavomira Stefkova, Reimer Stever, Eva Tafelmayer, Maiko Takahashi, Ivan Vila Álvarez, Amparo Lopez Virto, Sven Vogt, Chunjie Wang, Philipp Wieduwilt, Hendrik Windel, Hua Ye, Jingzhou Zhao, Radek Zlebcik
Institutions: Johannes Gutenberg University Mainz, Charles University, Max Planck Institute for Physics, Instituto de Física de Cantabria, Halbleiterlabor of the Max-Planck-Society, Technical University of Munich, Universitat de Barcelona, Ludwig-Maximilians-Universität München, Consejo Superior de Investigaciones Científicas, University of Tabuk, Karlsruhe Institute of Technology, University of Bonn, Chinese Academy of Sciences, Justus-Liebig-Universität Gießen, Heidelberg University, Deutsches Elektronen-Synchrotron DESY, Institute of Nuclear Physics, Polish Academy of Sciences, Institute of High Energy Physics, University of Göttingen
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
OpenAlex ID: W4324096906