Measurements of Beam Backgrounds in SuperKEKB Phase 2
Abstract
The high design luminosity of the SuperKEKB electron-positron collider will result in challenging levels of beam-induced backgro\ unds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of the Belle~II experi\ ment. We report on the first background measurements performed after roll-in of the Belle II detector, a period known as SuperKE\ KB Phase 2, utilizing both the BEAST II system of dedicated background detectors and the Belle II detector itself. We also repor\ t on first revisions to the background simulation made in response to our findings. Backgrounds measured include contributions f\ rom synchrotron radiation, beam-gas, Touschek, and injection backgrounds. At the end of Phase 2, single-beam backgrounds origina\ ting from the 4 GeV positron Low Energy Ring (LER) agree reasonably well with simulation, while backgrounds from the 7 GeV elect\ ron High Energy Ring (HER) are approximately one order of magnitude higher than simulation. We extrapolate these backgrounds for\ ward and conclude it is safe to install the Belle II vertex detector.
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Cite
@article{arxiv.2112.14537,
title = {Measurements of Beam Backgrounds in SuperKEKB Phase 2},
author = {Zachary J. Liptak and Antonio Paladino and Luka Santelj and Jeffery Schueler and Slavomira Stefkova and Hikaru Tanigawa and Noritsugu Tsuzuki and Alberto Aloisio and Patrick Ahlburg and Philip Bambade and Giovanni Bassi and Matthew Barrett and Jerome Baudot and Thomas Browder and Giulia Casarosa and Giuseppe Cautero and David Cinabro and Gilles Claus and Daniel Cuesta and Francesco Di Capua and Salvatore Di Carlo and John Flanagan and Ariane Frey and Bryan Fulsom and Yoshihiro Funakoshi and Miroslav Gabriel and Raffaele Girodano and Dario Giuressi and Mathieu Goffe and Koji Hara and Oskar Hartbrich and Michael Hedges and Daniel Heuchel and Naoko Iida and Takuya Ishibashi and Kimmo Jaaskelainen and Didier Jehanno and Samuel de Johng and Thomas Kraetzschmar and Chiara la Licata and Livio Lanceri and Philipp Leitl and Peter Lewis and Carlos Marinas and Caleb Miller and Katsuro Nakamura and Hiroyuki Nakayama and Carsten Niebuhr and Yoshiyuki Onuki and Chengguo Pang and Botho Paschen and Isabelle Ripp-Baudot and Giuliana Rizzo and J. Michael Roney and Harrison Schreeck and Benjamin Schwenker and Frank Simon and Matthieu Specht and Bjoern Spruck and Yuri Soloviev and Michal Szelezniak and Shuji Tanaka and Shinji Terui and Gennaro Tortone and Tohru Tsuboyama and Yuma Uematsu and Sven Einar Vahsen and Lorenzo Vitale and Hendrik Windel},
journal= {arXiv preprint arXiv:2112.14537},
year = {2022}
}
Comments
22 Pages, 33 figures