https://doi.org/10.1140/epjc/s10052-021-09769-3
Special Article - Tools for Experiment and Theory
A time resolved study of injection backgrounds during the first commissioning phase of SuperKEKB
1
Max-Planck-Institut für Physik, 80805, Munich, Germany
2
High Energy Accelerator Research Organization (KEK), 305-0801, Tsukuba, Japan
3
University of Hawaii, 96822, Honolulu, HI, USA
4
INFN Laboratori Nazionali di Frascati, 00044, Frascati, Italy
5
Purdue University, 47907, West Lafayette, IN, USA
6
Thomas Jefferson National Accelerator Facility, 23606, Newport News, VA, USA
7
The Hague University of Applied Sciences, The Hague, Netherlands
8
University of Bonn, 53115, Bonn, Germany
9
Google LLC., 93101, Santa Barbara, CA, USA
Received:
22
December
2020
Accepted:
25
October
2021
Published online:
5
November
2021
We report on measurements of beam backgrounds during the first commissioning phase of the SuperKEKB collider in 2016, performed with the plastic scintillator and silicon photomultiplier-based CLAWS detector system. The sub-nanosecond time resolution and single particle detection capability of the sensors allow bunch-by-bunch measurements, enable CLAWS to perform a novel time resolved analysis of beam backgrounds, and make the system uniquely suited for the study of injection backgrounds. We present measurements of various aspects of regular beam background and injection backgrounds which include time structure and decay behavior of injection backgrounds, hit-energy spectra and overall background rates. These measurements show that the elevated background rates following an injection generally last for several milliseconds, with the majority of the background particles typically observed within the first 
. The injection backgrounds exhibit pronounced patterns in time, connected to betatron and synchrotron oscillations in the accelerator rings. The frequencies of these patterns are determined from detector data.
© The Author(s) 2021
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