Upgrade of ASACUSA's antihydrogen detector

Autor(en)

V. Kraxberger, C. Amsler, H. Breuker, S. Chesnevskaya, G. Costantini, R. Ferragut, M. Giammarchi, A. Gligorova, G. Gosta, H. Higaki, E. D. Hunter, C. Killian, V. Kletzl, N. Kuroda, A. Lanz, M. Leali, V. Mäckel, G. Maero, C. Malbrunot, V. Mascagna, Y. Matsuda, S. Migliorati, D. J. Murtagh, Y. Nagata, A. Nanda, L. Nowak, E. Pasino, M. Romé, M. C. Simon, M. Tajima, V. Toso, S. Ulmer, L. Venturelli, A. Weiser, E. Widmann, T. Wolz, Y. Yamazaki, J. Zmeskal

Abstrakt

The goal of the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) CUSP experiment at CERN's Antiproton Decelerator is to measure the ground state hyperfine splitting of antihydrogen in order to test whether CPT invariance is broken. The ASACUSA hodoscope is a detector consisting of two layers of 32 plastic scintillator bars individually read out by two serially connected silicon photomultipliers (SiPMs) on each end. Two additional layers for position resolution along the beam axis were scintillator fibres, which will now be replaced by scintillating tiles placed onto the existing bars and also read out by SiPMs. If the antiproton of antihydrogen annihilates in the centre of the hodoscope, particles (mostly pions) are produced and travel through the various layers of the detector and produce signals. The hodoscope was successfully used during the last data taking period at CERN. The necessary time resolution to discriminate between particles travelling through the detector from outside and particles produced in the centre of the detector was achieved by the use of waveform digitisers and software constant fraction discrimination. The disadvantage of this readout scheme was the slow readout speed, which was improved by two orders of magnitude. This was done by omitting the digitisers and replacing them with TDCs reading out the digital time-over-threshold (ToT) signal using leading edge discrimination.

Organisation(en)

Fakultät für Physik

Externe Organisation(en)

Österreichische Akademie der Wissenschaften (ÖAW), RIKEN, Università degli Studi di Brescia, Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pavia, Politecnico di Milano, Istituto Nazionale di Fisica Nucleare (INFN), Milano, Hiroshima University, University of Tokyo, Università degli Studi di Milano-Bicocca, European Organization for Nuclear Research (CERN), Tokyo University of Science

Journal

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Band

1045

Anzahl der Seiten

3

ISSN

0168-9002

DOI

https://doi.org/10.1016/j.nima.2022.167568

Publikationsdatum

01-2023

Peer-reviewed

Ja

ÖFOS 2012

103014 Kernphysik

Schlagwörter

ASJC Scopus Sachgebiete

Nuclear and High Energy Physics, Instrumentation

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/3c5caf67-e12e-42c9-a69c-a8af52cb5aa9