@article {96, title = {Upgrade of ASACUSA{\textquoteright}s antihydrogen detector}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {1045}, year = {2023}, pages = {167568}, abstract = {The goal of the ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) CUSP experiment at CERN{\textquoteright}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.}, keywords = {Antihydrogen, antimatter, Data acquisition, Silicon photomultiplier}, issn = {0168-9002}, doi = {https://doi.org/10.1016/j.nima.2022.167568}, url = {https://www.sciencedirect.com/science/article/pii/S0168900222008609}, author = {V. Kraxberger and C. Amsler and H. Breuker and S. Chesnevskaya and G. Costantini and R. Ferragut and M. Giammarchi and A. Gligorova and G. Gosta and H. Higaki and E.D. Hunter and C. Killian and V. Kletzl and N. Kuroda and A. Lanz and M. Leali and V. M{\"a}ckel and G. Maero and C. Malbrunot and V. Mascagna and Y. Matsuda and S. Migliorati and D.J. Murtagh and Y. Nagata and A. Nanda and L. Nowak and E. Pasino and M. Rom{\'e} and M.C. Simon and M. Tajima and V. Toso and S. Ulmer and L. Venturelli and A. Weiser and E. Widmann and T. Wolz and Y. Yamazaki and J. Zmeskal} } @article {97, title = {Minimizing plasma temperature for antimatter mixing experiments}, journal = {EPJ Web Conf.}, volume = {262}, year = {2022}, pages = {01007}, doi = {10.1051/epjconf/202226201007}, url = {https://doi.org/10.1051/epjconf/202226201007}, author = {Hunter, E.D. and Amsler, C. and Breuker, H. and Chesnevskaya, S. and Costantini, G. and Ferragut, R. and Giammarchi, M. and Gligorova, A. and Gosta, G. and Higaki, H. and Kanai, Y. and Killian, C. and Kletzl, V. and Kraxberger, V. and Kuroda, N. and Lanz, A. and Leali, M. and M{\"a}ckel, V. and Maero, G. and Malbrunot, C. and Mascagna, V. and Matsuda, Y. and Migliorati, S. and Murtagh, D.J. and Nagata, Y. and Nanda, A. and Nowak, L. and Pasino, E. and Rom{\'e}, M. and Simon, M.C. and Tajima, M. and Toso, V. and Ulmer, S. and Uggerh\oj, U. and Venturelli, L. and Weiser, A. and Widmann, E. and Wolz, T. and Yamazaki, Y. and Zmeskal, J. and (The ASACUSA-Cusp Collaboration)} } @article {95, title = {Reducing the background temperature for cyclotron cooling in a cryogenic Penning{\textendash}Malmberg trap}, journal = {Physics of Plasmas}, volume = {29}, year = {2022}, month = {08}, pages = {083303}, abstract = {Magnetized nonneutral plasma composed of electrons or positrons couples to the local microwave environment via cyclotron radiation. The equilibrium plasma temperature depends on the microwave energy density near the cyclotron frequency. Fine copper meshes and cryogenic microwave absorbing material were used to lower the effective temperature of the radiation environment in ASACUSA{\textquoteright}s Cusp trap, resulting in significantly reduced plasma temperature.}, issn = {1070-664X}, doi = {10.1063/5.0093360}, url = {https://doi.org/10.1063/5.0093360}, author = {Amsler, C. and Breuker, H. and Chesnevskaya, S. and Costantini, G. and Ferragut, R. and Giammarchi, M. and Gligorova, A. and Gosta, G. and Higaki, H. and Hunter, E. D. and Killian, C. and Kletzl, V. and Kraxberger, V. and Kuroda, N. and Lanz, A. and Leali, M. and M{\"a}ckel, V. and Maero, G. and Malbrunot, C. and Mascagna, V. and Matsuda, Y. and Migliorati, S. and Murtagh, D. J. and Nagata, Y. and Nanda, A. and Nowak, L. and Pasino, E. and Rom{\'e}, M. and Simon, M. C. and Tajima, M. and Toso, V. and Ulmer, S. and Venturelli, L. and Weiser, A. and Widmann, E. and Wolz, T. and Yamazaki, Y. and Zmeskal, J.} } @article {91, title = {Hyperfine spectroscopy of hydrogen and antihydrogen in ASACUSA}, journal = {Hyperfine Interactions}, volume = {240}, year = {2018}, month = {Dec}, pages = {5}, abstract = {

The ASACUSA collaboration at the Antiproton Decelerator of CERN aims at a precise measurement of the antihydrogen ground-state hyperfine structure as a test of the fundamental CPT symmetry. A beam of antihydrogen atoms is formed in a CUSP trap, undergoes Rabi-type spectroscopy and is detected downstream in a dedicated antihydrogen detector. In parallel measurements using a polarized hydrogen beam are being performed to commission the spectroscopy apparatus and to perform measurements of parameters of the Standard Model Extension (SME). The current status of antihydrogen spectroscopy is reviewed and progress of ASACUSA is presented.

}, issn = {1572-9540}, doi = {10.1007/s10751-018-1536-9}, url = {https://doi.org/10.1007/s10751-018-1536-9}, author = {Widmann, E. and Amsler, C. and Arguedas Cuendis, S. and Breuker, H. and Diermaier, M. and Dupre, P. and Evans, C. and Fleck, M. and Gligorova, A. and Higaki, H. and Kanai, Y. and Kolbinger, B. and Kuroda, N. and Leali, M. and Leite, A. M. M. and M{\"a}ckel, V. and Malbrunot, C. and Mascagna, V. and Massiczek, O. and Matsuda, Y. and Murtagh, D. J. and Nagata, Y. and Nanda, A. and Phan, D. and Sauerzopf, C. and Simon, M. C. and Tajima, M. and Spitzer, H. and Strube, M. and Ulmer, S. and Venturelli, L. and Wiesinger, M. and Yamazaki, Y. and Zmeskal, J.} } @article {70, title = {The ASACUSA Micromegas Tracker: A cylindrical, bulk Micromegas detector for antimatter research}, journal = {Review of Scientific Instruments}, volume = {86}, year = {2015}, abstract = {

The ASACUSA Micromegas Tracker (AMT; ASACUSA: Atomic Spectroscopy and Collisions Using Slow Antiprotons) was designed to be able to reconstruct antiproton-nucleon annihilation vertices in three dimensions. The goal of this device is to study antihydrogen formation processes in the ASACUSA cusp trap, which was designed to synthesise a spin-polarised antihydrogen beam for precise tests of Charge, Parity, and Time (CPT) symmetry invariance. This paper discusses the structure and technical details of an AMT detector built into such an environment, its data acquisition system and the first performance with cosmic rays.

}, doi = {http://dx.doi.org/10.1063/1.4927685}, url = {http://scitation.aip.org/content/aip/journal/rsi/86/8/10.1063/1.4927685}, author = {Radics, B. and Nagata, Y. and Yamazaki, Y. and Ishikawa, S. and Kuroda, N. and Matsuda, Y. and Anfreville, M. and Aune, S. and Boyer, M. and Chateau, F. and Combet, M. and Granelli, R. and Legou, P. and Mandjavidze, I. and Procureur, S. and Riallot, M. and Vallage, B. and Vandenbroucke, M.} } @article {35, title = {Towards the production of anti-hydrogen beams}, journal = {AIP Conference Proceedings}, volume = {1521}, year = {2013}, pages = {134-143}, keywords = {antimatter, atomic beams, hydrogen neutral atoms, hyperfine structure, particle beam diagnostics}, doi = {10.1063/1.4796069}, url = {http://link.aip.org/link/?APC/1521/134/1}, author = {H. Higaki and Y. Enomoto and N. Kuroda and K. Michishio and D. J. Murtagh and S. Ulmer and S. Van Gorp and C. H. Kim and Y. Nagata and Y. Kanai and Torii, H.A. and M. Corradini and M. Leali and E. Lodi-Rizzini and V. Mascagna and L. Venturelli and N. Zurlo and K. Fujii and M. Otsuka and K. Tanaka and H. Imao and Y. Nagashima and Y. Matsuda and B. Juh{\'a}sz and A. Mohri and Y. Yamazaki}, editor = {Xabier Sarasola and Lutz Schweikhard and Thomas Sunn Pedersen} } @article {24, title = {Radial compression of antiproton cloud for production of ultraslow antiproton beams}, journal = {AIP Conference Proceedings}, volume = {1114}, year = {2009}, pages = {157-162}, keywords = {particle traps, plasma, plasma simulation}, doi = {10.1063/1.3122278}, url = {http://link.aip.org/link/?APC/1114/157/1}, author = {N. Kuroda and Y. Nagata and H. A. Torii and D. Barna and J. Eades and D. Horv{\'a}th and M. Hori and H. Imao and K. Komaki and A. Mohri and M. Shibata and Y. Yamazaki}, editor = {James R. Danielson and Thomas Sunn Pedersen} } @article {15, title = {Cooling by Spontaneous Decay of Highly Excited Antihydrogen Atoms in Magnetic Traps}, journal = {Physical Review LettersPhys. Rev. Lett.}, volume = {97}, year = {2006}, month = {2006/11/22/}, pages = {213001 -}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.97.213001}, author = {Pohl, T. and Sadeghpour, H. R. and Nagata, Y. and Yamazaki, Y.} }