@article {98, title = {SDR, EVC, and SDREVC: Limitations and Extensions}, journal = {Journal of Plasma Physics}, volume = {89}, year = {2023}, pages = {955890501}, doi = {10.1017/S0022377823001022}, author = {Hunter, E.D. and Amsler, C. and Breuker, H. and Bumbar, M. and Chesnevskaya, S. and Costantini, G. and Ferragut, R. and Giammarchi, M. and Gligorova, A. and Gosta, G. and Higaki, H. and Killian, C. and Kraxberger, V. and Kuroda, N. and Lanz, A. and Leali, M. and Maero, G. and Malbrunot, C. and Mascagna, V. and Matsuda, Y. and M{\"a}ckel, V. and Migliorati, S. and Murtagh, D.J. and Nanda, A. and Nowak, L. and Parnefjord Gustafsson, F. and Rheinfrank, S. and Rom{\'e}, M. and Simon, M.C. and Tajima, M. and Toso, V. and Ulmer, S. and Ventrurelli, L. and Weiser, A. and Widmann, E. and Yamazaki, Y. and Zmeskal, J. and The ASACUSA-Cusp Collaboration} } @article {99, title = {Slow positron production and storage for the ASACUSA-Cusp experiment}, journal = {Journal of Plasma Physics}, volume = {89}, year = {2023}, pages = {905890608}, doi = {10.1017/S0022377823001034}, author = {Murtagh, D.J. and Amsler, C. and Breuker, H. and Bumbar, M. 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 Kraxberger, V. and Kuroda, N. and Lanz, A. and Leali, M. and Maero, G. and Malbrunot, C. and Mascagna, V. and Matsuda, Y. and M{\"a}ckel, V. and Migliorati, S. and Nanda, A. and Nowak, L. and Parnefjord Gustafsson, F. and Rheinfrank, S. 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 {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 {94, title = {Measurement of the principal quantum number distribution in a beam of antihydrogen atoms}, volume = {75}, year = {2021}, month = {2021/03/08}, pages = {91}, abstract = {The ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) collaboration plans to measure the ground-state hyperfine splitting of antihydrogen in a beam at the CERN Antiproton Decelerator with initial relative precision of $$10^{-6}$$or better, to test the fundamental CPT (combination of charge conjugation, parity transformation and time reversal) symmetry between matter and antimatter. This challenging goal requires a polarised antihydrogen beam with a sufficient number of antihydrogen atoms in the ground state. The first measurement of the quantum state distribution of antihydrogen atoms in a low magnetic field environment of a few mT is described. Furthermore, the data-driven machine learning analysis to identify antihydrogen events is discussed.}, isbn = {1434-6079}, url = {https://doi.org/10.1140/epjd/s10053-021-00101-y}, author = {Kolbinger, B. and Amsler, C. and Cuendis, S. Arguedas and Breuker, H. and Capon, A. and Costantini, G. and Dupre, P. and Fleck, M. and Gligorova, A. and Higaki, H. and Kanai, Y. and Kletzl, V. and Kuroda, N. and Lanz, A. and Leali, 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 Nowak, L. and Radics, B. and Sauerzopf, C. and Simon, M. C. and Tajima, M. and Torii, H. A. and Uggerh{\o}j, U. and Ulmer, S. and Venturelli, L. and Weiser, A. and Wiesinger, M. and Widmann, E. and Wolz, T. and Yamazaki, Y. and Zmeskal, J.} } @article {92, title = {Antiproton beams with low energy spread for antihydrogen production}, journal = {Journal of Instrumentation}, volume = {14}, year = {2019}, month = {05/2019}, pages = {P05009{\textendash}P05009}, abstract = {

A low energy antiproton transport from the ASACUSA{\textquoteright}s antiproton accumulation trap (MUSASHI trap) to the antihydrogen production trap (double cusp trap) is developed. The longitudinal antiproton energy spread after the transport line is 0.23{\textpm}0.02 eV, compared with 15 eV with a previous method used in 2012. This reduction is achieved by an adiabatic transport beamline with several pulse-driven coaxial coils. Antihydrogen atoms are synthesized by directly injecting the antiprotons into a positron plasma, resulting in the higher production rate.

}, doi = {10.1088/1748-0221/14/05/p05009}, url = {https://doi.org/10.1088\%2F1748-0221\%2F14\%2F05\%2Fp05009}, author = {M. Tajima and N. Kuroda and C. Amsler and H. Breuker and C. Evans and M. Fleck and A. Gligorova and H. Higaki and Y. Kanai and B. Kolbinger and A. Lanz and M. Leali and V. M{\"a}ckel and C. Malbrunot and V. Mascagna and Y. Matsuda and D. Murtagh and Y. Nagata and A. Nanda and B. Radics and M. Simon and S. Ulmer and L. Venturelli and E. Widmann and M. Wiesinger and Y. Yamazaki} } @article {88, title = {The ASACUSA antihydrogen and hydrogen program: results and prospects}, journal = {Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences}, volume = {376}, year = {2018}, abstract = {The goal of the ASACUSA-CUSP collaboration at the Antiproton Decelerator of CERN is to measure the ground-state hyperfine splitting of antihydrogen using an atomic spectroscopy beamline. A milestone was achieved in 2012 through the detection of 80 antihydrogen atoms 2.7 m away from their production region. This was the first observation of {\textquoteleft}cold{\textquoteright} antihydrogen in a magnetic field free region. In parallel to the progress on the antihydrogen production, the spectroscopy beamline was tested with a source of hydrogen. This led to a measurement at a relative precision of 2.7{\texttimes}10-9 which constitutes the most precise measurement of the hydrogen hyperfine splitting in a beam. Further measurements with an upgraded hydrogen apparatus are motivated by CPT and Lorentz violation tests in the framework of the Standard Model Extension. Unlike for hydrogen, the antihydrogen experiment is complicated by the difficulty of synthesizing enough cold antiatoms in the ground state. The first antihydrogen quantum states scan at the entrance of the spectroscopy apparatus was realized in 2016 and is presented here. The prospects for a ppm measurement are also discussed.This article is part of the Theo Murphy meeting issue {\textquoteleft}Antiproton physics in the ELENA era{\textquoteright}.}, issn = {1364-503X}, doi = {10.1098/rsta.2017.0273}, url = {http://rsta.royalsocietypublishing.org/content/376/2116/20170273}, author = {Malbrunot, C. and Amsler, C. and Arguedas Cuendis, S. and Breuker, H. and Dupre, P. and Fleck, M. and Higaki, H. and Kanai, Y. and Kolbinger, B. and Kuroda, N. and Leali, M. and M{\"a}ckel, V. and Mascagna, V. and Massiczek, O. and Matsuda, Y. and Nagata, Y. and Simon, M. C. and Spitzer, H. and Tajima, M. and Ulmer, S. and Venturelli, L. and Widmann, E. and Wiesinger, M. 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 {93, title = {Recent Developments from ASACUSA on Antihydrogen Detection}, journal = {EPJ Web of Conferences}, volume = {181}, year = {2018}, pages = {01003}, doi = {10.1051/epjconf/201818101003}, url = {https://doi.org/10.1051/epjconf/201818101003}, author = {Kolbinger, B. and Amsler, C. and Breuker, H. and Diermaier, M. and Dupre, P. and Fleck, M. and Gligorova, A. and Higaki, H. and Kanai, Y. and Kobayashi, T. and Leali, 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 Sauerzopf, C. and Simon, M.C. and Tajima, M. and Ulmer, S. and Kuroda, N. and Venturelli, L. and Widmann, E. and Yamazaki, Y. and Zmeskal, J.} } @article {78, title = {Antihydrogen synthesis in a double-CUSP trap towards test of the CPT-symmetry}, journal = {Hyperfine Interactions}, volume = {237}, year = {2016}, pages = {156}, abstract = {

The aim of the ASACUSA-CUSP experiment at CERN is to produce a cold, polarised antihydrogen beam and perform a high precision measurement of the ground-state hyperfine transition frequency of the antihydrogen atom and compare it with that of the hydrogen atom using the same spectroscopic beam line. Towards this goal a significant step was successfully accomplished: synthesised antihydrogen atoms have been produced in a CUSP magnetic configuration and detected at the end of our spectrometer beam line in 2012 [1]. During a long shut down at CERN the ASACUSA-CUSP experiment had been renewed by introducing a new double-CUSP magnetic configuration and a new semi-cylindrical tracking detector (AMT) [2], and by improving the transport feature of low energy antiproton beams. The new tracking detector monitors the antihydrogen synthesis during the mixing cycle of antiprotons and positrons. In this work the latest results and improvements of the antihydrogen synthesis will be presented including highlights from the last beam time.

}, issn = {1572-9540}, doi = {10.1007/s10751-016-1368-4}, url = {http://dx.doi.org/10.1007/s10751-016-1368-4}, author = {Radics, B. and Ishikawa, S. and Kuroda, N. and Murtagh, D. J. and Nagata, Y. and Tajima, M. and Van Gorp, S. and Abo, Y. and Dupre, P. and Higashi, Y. and Kaga, C. and Leali, M. and Mascagna, V. and Venturelli, L. and Zurlo, N. and Breuker, H. and Higaki, H. and Kanai, Y. and Rizzini, E. Lodi and Matsuda, Y. and Ulmer, S. and Yamazaki, Y.} } @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 {20, title = {On the double ionization of helium by very slow antiproton impact}, journal = {Proceedings of the Fourth International Conference on Elementary Processes in Atomic Systems}, volume = {267}, year = {2009}, month = {2009/1//}, pages = {244 - 247}, keywords = {Antiproton, CERN AD, Electron correlation, Ionization}, isbn = {0168-583X}, url = {http://www.sciencedirect.com/science/article/pii/S0168583X08011373}, author = {Knudsen, H. and Kristiansen, H.-P. E. and Thomsen, H. D. and Uggerh{\o}j, U. I. and Ichioka, T. and M{\o}ller, S. P. and Hunniford, C. A. and McCullough, R. W. and Charlton, M. and Kuroda, N. and Nagata, Y. and Torii, H. A. and Yamazaki, Y. and Imao, H. and Andersen, H. H. and T{\"o}kesi, K.} } @article {19, title = {Ionization of Helium and Argon by Very Slow Antiproton Impact}, journal = {Physical Review LettersPhys. Rev. Lett.}, volume = {101}, year = {2008}, month = {2008/07/25/}, pages = {043201 -}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.101.043201}, author = {Knudsen, H. and Kristiansen, H.-P. E. and Thomsen, H. D. and Uggerh{\o}j, U. I. and Ichioka, T. and M{\o}ller, S. P. and Hunniford, C. A. and McCullough, R. W. and Charlton, M. and Kuroda, N. and Nagata, Y. and Torii, H. A. and Yamazaki, Y. and Imao, H. and Andersen, H. H. and T{\"o}kesi, K.} }