@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 {90, title = {Monte-Carlo based performance assessment of ASACUSA{\textquoteright}s antihydrogen detector}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {910}, year = {2018}, pages = {90 - 95}, abstract = {

An antihydrogen detector consisting of a thin BGO disk and a surrounding plastic scintillator hodoscope has been developed. We have characterized the two-dimensional positions sensitivity of the thin BGO disk and energy deposition into the BGO was calibrated using cosmic rays by comparing experimental data with Monte-Carlo simulations. The particle tracks were defined by connecting BGO hit positions and hits on the surrounding hodoscope scintillator bars. The event rate was investigated as a function of the angles between the tracks and the energy deposition in the BGO for simulated antiproton events, and for measured and simulated cosmic ray events. Identification of the antihydrogen Monte Carlo events was performed using the energy deposited in the BGO and the particle tracks. The cosmic ray background was limited to 12\ mHz with a detection efficiency of 81\%. The signal-to-noise ratio was improved from 0.22\ s-1/2 obtained with the detector in 2012 to 0.26\ s-1/2 in this work.

}, keywords = {Antihydrogen, antimatter, Calorimeter, Detector, Tracker}, issn = {0168-9002}, doi = {10.1016/j.nima.2018.09.013}, url = {http://www.sciencedirect.com/science/article/pii/S0168900218311227}, author = {Y. Nagata and N. Kuroda and B. Kolbinger and M. Fleck and C. Malbrunot and V. M{\"a}ckel and C. Sauerzopf and M.C. Simon and M. Tajima and J. Zmeskal and H. Breuker and H. Higaki and Y. Kanai and Y. Matsuda and S. Ulmer and L. Venturelli and E. Widmann and Y. Yamazaki} } @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 {87, title = {The Development of the Antihydrogen Beam Detector: Toward the Three Dimensional Tracking with a BGO Crystal and a Hodoscope}, journal = {JPS Conf. Proc.}, volume = {18}, year = {2017}, pages = {011038}, doi = {10.7566/JPSCP.18.011038}, author = {Y. Nagata and N. Kuroda and C. Sauerzopf and B. Kolbinger and C. Malbrunot and A. A. Capon and P. Dupre and B. Radics and M. Tajima and C. Kaga and M. Leali and E. Lodi Rizzini and V. Mascagna and O. Massiczek and T. Matsudate and M. C. Simon and H. Breuker and H. Higaki and Y. Kanai and Y. Matsuda and L. Venturelli and E. Widmann and Y. Yamazaki} } @article {86, title = {Efficient antihydrogen detection in antimatter physics by deep learning}, journal = {Journal of Physics Communications}, volume = {1}, year = {2017}, pages = {025001}, abstract = {Antihydrogen is at the forefront of antimatter research at the CERN Antiproton Decelerator. Experiments aiming to test the fundamental CPT symmetry and antigravity effects require the efficient detection of antihydrogen annihilation events, which is performed using highly granular tracking detectors installed around an antimatter trap. Improving the efficiency of the antihydrogen annihilation detection plays a central role in the final sensitivity of the experiments. We propose deep learning as a novel technique to analyze antihydrogen annihilation data, and compare its performance with a traditional track and vertex reconstruction method. We report that the deep learning approach yields significant improvement, tripling event coverage while simultaneously improving performance in terms of AUC by 5\%.}, url = {http://stacks.iop.org/2399-6528/1/i=2/a=025001}, author = {P Sadowski and B Radics and Ananya and Y Yamazaki and P Baldi} } @article {79, title = {In-beam measurement of the hydrogen hyperfine splitting - towards antihydrogen spectroscopy}, journal = {Nature Communications}, volume = {8}, year = {2017}, month = {12/06/2017}, pages = {1{\textendash}9}, abstract = {

Antihydrogen, the lightest atom consisting purely of antimatter, is an ideal laboratory to study the CPT symmetry by comparison to hydrogen. With respect to absolute precision, transitions within the ground-state hyperfine structure (GS-HFS) are most appealing by virtue of their small energy separation. ASACUSA proposed employing a beam of cold antihydrogen atoms in a Rabi-type experiment to determine the GS-HFS in a field-free region. Here we present a measurement of the zero-field hydrogen GS-HFS using the spectroscopy apparatus of ASACUSA{\textquoteright}s antihydrogen experiment. The measured value of {\$}\backslashnu{\_}\backslashmathrm{\{}HF{\}}{\$}={\$}1{\~{}}420{\~{}}405{\~{}}748.4(3.4)(1.6){\~{}}\backslashtextrm{\{}Hz{\}}{\$} with a relative precision of {\$}\backslashDelta{\$}{\$}\backslashnu{\_}\backslashmathrm{\{}HF{\}}{\$}/{\$}\backslashnu{\_}\backslashmathrm{\{}HF{\}}{\$}={\$}2.7\backslashtimes10{\^{}}{\{}-9{\}}{\$} constitutes the most precise determination of this quantity in a beam and verifies the developed spectroscopy methods for the antihydrogen HFS experiment to the ppb level. Together with the recently presented observation of antihydrogen atoms {\$}2.7{\~{}}\backslashtextrm{\{}m{\}}{\$} downstream of the production region, the prerequisites for a measurement with antihydrogen are now available within the ASACUSA collaboration.

}, doi = {10.1038/ncomms15749}, url = {https://doi.org/10.1038/ncomms15749}, author = {Diermaier, M. and Jepsen, C. B. and Kolbinger, B. and Malbrunot, C. and Massiczek, O. and Sauerzopf, C. and Simon, M. C. and Zmeskal, J. and Widmann, E.} } @article {81, title = {Progress of Antihydrogen Beam Production Using a Double Cusp Trap}, journal = {JPS Conf. Proc.}, volume = {18}, year = {2017}, pages = {011007}, doi = {10.7566/JPSCP.18.011007}, author = {Y. Nagata and N. Kuroda and P. Dupre and B. Radics and M. Tajima and A. A. Capon and M. Diermaier and C. Kaga and B. Kolbinger and M. Leali and E. Lodi Rizzini and C. Malbrunot and V. Mascagna and O. Massiczek and T. Matsudate and C. Sauerzopf and M. C. Simon and K. Suzuki and J. Zmeskal and H. Breuker and H. Higaki and Y. Kanai and Y. Matsuda and S. Ulmer and L. Venturelli and E. Widmann and Y. Yamazaki} } @article {77, title = {Annihilation detector for an in-beam spectroscopy apparatus to measure the ground state hyperfine splitting of antihydrogen}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, year = {2016}, pages = {-}, keywords = {Silicon photomultiplier}, issn = {0168-9002}, doi = {http://dx.doi.org/10.1016/j.nima.2016.06.023}, url = {http://www.sciencedirect.com/science/article/pii/S0168900216305630}, author = {Clemens Sauerzopf and Aaron A. Capon and Martin Diermaier and Markus Fleck and Bernadette Kolbinger and Chlo{\'e} Malbrunot and Oswald Massiczek and Martin C. Simon and Stefan Vamosi and Johann Zmeskal and Eberhard Widmann} } @article {74, title = {Intelligent Front-end Electronics for Silicon photodetectors (IFES)}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {819}, year = {2016}, pages = {163 - 166}, abstract = {Abstract While high channel density can be easily achieved for big experiments using custom made microchips, providing something similar for small and medium size experiments imposes a challenge. Within this work we describe a novel and cost effective solution to operate silicon photodetectors such as silicon photo multipliers (SiPM). The {\.I}FES\} modules provide the bias voltage for the detectors, a leading edge discriminator featuring time over threshold and a differential amplifier, all on one printed circuit board. We demonstrate under realistic conditions that the module is usable for high resolution timing measurements exploiting both charge and time information. Furthermore we show that the modules can be easily used in larger detector arrays. All in all this confirms that the {\.I}FES\} modules are a viable option for a broad range of experiments if cost-effectiveness and small form factor are required.}, keywords = {Silicon photomultiplier}, issn = {0168-9002}, doi = {http://dx.doi.org/10.1016/j.nima.2016.02.098}, url = {http://www.sciencedirect.com/science/article/pii/S0168900216300158}, author = {Clemens Sauerzopf and Lukas Gruber and Ken Suzuki and Johann Zmeskal and Eberhard Widmann} } @article {80, title = {Towards measuring the ground state hyperfine splitting of antihydrogen {\textendash} a progress report}, journal = {Hyperfine Interactions}, volume = {237}, year = {2016}, month = {Jun}, pages = {103}, abstract = {We report the successful commissioning and testing of a dedicated field-ioniser chamber for measuring principal quantum number distributions in antihydrogen as part of the ASACUSA hyperfine spectroscopy apparatus. The new chamber is combined with a beam normalisation detector that consists of plastic scintillators and a retractable passivated implanted planar silicon (PIPS) detector.}, issn = {1572-9540}, doi = {10.1007/s10751-016-1309-2}, url = {https://doi.org/10.1007/s10751-016-1309-2}, author = {Sauerzopf, C. and Capon, A. A. and Diermaier, M. and Dupre, P. and Higashi, Y. and Kaga, C. and Kolbinger, B. and Leali, M. and Lehner, S. and Rizzini, E. Lodi and Malbrunot, C. and Mascagna, V. and Massiczek, O. and Murtagh, D. J. and Nagata, Y. and Radics, B. and Simon, M. C. and Suzuki, K. and Tajima, M. and Ulmer, S. and Vamosi, S. and Gorp, S. van and Zmeskal, J. and Breuker, H. and Higaki, H. and Kanai, Y. and Kuroda, N. and Matsuda, Y. and Venturelli, L. and Widmann, E. and Yamazaki, Y.} } @article {75, title = {The ASACUSA CUSP: an antihydrogen experiment}, journal = {Hyperfine Interactions}, volume = {235}, year = {2015}, pages = {13{\textendash}20}, abstract = {In order to test CPT symmetry between antihydrogen and its counterpart hydrogen, the ASACUSA collaboration plans to perform high precision microwave spectroscopy of ground-state hyperfine splitting of antihydrogen atom in-flight. We have developed an apparatus ({\textquoteleft}{\textquoteleft}cusp trap{\textquoteright}{\textquoteright}) which consists of a superconducting anti-Helmholtz coil and multiple ring electrodes. For the preparation of slow antiprotons and positrons, Penning-Malmberg type traps were utilized. The spectrometer line was positioned downstream of the cusp trap. At the end of the beamline, an antihydrogen beam detector was located, which comprises an inorganic Bismuth Germanium Oxide (BGO) single-crystal scintillator housed in a vacuum duct and surrounding plastic scintillators. A significant fraction of antihydrogen atoms flowing out the cusp trap were detected.}, issn = {1572-9540}, doi = {10.1007/s10751-015-1205-1}, url = {http://dx.doi.org/10.1007/s10751-015-1205-1}, author = {Kuroda, N. and Ulmer, S. and Murtagh, D. J. and Gorp, S. and Nagata, Y. and Diermaier, M. and Federmann, S. and Leali, M. and Malbrunot, C. and Mascagna, V. and Massiczek, O. and Michishio, K. and Mizutani, T. and Mohri, A. and Nagahama, H. and Ohtsuka, M. and Radics, B. and Sakurai, S. and Sauerzopf, C. and Suzuki, K. and Tajima, M. and Torii, H. A. and Venturelli, L. and W{\"u}nschek, B. and Zmeskal, J. and Zurlo, N. and Higaki, H. and Kanai, Y. and Rizzini, E. Lodi and Nagashima, Y. and Matsuda, Y. and Widmann, E. and Yamazaki, Y.} } @article {72, title = {An atomic hydrogen beam to test ASACUSA{\textquoteright}s apparatus for antihydrogen spectroscopy}, journal = {Hyperfine Interactions}, volume = {233}, year = {2015}, pages = {35-40}, keywords = {Antihydrogen, Atomic hydrogen, Ground state hyperfine structure}, issn = {0304-3843}, doi = {10.1007/s10751-015-1151-y}, url = {http://dx.doi.org/10.1007/s10751-015-1151-y}, author = {Diermaier, M. and Caradonna, P. and Kolbinger, B. and Malbrunot, C. and Massiczek, O. and Sauerzopf, C. and Simon, M.C. and Wolf, M. and Zmeskal, J. and Widmann, E.} } @article {71, title = {Towards a precise measurement of the antihydrogen ground state hyperfine splitting in a beam: the case of in-flight radiative decays}, journal = {Journal of Physics B: Atomic, Molecular and Optical Physics}, volume = {48}, year = {2015}, month = {29/07/2015}, pages = {184001}, abstract = {

The ASACUSA antihydrogen setup at the CERN Antiproton Decelerator (AD) consists of an antihydrogen source (cusp magnet coupled to a positron source and an antiproton catching magnet) followed by a spectrometer beamline. After production in the cusp, the antihydrogen atoms decay while they escape the trap leading to changes in their effective magnetic moment which in turn affect their trajectories in the beamline. Those sequential decays in the presence of a varying magnetic field strength from their production point in the cusp to their detection at the end of the spectrometer line can in principle greatly affect the prospects for a precision measurement of the antihydrogen hyperfine splitting given the so-far relatively low number of available anti-atoms. The impact of the antihydrogen decay in this context has for the first time been simulated. The implementation of atomic radiative decay has been done in Geant4 to extend the particle tracking capabilities originally embedded in Geant4 to excited atoms, and to allow studies of the effect of dynamic atomic properties on trajectories. This new tool thus allows the study of particle{\textendash}matter interaction via the Geant4 toolkit while properly taking into account the atomic nature of the object under study. The implementation as well as impacts on the experimental sensitivity for antihydrogen spectroscopy are discussed in this paper.

}, keywords = {Antihydrogen, ground state hyperfine splitting measurement, radiative decay}, url = {http://stacks.iop.org/0953-4075/48/i=18/a=184001}, author = {R Lundmark and C Malbrunot and Y Nagata and B Radics and C Sauerzopf and E Widmann} } @article {64, title = {First Observation of a (1,0) Mode Frequency Shift of an Electron Plasma at Antiproton Beam Injection}, journal = {Phys. Rev. Lett.}, volume = {113}, year = {2014}, month = {Jul}, pages = {025001}, abstract = {

The frequency shift of the center-of-mass oscillation, known as the (1,0) mode, of a trapped electron plasma and, furthermore, its time evolution were observed during the cooling of an injected antiproton beam for the first time. Here, antiprotons mixed with the electrons did not follow faster electron oscillations but contributed to the modification of the effective potential. The time evolution of the plasma temperature, deduced from the frequency shift of the excited (3,0) mode, suggested that there was an abnormal energy deposition of the antiproton beam in the electron plasma before thermalization.

}, doi = {10.1103/PhysRevLett.113.025001}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.113.025001}, author = {Kuroda, N. and Mohri, A. and Torii, H.A. and Nagata, Y. and Shibata, M.} } @article {56, title = {A source of antihydrogen for in-flight hyperfine spectroscopy}, journal = {Nat Commun}, volume = {5}, year = {2014}, month = {21/01/2014}, abstract = {

Antihydrogen, a positron bound to an antiproton, is the simplest antiatom. Its counterpart{\textemdash}hydrogen{\textemdash}is one of the most precisely investigated and best understood systems in physics research. High-resolution comparisons of both systems provide sensitive tests of CPT symmetry, which is the most fundamental symmetry in the Standard Model of elementary particle physics. Any measured difference would point to CPT violation and thus to new physics. Here we report the development of an antihydrogen source using a cusp trap for in-flight spectroscopy. A total of 80 antihydrogen atoms are unambiguously detected 2.7 m downstream of the production region, where perturbing residual magnetic fields are small. This is a major step towards precision spectroscopy of the ground-state hyperfine splitting of antihydrogen using Rabi-like beam spectroscopy.

}, url = {http://dx.doi.org/10.1038/ncomms4089}, author = {Kuroda, N. and Ulmer, S. and Murtagh, D. J. and Van Gorp, S. and Nagata, Y. and Diermaier, M. and Federmann, S. and Leali, M. and Malbrunot, C. and Mascagna, V. and Massiczek, O. and Michishio, K. and Mizutani, T. and Mohri, A. and Nagahama, H. and Ohtsuka, M. and Radics, B. and Sakurai, S. and Sauerzopf, C. and Suzuki, K. and Tajima, M. and Torii, H. A. and Venturelli, L. and Wu{\textasciidieresis}nschek, B. and Zmeskal, J. and Zurlo, N. and Higaki, H. and Kanai, Y. and Lodi Rizzini, E. and Nagashima, Y. and Matsuda, Y. and Widmann, E. and Yamazaki, Y.} } @article {67, title = {Spectroscopy apparatus for the measurement of the hyperfine structure of antihydrogen}, journal = {Hyperfine Interactions}, year = {2014}, pages = {1-6}, keywords = {Antihydrogen, CPT symmetry, Hyperfine spectroscopy}, issn = {0304-3843}, doi = {10.1007/s10751-014-1013-z}, url = {http://dx.doi.org/10.1007/s10751-014-1013-z}, author = {Malbrunot, C. and Caradonna, P. and Diermaier, M. and Dilaver, N. and Friedreich, S. and Kolbinger, B. and Lehner, S. and Lundmark, R. and Massiczek, O. and Radics, B. and Sauerzopf, C. and Simon, M. and Widmann, E. and Wolf, M. and W{\"u}nschek, B. and Zmeskal, J.} } @article {66, title = {Towards a spin polarized antihydrogen beam}, journal = {Hyperfine Interactions}, year = {2014}, pages = {1-10}, keywords = {Antihydrogen, Atomic beam, CPT invariance, Rydberg atom}, issn = {0304-3843}, doi = {10.1007/s10751-014-1016-9}, url = {http://dx.doi.org/10.1007/s10751-014-1016-9}, author = {Kuroda, N. and Ulmer, S. and Murtagh, D.J. and Van Gorp, S. and Nagata, Y. and Diermaier, M. and Federmann, S. and Leali, M. and Malbrunot, C. and Mascagna, V. and Massiczek, O. and Michishio, K. and Mizutani, T. and Mohri, A. and Nagahama, H. and Ohtsuka, M. and Radics, B. and Sakurai, S. and Sauerzopf, C. and Suzuki, K. and Tajima, M. and Torii, H.A. and Venturelli, L. and W{\"u}nschek, B. and Zmeskal, J. and Zurlo, N. and Higaki, H. and Kanai, Y. and Lodi-Rizzini, E. and Nagashima, Y. and Matsuda, Y. and Widmann, E. and Yamazaki, Y.} } @article {54, title = {Measurement of the hyperfine structure of antihydrogen in a beam}, journal = {Hyperfine Interactions}, volume = {215}, year = {2013}, pages = {1-8}, keywords = {Antihydrogen, CPT, Precision spectroscopy}, issn = {0304-3843}, doi = {10.1007/s10751-013-0809-6}, url = {http://dx.doi.org/10.1007/s10751-013-0809-6}, author = {Widmann, E. and Diermaier, M. and Juhasz, B. and Malbrunot, C. and Massiczek, O. and Sauerzopf, C. and Suzuki, K. and W{\"u}nschek, B. and Zmeskal, J. and Federmann, S. and Kuroda, N. and Ulmer, S. and Yamazaki, Y.} } @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 {23, title = {Development of a monoenergetic ultraslow antiproton beam source for high-precision investigation}, journal = {Physical Review Special Topics - Accelerators and BeamsPhys. Rev. ST Accel. Beams}, volume = {15}, year = {2012}, month = {2012/02/17/}, pages = {024702 -}, url = {http://link.aps.org/doi/10.1103/PhysRevSTAB.15.024702}, author = {Kuroda, N. and Torii, H. A. and Nagata, Y. and Shibata, M. and Enomoto, Y. and Imao, H. and Kanai, Y. and Hori, M. and Saitoh, H. and Higaki, H. and Mohri, A. and Fujii, K. and Kim, C. H. and Matsuda, Y. and Michishio, K. and Nagashima, Y. and Ohtsuka, M. and Tanaka, K. and Yamazaki, Y.} } @article {29, title = {ASACUSA MUSASHI: New progress with intense ultra slow antiproton beam}, journal = {Hyperfine Interactions}, volume = {194}, year = {2009}, pages = {71-76}, keywords = {Antihydrogen, Antiproton, Positron}, issn = {0304-3843}, doi = {10.1007/s10751-009-0032-7}, url = {http://dx.doi.org/10.1007/s10751-009-0032-7}, author = {Imao, H. and Tarek, M. and Michishio, K. and Enomoto, Y. and Shimoyama, T. and Kanai, Y. and Kuroda, N. and Mohri, A. and Higaki, H. and Saitoh, H. and Torii, H.A. and Nagata, Y. and Toyoda, H. and Matsuda, Y. and Nagashima, Y. and Yamazaki, Y.} } @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 {16, title = {Compact cryogenic system with mechanical cryocoolers for antihydrogen synthesis}, journal = {Review of Scientific InstrumentsRev. Sci. Instrum.}, volume = {79}, year = {2008}, month = {2008/01/00/}, pages = {015112 - 4}, keywords = {cryogenics, exotic atoms, hydrogen, vacuum techniques}, url = {http://dx.doi.org/10.1063/1.2834876}, author = {Shibata, M. and Mohri, A. and Kanai, Y. and Enomoto, Y. and Yamazaki, Y.} } @article {34, title = {Observation of Ultra-Slow Antiprotons using Micro-channel Plate}, journal = {AIP Conference Proceedings}, volume = {1037}, year = {2008}, pages = {311-317}, keywords = {elementary particles, nuclear fragmentation, protons}, doi = {10.1063/1.2977850}, url = {http://link.aip.org/link/?APC/1037/311/1}, author = {H. Imao and H. A. Torii and Y. Nagata and H. Toyoda and T. Shimoyama and Y. Enomoto and H. Higaki and Y. Kanai and A. Mohri and Y. Yamazaki}, editor = {Yasuyuki Kanai and Yasunori Yamazaki} } @article {18, title = {Radial compression of a non-neutral plasma in a cusp trap for antihydrogen synthesis}, journal = {Physical Review APhys. Rev. A}, volume = {77}, year = {2008}, month = {2008/05/27/}, pages = {051403 -}, url = {http://link.aps.org/doi/10.1103/PhysRevA.77.051403}, author = {Saitoh, H. and Mohri, A. and Enomoto, Y. and Kanai, Y. and Yamazaki, Y.} } @article {17, title = {Radial Compression of an Antiproton Cloud for Production of Intense Antiproton Beams}, journal = {Physical Review LettersPhys. Rev. Lett.}, volume = {100}, year = {2008}, month = {2008/05/19/}, pages = {203402 -}, url = {http://link.aps.org/doi/10.1103/PhysRevLett.100.203402}, author = {Kuroda, N. and Torii, H. A. and Shibata, M. and Nagata, Y. and Barna, D. and Hori, M. and Horvath, D. and Mohri, A. and Eades, J. and Komaki, K. and Yamazaki, Y.} } @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.} } @article {27, title = {Antiproton and Electron Plasma Behavior and its Control for Production of Ultraslow Antiproton Beams}, journal = {AIP Conference Proceedings}, volume = {796}, year = {2005}, pages = {321-324}, keywords = {plasma electrostatic waves, proton beams}, doi = {10.1063/1.2130188}, url = {http://link.aip.org/link/?APC/796/321/1}, author = {N. Kuroda and H. A. Torii and M. Shibata and Y. Nagata and D. Barna and M. Hori and A. Mohri and K. Komaki and Y. Yamazaki}, editor = {Dieter Grzonka and Rafa{\l} Czy{\.z}ykiewicz and Walter Oelert and Tomasz Ro{\.z}ek and Peter Winter} } @article {32, title = {ASACUSA Gas-Jet Target: Present Status And Future Development}, journal = {AIP Conference Proceedings}, volume = {793}, year = {2005}, pages = {328-340}, keywords = {atomic beams, computer aided analysis, hadronic atoms, helium, jets, supersonic flow}, doi = {10.1063/1.2121994}, url = {http://link.aip.org/link/?APC/793/328/1}, author = {V. L. Varentsov and N. Kuroda and Y. Nagata and H. A. Torii and M. Shibata and Y. Yamazaki}, editor = {Yasunori Yamazaki and Michiharu Wada} } @article {26, title = {Control of plasmas for production of ultraslow antiproton beams}, journal = {AIP Conference Proceedings}, volume = {793}, year = {2005}, pages = {307-317}, keywords = {atomic beams, hadronic atoms, particle traps, plasma}, doi = {10.1063/1.2121992}, url = {http://link.aip.org/link/?APC/793/307/1}, author = {N. Kuroda and H. A. Torii and M. Shibata and Y. Nagata and D. Barna and D. Horv{\'a}th and M. Hori and J. Eades and A. Mohri and K. Komaki and Y. Yamazaki}, editor = {Yasunori Yamazaki and Michiharu Wada} } @article {25, title = {Production of ultra-slow antiproton beams}, journal = {AIP Conference Proceedings}, volume = {793}, year = {2005}, pages = {293-306}, keywords = {atomic beams, hadronic atoms, plasma}, doi = {10.1063/1.2121991}, url = {http://link.aip.org/link/?APC/793/293/1}, author = {Torii, Hiroyuki A. and N. Kuroda and M. Shibata and Y. Nagata and D. Barna and M. Hori and J. Eades and A. Mohri and K. Komaki and Y. Yamazaki}, editor = {Yasunori Yamazaki and Michiharu Wada} } @article {33, title = {Multi-ring trap as a reservoir of cooled antiprotons}, journal = {AIP Conference Proceedings}, volume = {498}, year = {1999}, pages = {59-64}, keywords = {antimatter, cooling, electric fields, electrodes, magnetic fields, particle traps, storage rings}, doi = {10.1063/1.1302101}, url = {http://link.aip.org/link/?APC/498/59/1}, author = {T. Ichioka and H. Higaki and M. Hori and N. Oshima and K. Kuroki and A. Mohri and K. Komaki and Y. Yamazaki}, editor = {John J. Bollinger and Ronald C. Davidson and Ross L. Spencer} }