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The HYDRA pion-tracker for hypernuclei studies at R3B
Authors:
Lian-Cheng Ji,
Uwe Bonnes,
Mikolaj Cwiok,
Meytal Duer,
Alexandru Enciu,
Piotr Gasik,
Joerg Hehner,
Alexandre Obertelli,
Shinsuke Ota,
Valerii Panin,
Jerome Pibernat,
Dominic Rossi,
Haik Simon,
Yelei Sun,
Simone Velardita,
Frank Wienholtz,
Marcin Zaremba
Abstract:
The HYpernuclei-Decay at R3B Apparatus (HYDRA) tracker is a novel time projection chamber combined with a plastic scintillator wall for timing and trigger purposes. This detector is a low radiation length tracker dedicated to measuring pions from the weak decay of light hypernuclei produced from ion-ion collisions at few GeV/nucleon in the magnetic field of the large-acceptance dipole magnet GLAD…
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The HYpernuclei-Decay at R3B Apparatus (HYDRA) tracker is a novel time projection chamber combined with a plastic scintillator wall for timing and trigger purposes. This detector is a low radiation length tracker dedicated to measuring pions from the weak decay of light hypernuclei produced from ion-ion collisions at few GeV/nucleon in the magnetic field of the large-acceptance dipole magnet GLAD at the Reactions with Relativistic Radioactive Beams (R3B) experiment at GSI-FAIR. In this paper, we describe the design of the detector and provide the results of its first characterizations.
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Submitted 14 April, 2025;
originally announced April 2025.
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Development of fast-response PPAC with strip-readout for heavy-ion beams
Authors:
Shutaro Hanai,
Shinsuke Ota,
Reiko Kojima,
Shoichiro Masuoka,
Masanori Dozono,
Nobuaki Imai,
Shin'ichiro Michimasa,
Susumu Shimoura,
Juzo Zenihiro,
Kento Inaba,
Yuto Hijikata,
Ru Longhi,
Ryo Nakajima
Abstract:
A strip-readout parallel-plate avalanche counter (SR-PPAC) has been developed aiming at the high detection efficiency and good position resolution in high-intensity heavy-ion measurements. The performance was evaluated using 115 MeV/u $^{132}$Xe, 300 MeV/u $^{132}$Sn, and 300 MeV/u $^{48}$Ca beams. A detection efficiency beyond 99% for these beams is achieved even at an incident beam intensity of…
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A strip-readout parallel-plate avalanche counter (SR-PPAC) has been developed aiming at the high detection efficiency and good position resolution in high-intensity heavy-ion measurements. The performance was evaluated using 115 MeV/u $^{132}$Xe, 300 MeV/u $^{132}$Sn, and 300 MeV/u $^{48}$Ca beams. A detection efficiency beyond 99% for these beams is achieved even at an incident beam intensity of 0.7 billion particles per second. The best position resolution achieved is 235 um (FWHM).
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Submitted 24 August, 2023;
originally announced August 2023.
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BlueSTEAl: A pair of silicon arrays and a zero-degree phoswich detector for studies of scattering and reactions in inverse kinematics
Authors:
Shuya Ota,
Greg Christian,
Ben J. Reed,
Wilton N. Catford,
Stefania Dede,
Daniel T. Doherty,
Gavin Lotay,
Michael Roosa,
Antti Saastamoinen,
Dustin P. Scriven
Abstract:
BlueSTEAl, the Blue (aluminum chamber of) Silicon TElescope Arrays for light nuclei,has been developed to study direct reactions in inverse kinematics, as well as scattering and breakup reactions using radioactive ion beams. It is a detector system consisting of a pair of annular silicon detector arrays and a zero-degree phoswich plastic scintillator. For typical binary reaction studies in inverse…
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BlueSTEAl, the Blue (aluminum chamber of) Silicon TElescope Arrays for light nuclei,has been developed to study direct reactions in inverse kinematics, as well as scattering and breakup reactions using radioactive ion beams. It is a detector system consisting of a pair of annular silicon detector arrays and a zero-degree phoswich plastic scintillator. For typical binary reaction studies in inverse kinematics, light ions are detected by the Si array in coincidence with heavy recoils detected by the phoswich placed at the focal-plane of a zero-degree magnetic spectrometer. The Si array can also be used to detect light nuclei such as berylium and carbon with clear isotope separation, while the phoswich can also be placed at zero degrees without a spectrometer and used as a high-efficiency beam counting monitor with particle identification capability at the rate of up to 5*10^4 particles per second. This paper reports on the capabilities of BlueSTEAl as determined by recent experiments performed at the Texas A&M Cyclotron Institute. The device is also anticipated to be used in future experiments at other radioactive ion beam facilities.
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Submitted 27 July, 2023;
originally announced July 2023.
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Silicon tracker array for RIB experiments at SAMURAI
Authors:
A. I. Stefanescu,
V. Panin,
L. Trache,
T. Motobayashi,
H. Otsu,
A. Saastamoinen,
T. Uesaka,
L. Stuhl,
J. Tanaka,
D. Tudor,
I. C. Stefanescu,
A. E. Spiridon,
K. Yoneda,
H. Baba,
M. Kurokawa,
Y. Togano,
Z. Halasz,
M. Sasano,
S. Ota,
Y. Kubota,
D. S. Ahn,
T. Kobayashi,
Z. Elekes,
N. Fukuda,
H. Takeda
, et al. (27 additional authors not shown)
Abstract:
This work describes a silicon tracker system developed for experiments with proton-rich radioactive ion beams at the SAMURAI superconducting spectrometer of RIBF at RIKEN. The system is designed for accurate angular reconstruction and atomic number identification of relativistic heavy ions and protons which are simultaneously produced in reactions motivated by studies of proton capture reactions o…
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This work describes a silicon tracker system developed for experiments with proton-rich radioactive ion beams at the SAMURAI superconducting spectrometer of RIBF at RIKEN. The system is designed for accurate angular reconstruction and atomic number identification of relativistic heavy ions and protons which are simultaneously produced in reactions motivated by studies of proton capture reactions of interest for nuclear astrophysics. The technical characteristics of the tracking array are described in detail as are its performance in two pilot experiments. The physics justification for such a system is also presented.
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Submitted 13 July, 2023;
originally announced July 2023.
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Experimental Verification of a One-Dimensional Diffraction-Limit Coronagraph
Authors:
Satoshi Itoh,
Taro Matsuo,
Shunsuke Ota,
Kensuke Hara,
Yuji Ikeda,
Reiki Kojima,
Toru Yamada,
Takahiro Sumi
Abstract:
We performed an experimental verification of a coronagraph. As a result, we confirmed that, at the focal region where the planetary point spread function exists, the coronagraph system mitigates the raw contrast of a star-planet system by at least $1\times10^{-5}$ even for the 1-$λ/D$ star-planet separation. In addition, the verified coronagraph keeps the shapes of the off-axis point spread functi…
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We performed an experimental verification of a coronagraph. As a result, we confirmed that, at the focal region where the planetary point spread function exists, the coronagraph system mitigates the raw contrast of a star-planet system by at least $1\times10^{-5}$ even for the 1-$λ/D$ star-planet separation. In addition, the verified coronagraph keeps the shapes of the off-axis point spread functions when the setup has the source angular separation of 1$λ/D$. The low-order wavefront error and the non-zero extinction ratio of the linear polarizer may affect the currently confirmed contrast. The sharpness of the off-axis point spread function generated by the sub-$λ/D$ separated sources is promising for the fiber-based observation of exoplanets. The coupling efficiency with a single mode fiber exceeds 50% when the angular separation is greater than 3--4$\times 10^{-1}λ/D$. For sub-$λ/D$ separated sources, the peak positions (obtained with Gaussian fitting) of the output point spread functions are different from the angular positions of sources; the peak position moved from about $0.8λ/D$ to $1.0λ/D$ as the angular separation of the light source varies from $0.1λ/D$ to $1.0λ/D$. The off-axis throughput including the fiber-coupling efficiency (with respect to no focal plane mask) is about 40% for 1-$λ/D$ separated sources and 10% for 0.5-$λ/D$ separated ones (excluding the factor of the ratio of pupil aperture width and Lyot stop width), where we assumed a linear-polarized-light injection. In addition, because this coronagraph can remove point sources on a line in the sky, it has another promising application for high-contrast imaging of exoplanets in binary systems.
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Submitted 1 June, 2023;
originally announced June 2023.
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Performance of prototype Dual Gain Multilayer Thick GEM with high-intensity heavy-ion beam injections in low-pressure hydrogen gas
Authors:
Chihiro Iwamoto,
Shinsuke Ota,
Reiko Kojima,
Hiroshi Tokieda,
Seiya Hayakawa,
Yutaka Mizoi,
Taku Gunji,
Hidetoshi Yamaguchi,
Nobuaki Imai,
Masanori Dozono,
Ryo Nakajima,
Olga Beliuskina,
Shin'ichiro Michimasa,
Rin Yokoyama,
Keita Kawata,
Daisuke Suzuki,
Tadaaki Isobe,
Juzo Zenihiro,
Yohei Matsuda,
Jun Okamoto,
Tetsuya Murakami,
Eiichi Takada
Abstract:
A prototype Dual Gain Multilayer Thick Gas Electron Multilyer (DG-M-THGEM) with an active area of 10 cm $\times$ 10 cm was manufactured aiming at the production of a large-volume active-target time projection chamber which can work under the condition of high-intensity heavy-ion beam injections. The DG-M-THGEM has a alternating structure of electrodes and insulators. Effective gas gains of two reg…
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A prototype Dual Gain Multilayer Thick Gas Electron Multilyer (DG-M-THGEM) with an active area of 10 cm $\times$ 10 cm was manufactured aiming at the production of a large-volume active-target time projection chamber which can work under the condition of high-intensity heavy-ion beam injections. The DG-M-THGEM has a alternating structure of electrodes and insulators. Effective gas gains of two regions, which are called beam and recoil regions, are separately controlled. Performance of the prototype DG-M-THGEM in hydrogen gas at a pressure of 40 kPa was evaluated. Irradiating a $^{132}$Xe beam, an effective gas gain lower than 100 with a charge resolution of 3% was achieved in the beam region while the effective gas gain of 2000 was maintained in the recoil region. Position distributions of measured charges along the beam axis were investigated in order to evaluate gain uniformity in the high intensity beam injection. The gain shift was estimated by simulations considering space charges in the drift region. The gain shift was suppressed within 3% even at the beam intensity of 2.5 $\times$ 10$^{6}$ particles per second.
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Submitted 12 May, 2023;
originally announced May 2023.
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A Position and Pulse Shape Discriminant p-Terphenyl Detector Module
Authors:
D. P. Scriven,
G. Christian,
G. V. Rogachev,
C. E. Parker,
L. G. Sobotka,
S. Ahn,
G. Chubarian,
S. Ota,
E. Aboud,
J. Bishop,
E. Koshchiy,
A. G. Thomas
Abstract:
We present the development of a neutron detector array module made with $\textit{para}$-terphenyl, a bright, fast, n/$γ$ discriminating crystalline organic scintillator. The module is comprised of 2 cm $\times$ 2 cm $\times$ 2 cm $\textit{p}$-terphenyl crystals that have been optically coupled together to create a $\textit{pseudo-bar}$ module. While only relying on two photo detectors, the module…
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We present the development of a neutron detector array module made with $\textit{para}$-terphenyl, a bright, fast, n/$γ$ discriminating crystalline organic scintillator. The module is comprised of 2 cm $\times$ 2 cm $\times$ 2 cm $\textit{p}$-terphenyl crystals that have been optically coupled together to create a $\textit{pseudo-bar}$ module. While only relying on two photo detectors, the module is capable of distinguishing interactions between up to eight crystals. Furthermore, the module retains the $\textit{p}$-terphenyl's pulse shape discrimination (PSD) capability. Together this makes the pseudo-bar module a promising position-sensitive neutron detector. Here we present characteristics of the pseudo-bar module - its timing resolution as well as its pulse shape and position discrimination capabilities, and briefly discuss future plans for utilizing an array of pseudo-bar modules in a useful neutron detector system.
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Submitted 29 June, 2021;
originally announced June 2021.
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Development and operation of an electrostatic time-of-flight detector for the Rare RI storage Ring
Authors:
D. Nagae,
Y. Abe,
S. Okada,
S. Omika,
K. Wakayama,
S. Hosoi,
S. Suzuki,
T. Moriguchi,
M. Amano,
D. Kamioka,
Z. Ge,
S. Naimi,
F. Suzaki,
N. Tadano,
R. Igosawa,
K. Inomata,
H. Arakawa,
K. Nishimuro,
T. Fujii,
T. Mitsui,
Y. Yanagisawa,
H. Baba,
S. Michimasa,
S. Ota,
G. Lorusso
, et al. (6 additional authors not shown)
Abstract:
An electrostatic time-of-flight detector named E-MCP has been developed for quick diagnostics of circulating beam and timing measurement in mass spectrometry at the Rare-RI Ring in RIKEN. The E-MCP detector consists of a conversion foil, potential grids, and a microchannel plate. Secondary electrons are released from the surface of the foil when a heavy ion hits it. The electrons are accelerated a…
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An electrostatic time-of-flight detector named E-MCP has been developed for quick diagnostics of circulating beam and timing measurement in mass spectrometry at the Rare-RI Ring in RIKEN. The E-MCP detector consists of a conversion foil, potential grids, and a microchannel plate. Secondary electrons are released from the surface of the foil when a heavy ion hits it. The electrons are accelerated and deflected by 90$^\circ$ toward the microchannel plate by electrostatic potentials. A thin carbon foil and a thin aluminum-coated mylar foil were used as conversion foils. We obtained time resolutions of 69(1) ps and 43(1) ps (standard deviation) for a $^{84}$Kr beam at an energy of 170 MeV/u when using the carbon and the aluminum-coated mylar foils, respectively. A detection efficiency of approximately 90% was obtained for both foils. The E-MCP detector equipped with the carbon foil was installed inside the Rare-RI Ring to confirm particle circulation within a demonstration experiment on mass measurements of nuclei around $^{78}$Ge produced by in-flight fission of uranium beam at the RI Beam Factory in RIKEN. Periodic time signals from circulating ions were clearly observed. Revolution times for $^{78}$Ge, $^{77}$Ga, and $^{76}$Zn were obtained. The results confirmed successful circulation of the short-lived nuclei inside the Rare-RI Ring.
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Submitted 3 November, 2020;
originally announced November 2020.
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Construction of KAGRA: an Underground Gravitational Wave Observatory
Authors:
T. Akutsu,
M. Ando,
S. Araki,
A. Araya,
T. Arima,
N. Aritomi,
H. Asada,
Y. Aso,
S. Atsuta,
K. Awai,
L. Baiotti,
M. A. Barton,
D. Chen,
K. Cho,
K. Craig,
R. DeSalvo,
K. Doi,
K. Eda,
Y. Enomoto,
R. Flaminio,
S. Fujibayashi,
Y. Fujii,
M. -K. Fujimoto,
M. Fukushima,
T. Furuhata
, et al. (202 additional authors not shown)
Abstract:
Major construction and initial-phase operation of a second-generation gravitational-wave detector KAGRA has been completed. The entire 3-km detector is installed underground in a mine in order to be isolated from background seismic vibrations on the surface. This allows us to achieve a good sensitivity at low frequencies and high stability of the detector. Bare-bones equipment for the interferomet…
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Major construction and initial-phase operation of a second-generation gravitational-wave detector KAGRA has been completed. The entire 3-km detector is installed underground in a mine in order to be isolated from background seismic vibrations on the surface. This allows us to achieve a good sensitivity at low frequencies and high stability of the detector. Bare-bones equipment for the interferometer operation has been installed and the first test run was accomplished in March and April of 2016 with a rather simple configuration. The initial configuration of KAGRA is named {\it iKAGRA}. In this paper, we summarize the construction of KAGRA, including the study of the advantages and challenges of building an underground detector and the operation of the iKAGRA interferometer together with the geophysics interferometer that has been constructed in the same tunnel.
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Submitted 11 December, 2017; v1 submitted 30 November, 2017;
originally announced December 2017.
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Separated flow operation of the SHARAQ spectrometer for in-flight proton decay experiments
Authors:
M. Dozono,
T. Uesaka,
S. Michimasa,
M. Takaki,
M. Kobayashi,
M. Matsushita,
S. Ota,
H. Tokieda,
S. Shimoura
Abstract:
New operation mode, "separated flow mode", has been developed for in-flight proton decay experiments with the SHARAQ spectrometer. In the separated flow mode, the protons and the heavy-ion products are separated and measured in coincidence at two different focal planes of SHARAQ. The ion-optical properties of the new mode were studied by using a proton beam at $246~{\rm MeV}$, and the momentum vec…
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New operation mode, "separated flow mode", has been developed for in-flight proton decay experiments with the SHARAQ spectrometer. In the separated flow mode, the protons and the heavy-ion products are separated and measured in coincidence at two different focal planes of SHARAQ. The ion-optical properties of the new mode were studied by using a proton beam at $246~{\rm MeV}$, and the momentum vector was properly reconstructed from the parameters measured in the focal plane of SHARAQ. In the experiment with the $({}^{16}{\rm O},{}^{16}{\rm F})$ reaction at a beam energy of $247~{\rm MeV/u}$, the outgoing ${}^{15}{\rm O}+p$ produced by the decay of ${}^{16}{\rm F}$ were measured in coincidence with SHARAQ. High energy resolutions of $100~{\rm keV}$ (FWHM) and $\sim 2~{\rm MeV}$ were achieved for the relative energy of $535~{\rm keV}$, and the ${}^{16}{\rm F}$ energy of $3940~{\rm MeV}$, respectively.
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Submitted 29 January, 2016;
originally announced February 2016.
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Plasmonic Brownian ratchet
Authors:
Paloma A. Huidobro,
Sadao Ota,
Xiaodong Yang,
Xiaobo Yin,
F. J. Garcia-Vidal,
Xiang Zhang
Abstract:
Here we present a Brownian ratchet based on plasmonic interactions. By periodically turning on and off a laser beam that illuminates a periodic array of plasmonic nanostructures with broken spatial symmetry, the random thermal motion of a subwavelength dielectric bead is rectified into one direction. By means of the Molecular Dynamics technique we show a statistical directed drift in particle flow…
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Here we present a Brownian ratchet based on plasmonic interactions. By periodically turning on and off a laser beam that illuminates a periodic array of plasmonic nanostructures with broken spatial symmetry, the random thermal motion of a subwavelength dielectric bead is rectified into one direction. By means of the Molecular Dynamics technique we show a statistical directed drift in particle flow.
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Submitted 23 January, 2014;
originally announced January 2014.