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1. Effect of Gold Nanoparticle Radiosensitization on Plasmid DNA Damage Induced by High-Dose-Rate Brachytherapy

Author

Yogo K, Misawa M, Shimizu M, Shimizu H, Kitagawa T, Hirayama R, Ishiyama H, Furukawa T, and Yasuda H

Subjects
gold nanoparticles, high-dose-rate brachytherapy, dna damage, radiosensitization, 192ir γ-rays, positively charged nanoparticles, Medicine (General), R5-920
Abstract

Katsunori Yogo,1 Masaki Misawa,2 Morihito Shimizu,2 Hidetoshi Shimizu,3 Tomoki Kitagawa,3 Ryoichi Hirayama,4 Hiromichi Ishiyama,5 Takako Furukawa,1 Hiroshi Yasuda6 1Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; 2Health and Medical Research Institute, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, Japan; 3Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan; 4National Institute of Radiological Sciences (NIRS), National Institutes for Quantum and Radiological Science and Technology (QST), Chiba-shi, Chiba, Japan; 5Graduate School of Medical Science, Kitasato University, Sagamihara, Kanagawa, Japan; 6Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, JapanCorrespondence: Katsunori YogoNagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-Ku, Nagoya, Aichi 461-8673, JapanTel +81 52 719 1103Fax +81 52 719 3172Email yogo@met.nagoya-u.ac.jpPurpose: Gold nanoparticles (AuNPs) are candidate radiosensitizers for medium-energy photon treatment, such as γ-ray radiation in high-dose-rate (HDR) brachytherapy. However, high AuNP concentrations are required for sufficient dose enhancement for clinical applications. Here, we investigated the effect of positively (+) charged AuNP radiosensitization of plasmid DNA damage induced by 192Ir γ-rays, and compared it with that of negatively (−) charged AuNPs.Methods: We observed DNA breaks and reactive oxygen species (ROS) generation in the presence of AuNPs at low concentrations. pBR322 plasmid DNA exposed to 64 ng/mL AuNPs was irradiated with 192Ir γ-rays via HDR brachytherapy. DNA breaks were detected by observing the changes in the form of the plasmid and quantified by agarose gel electrophoresis. The ROS generated by the AuNPs were measured with the fluorescent probe sensitive to ROS. The effects of positively (+) and negatively (−) charged AuNPs were compared to study the effect of surface charge on dose enhancement.Results: +AuNPs at lower concentrations promoted a comparable level of radiosensitization by producing both single-stranded breaks (SSBs) and double-stranded breaks (DSBs) than those used in cell assays and Monte Carlo simulation experiments. The dose enhancement factor (DEF) for +AuNPs was 1.3 ± 0.2 for SSBs and 1.5 ± 0.4 for DSBs. The ability of +AuNPs to augment plasmid DNA damage is due to enhanced ROS generation. While −AuNPs generated similar ROS levels, they did not cause significant DNA damage. Thus, dose enhancement using low concentrations of +AuNPs presumably occurred via DNA binding or increasing local +AuNP concentration around the DNA.Conclusion: +AuNPs at low concentrations displayed stronger radiosensitization compared to −AuNPs. Combining +AuNPs with 192Ir γ-rays in HDR brachytherapy is a candidate method for improving clinical outcomes. Future development of cancer cell-specific +AuNPs would allow their wider application for HDR brachytherapy.Keywords: gold nanoparticles, high-dose-rate brachytherapy, DNA damage, radiosensitization, 192Ir γ-rays, positively charged nanoparticles

Published
2021

2. 7Be and 8B reaction dynamics at Coulomb barrier energies

Author

Strano E., Mazzocco M., Boiano A., Boiano C., La Commara M., Manea C., Parascandolo C., Pierroutsakou D., Signorini C., Torresi D., Yamaguchi H., Kahl D., Acosta L., Di Meo P., Fernandez-Garcia J.P., Glodariu T., Grebosz J., Guglielmetti A., Imai N., Hirayama Y., Ishiyama H., Iwasa N., Jeong S.C., Jia H.M., Keeley N., Kim Y.H., Kimura S., Kubono S., Lay J.A., Lin C.J., Marquinez-Duran G., Marte I., Miyatake H., Mukai M., Nakao T., Nicoletto M., Pakou A., Rusek K., Sakaguchi Y., Sanchez-Benitez A.M., Sava T., Sgouros O., Stefanini C., Soramel F., Soukeras V., Stiliaris E., Stroe L., Teranishi T., Toniolo N., Wakabayashi Y., Watanabe Y.X., Yang L., and Yang Y.Y.

Subjects
Physics, QC1-999
Abstract

We investigated the reaction dynamics induced by the 7Be,8B+208Pb collisions at energies around the Coulomb barrier. Charged particles originated by both the col- lisions were detected by means of 6 ΔE-Eres telescopes of a newly developed detector array. Experimental data were analysed within the framework of the Optical Model and the total reaction cross-sections were compared together and with the 6,7Li+208Pb colli-sion data. According to the preliminary results, 7Be nucleus reactivity is rather similar to the 7Li one whereas the 8B+208Pb total reaction cross section appears to be much larger than those measured for reactions induced by the other weakly-bound projectiles on the same target.

Published
2018
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3. A new study of the $N=32$ and $N=34$ shell gap for Ti and V by the first high-precision MRTOF mass measurements at BigRIPS-SLOWRI

Author

Iimura, S., Rosenbusch, M., Takamine, A., Tsunoda, Y., Wada, M., Chen, S., Hou, D. S., Xian, W., Ishiyama, H., Yan, S., Schury, P., Crawford, H., Doornenbal, P., Hirayama, Y., Ito, Y., Kimura, S., Koiwai, T., Kojima, T. M., Koura, H., Lee, J., Liu, J., Michimasa, S., Miyatake, H., Moon, J. Y., Nishimura, S., Naimi, S., Niwase, T., Odahara, A., Otsuka, T., Paschalis, S., Petri, M., Shimizu, N., Sonoda, T., Suzuki, D., Watanabe, Y. X., Wimmer, K., and Wollnik, H.

Subjects
Nuclear Experiment
Abstract

The atomic masses of $^{55}$Sc, $^{56,58}$Ti, and $^{56-59}$V have been determined using the high-precision multi-reflection time-of-flight technique. The radioisotopes have been produced at RIKEN's RIBF facility and delivered to the novel designed gas cell and multi-reflection system (ZD MRTOF), which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For $^{56,58}$Ti and $^{56-59}$V the mass uncertainties have been reduced down to the order of $10\,\mathrm{keV}$, shedding new light on the $N=34$ shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species $^{58}$Ti and $^{59}$V. With the new precision achieved, we reveal the non-existence of the $N=34$ empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied $\nu p_{3/2}$ orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the $\nu d_{5/2}$ and $\nu g_{9/2}$ orbits and compare the results with conventional shell model calculations, which exclude the $\nu g_{9/2}$ and the $\nu d_{5/2}$ orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at $N=34$.

Published
2022
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4. 8B + 208Pb Elastic Scattering at Coulomb Barrier Energies

Author

Commara M. La, Mazzocco M., Boiano A., Boiano C., Manea C., Parascandolo C., Pierroutsakou D., Signorini C., Strano E., Torresi D., Yamaguchi H., Kahl D., Meo P. Di, Grebosz J., Imai N., Hirayama Y., Ishiyama H., Iwasa N., Jeong S.C., Jia H.M., Kim Y.H., Kimura S., Kubono S., Lin C.J., Miyatake H., Mukai M., Nakao T., Nicoletto M., Sakaguchi Y., Sánchez-Benítez A.M., Soramel F., Teranishi T., Wakabayashi Y., Watanabe Y.X., Yang L., and Yang Y.Y.

Subjects
Physics, QC1-999
Abstract

The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (S p = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.

Published
2017
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6. 7Be- and 8B-reaction dynamics at Coulomb barrier energies

Author

Mazzocco M., Boiano A., Boiano C., La Commara M., Manea C., Parascandolo C., Pierroutsakou D., Signorini C., Strano E., Torresi D., Yamaguchi H., Kahl D., Acosta L., Di Meo P., Fernandez-Garcia J.P., Glodariu T., Grebosz J., Guglielmetti A., Imai N., Hirayama Y., Ishiyama H., Iwasa N., Jeong S.C., Jia H.M., Keeley N., Kim Y.H., Kimura S., Kubono S., Lay J.A., Lin C.J., Marquinez-Duran G., Martel I., Miyatake H., Mukai M., Nakao T., Nicoletto M., Pakou A., Rusek K., Sakaguchi Y., Sánchez-Benítez A.M., Sava T., Sgouros O., Stefanini C., Soramel F., Soukeras V., Stiliaris E., Stroe L., Teranishi T., Toniolo N., Wakabayashi Y., Watanabe Y.X., Yang L., and Yang Y.Y.

Subjects
Physics, QC1-999
Abstract

We investigated the reaction dynamics induced by the Radioactive Ion Beams 7Be and 8B on a 208Pb target at energies around the Coulomb barrier. The two measurements are strongly interconnected, being 7Be (Sα = 1.586 MeV) the loosely bound core of the even more exotic 8B (Sp = 0.1375 MeV) nucleus. Here we summarize the present status of the data analysis for the measurement of the elastic scattering process for both reactions and the preliminary results for the optical model analysis of the collected data.

Published
2016
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7. Two measurements of the 22Na+p resonant scattering via thick-target inverse-kinematics method

Author

Wang Y.B., Jin S.J., Jing L., Han Z.Y., Bai X.X., Guo B., Li Y.J., Li Z.H., Lian G., Su J., Sun L.J., Yan S.Q., Zeng S., Liu W.P., Yamaguchi H., Kubono S., Hu J., Kahl D., He J.J, Wang J.S., Tang X.D., Xu S.W., Ma P., Zhang N.T., Bai Z., Huang M.R., Jia B.L., Jin S.L., Ma J.B., Ma S.B., Ma W.H., Yang Y.Y., Zhang L.Y., Jung H.S., Moon J.Y., Lee C.S., Teranishi T., Wang H.W., Ishiyama H., Iwasa N., Komatsubara T., and Brown B.A.

Subjects
Physics, QC1-999
Abstract

22Na is an important isotope for the study of extinct radioactivity, meanwhile its sufficiently long half life provides the possibility to observe live 22Na in nearby nova explosions. The 22Na(p,γ) 23Mg is one of the key reactions that influence the 22Na abundance in nova ejecta. To study the proton resonant states in 23Mg relevant to the astrophysical 22Na(p,γ) 23Mg reaction rates, two measurements have been carried out at the CRIB separator of University of Tokyo, and the RIBLL secondary beamline in Lanzhou, respectively. The 22Na secondary beam was produced via the 1H(22Ne, 22Na)n charge exchange reaction. Thick-target inverse-kinematics method is applied to obtain the excitation function of 22Na+p elastic scattering. Extended gas target and solid state polyethylene foil were used in the two measurements, respectively, to map the different excitation energy region of the compound nucleus 23Mg. Several new resonant levels are observed and their contribution to the 22Na(p,γ) 23Mg reaction rate is evaluated.

Published
2016
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8. Beta-decay spectroscopy of r-process nuclei around N = 126

Author

Hirayama Y., Miyatake H., Watanabe Y.X., Imai N., Ishiyama H., Jeong S.C., Jung H.S., Oyaizu M., Mukai M., Kimura S., Sonoda T., Wada M., Kim Y.H., Huyse M., Kudryavtsev Yu., and Van Duppen P.

Subjects
Physics, QC1-999
Abstract

KEK Isotope Separation System (KISS) has been developed at RIKEN to study the β-decay properties of neutron-rich isotopes with neutron numbers around N = 126 to understand the astrophysical site of r-process. These nuclei will be produced by multi-nucleon transfer reactions in neutron-rich heavy ion collisions between 136Xe beam and 198Pt target. The KISS consists of an argon gas cell combined with a laser resonance ionization technique for atomic number selection, of an ISOL mass-separation system and of a detector system for the β-decay spectroscopy of nuclei around N = 126. The argon gas cell of KISS is a key component for thermalizing (stopping and neutralizing) and accumulating the unstable nuclei, and selectively ionizing them by using laser. We have performed off-and on-line experiments to study the basic properties of the gas cell as well as KISS. We successfully extracted the laser-ionized stable 198Pt atoms from the KISS at the commissioning on-line experiments. We furthermore extracted laser-ionized unstable 199Pt atoms and confirmed that the measured half-life was in good agreement with the reported value. Now KISS is ready for lifetime measurements of Pt, Ir, and Os isotopes around N = 126.

Published
2016
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9. The new MRTOF mass spectrograph following the ZeroDegree spectrometer at RIKEN's RIBF facility

Author

Rosenbusch, M., Wada, M., Chen, S., Takamine, A., Iimura, S., Hou, D., Xian, W., Yan, S., Schury, P., Hirayama, Y., Ito, Y., Ishiyama, H., Kimura, S., Kojima, T., Lee, J., Liu, J., Michimasa, S., Miyatake, H., Mukai, M., Moon, J. Y., Nishimura, S., Naimi, S., Niwase, T., Sonoda, T., Watanabe, Y. X., and Wollnik, H.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

A newly assembled multi-reflection time-of-flight mass spectrograph (MRTOF-MS) at RIKEN's RIBF facility became operational for the first time in spring 2020; further modifications and performance tests using stable ions were completed in early 2021. By using a pulsed-drift-tube technique to modify the ions' kinetic energy in a wide range, we directly characterize the dispersion function of the system for use in a new procedure for optimizing the voltages applied to the electrostatic mirrors. Thus far, a mass resolving power of $R_m > 1\,000\,000$ is reached within a total time-of-flight of only $12.5\,\mathrm{ms}$, making the spectrometer capable of studying short-lived nuclei possessing low-lying isomers. Detailed information about the setup and measurement procedure is reported, and an alternative in-MRTOF ion selection scheme to remove molecular contaminants in the absence of a dedicated deflection device is introduced. The setup underwent an initial on-line commissioning at the BigRIPS facility at the end of 2020, where more than 70 nuclear masses have been measured. A summary of the commissioning experiments and results from a test of mass accuracy will be presented., Comment: 13 pages, 11 figures

Published
2021

10. Alpha-decay-correlated mass measurement of 206,207Ra using an $\alpha$-TOF detector equipped MRTOF-MS system

Author

Niwase, T., Wada, M., Schury, P, Brionnet, P., Chen, S. D., Hashimoto, T., Haba, H., Hirayama, Y., Hou, D. S., Iimura, S., Ishiyama, H., Ishizawa, S., Ito, Y., Kaji, D., Kimura, S., Liu, J., Miyatake, H., Moon, J. Y., Morimoto, K., Morita, K., Nagae, D., Rosenbusch, M., Takamine, A., Tanaka, T., Watanabe, Y. X., Wollnik, H., Xian, W., and Ya, S. X.

Subjects
Nuclear Experiment
Abstract

The atomic masses of the isotopes $^{206,207}$Ra have been measured via decay-correlated mass spectroscopy using a multi-reflection time-of-flight mass spectrograph equipped with an $\alpha$-TOF detector. The Ra isotopes were produced as fusion-evaporation products in the $^{51}$V+$^{159}$Tb reaction system and delivered by the gas-filled recoil ion separator GARIS-II at RIKEN. The $\alpha$-TOF detector provides for high-accuracy mass measurements by correlating time-of-flight signals with subsequent $\alpha$-decay events. The masses of $^{206}$Ra and $^{207g,m}$Ra were directly measured using a multi-reflection time-of-flight mass spectrograph equipped with an $\alpha$-TOF detector. A mass excess of ME = 3538(15) keV/c$^2$ and an excitation energy of E$_{\rm ex}$ = 552(42) keV were determined. The $\alpha$-decay branching ratio of $^{207m}$Ra, b$\alpha$ = 0.26(20), was directly determined from decay-correlated time-of-flight signals, and the reduced alpha width of $^{207m}$Ra was calculated to be $\delta^2$ = 50+62-41 keV from the branching ratio. The spin-parity of $^{207m}$Ra was confirmed to be $J^\pi$ = 13/2$^-$ from decay correlated mass measurement results.

Published
2021

11. Study of the multi-nucleon transfer reactions of 136Xe + 198Pt for producing exotic heavy nuclei

Author

Kim Y. H., Watanabe Y. X., Hirayama Y., Imai N., Ishiyama H., Jeong S. C., Miyatake H., Choi S., Song J., Clement E., de France G., Navin A., Rejmund M., Schmitt C., Pollarolo G., Corradi L., Fioretto E., Montanari D., Niikura M., Suzuki D., Nishibata H., and Takatsu J.

Subjects
Physics, QC1-999
Abstract

The feasibility of the multi-nucleon transfer (MNT) reaction in the 136Xe +198Pt system was investigated for synthesizing neutron-rich heavy nuclei around mass number A∼200 of astrophysical interest. Identification of the projectile-like fragments (PLF’s) was successfully performed by using VAMOS++ spectrometer. The isotopic distributions of the PLF’s produced by two-proton stripping and pickup reactions were compared with each other, demonstrating the properties of the MNT reactions observed in the present system. The two-proton pickup channels strongly populated than the twoproton stripping channels were observed. The isotopic distributions for different total kinetic energy loss (TKEL) ranges are also discussed. The overall enhancement of the strength of the two-proton pickup compared with the two-proton stripping appears to be related to the MNT reactions with relatively moderate energy dissipation.

Published
2014
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12. Present Status of KEK Isotope Separation System

Author

Hirayama Y., Jeong S.C., Watanabe Y.X., Imai N., Ishiyama H., Miyatake H., Oyaizu M., Kim Y.H., Mukai M., Sonoda T., Wada M., Huyse M., Kudryavtsev Yu., and Van Duppen P.

Subjects
Physics, QC1-999
Abstract

KISS (KEK Isotope Separation System) has been constructed at Nishina Re-search Center (NRC) of RIKEN to study the decay properties of heavy neutron-rich iso-topes with mass number around A∼200 along the neutron magic number of N = 126 for the astrophysical interest. The isotopes of interest will be produced by multi-nucleon transfer reactions in neutron-rich heavy ion collisions (e.g. 136Xe projectile on 198Pt target). KISS consists of a gas-cell system for thermalizing (stopping and neutralizing) and fast-transporting reaction products to the gas cell exit hole, a laser system for the res-onant ionization, and a mass-separator system followed by a detection system for the decay spectroscopy. KISS will allow us to study unknown isotopes produced in weak re-action channels under low background conditions. The off-line test of the KISS has been finished. As a next step, on-line test experiments have been performed to investigate the overall efficiency and selectivity of the system as a function of the injected 56Fe beam intensity from the RIKEN Ring Cyclotron (RRC).

Published
2014
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14. First high-precision direct determination of the atomic mass of a superheavy nuclide

Author

Schury, P., Niwase, T., Wada, M., Brionnet, P., Chen, S., Hashimoto, T., Haba, H., Hirayama, H., Hou, D. S., Iimura, S., Ishiyama, H., Ishizawa, S., Ito, Y., Kaji, D., Kimura, S., Koura, H., Liu, J. J., Miyatake, H., Moon, J. -Y., Morimoto, K., Morita, K., Nagae, D., Rosenbusch, M., Takamine, A., Watanabe, Y. X., Wollnik, H., Xian, W., and Yan, S. X.

Subjects
Nuclear Experiment
Abstract

We present the first direct measurement of the atomic mass of a superheavy nuclide. Atoms of $^{257}$Db ($Z$=105) were produced online at the RIKEN Nishina Center for Accelerator-Based Science using the fusion-evaporation reaction $^{208}$Pb($^{51}$V, 2n)$^{257}$Db. The gas-filled recoil ion separator GARIS-II was used to suppress both the unreacted primary beam and some transfer products, prior to delivering the energetic beam of $^{257}$Db ions to a helium gas-filled ion stopping cell wherein they were thermalized. Thermalized $^{257}$Db$^{3+}$ ions were then transferred to a multi-reflection time-of-flight mass spectrograph for mass analysis. An alpha particle detector embedded in the ion time-of-flight detector allowed disambiguation of the rare $^{257}$Db$^{3+}$ time-of-flight detection events from background by means of correlation with characteristic $\alpha$-decays. The extreme sensitivity of this technique allowed a precision atomic mass determination from 11 events. The mass excess was determined to be $100\,063(231)_\textrm{stat}(132)_\textrm{sys}$~keV/c$^2$. Comparing to several mass models, we show the technique can be used to unambiguously determine the atomic number as $Z$=105 and should allow similar evaluations for heavier species in future work., Comment: Submitted to PRC as Rapid Comm., 5 pages, 4 figures

Published
2020
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17. Mass measurements of neutron-rich A≈90 nuclei constrain element abundances

Author

Xian, W., primary, Chen, S., additional, Nikas, S., additional, Rosenbusch, M., additional, Wada, M., additional, Ishiyama, H., additional, Hou, D., additional, Iimura, S., additional, Nishimura, S., additional, Schury, P., additional, Takamine, A., additional, Yan, S., additional, Browne, F., additional, Doornenbal, P., additional, Flavigny, F., additional, Hirayama, Y., additional, Ito, Y., additional, Kimura, S., additional, Kojima, T. M., additional, Lee, J., additional, Liu, J., additional, Miyatake, H., additional, Michimasa, S., additional, Moon, J. Y., additional, Naimi, S., additional, Niwase, T., additional, Sonoda, T., additional, Suzuki, D., additional, Watanabe, Y. X., additional, Werner, V., additional, Wimmer, K., additional, and Wollnik, H., additional

Published
2024
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21. Application of spin polarized 19O beam to the study of oxygen motion in solid oxide fuel cell materials

Author

Otani, Y., Mihara, M., Matsuta, K., Fukuda, M., Wakabayashi, R., Okimoto, N., Fukutome, M., Kimura, Y., Takayama, G., Izumikawa, T., Noguchi, N., Ogose, M., Sato, M., Takatsu, K., Ohtsubo, T., Nishimura, D., Takahashi, H., Sugawara, S., Gladkov, A., Ishiyama, H., Kitagawa, A., Sato, S., Momota, S., Okumura, H., Moriguchi, T., Ozawa, A., Kaname, N., and Yano, A.

Published
2021
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22. Development of a resonant laser ionization gas cell for high-energy, short-lived nuclei

Author

Sonoda, T., Wada, M., Tomita, H., Sakamoto, C., Takatsuka, T., Furukawa, T., Iimura, H., Ito, Y., Kubo, T., Matsuo, Y., Mita, H., Naimi, S., Nakamura, S., Noto, T., Schury, P., Shinozuka, T., Wakui, T., Miyatake, H., Jeong, S., Ishiyama, H., Watanabe, Y. X., Hirayama, Y., Okada, K., and Takamine, A.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

A new laser ion source configuration based on resonant photoionization in a gas cell has been developed at RIBF RIKEN. This system is intended for the future PArasitic RI-beam production by Laser Ion-Source (PALIS) project which will be installed at RIKEN's fragment separator, BigRIPS. A novel implementation of differential pumping, in combination with a sextupole ion beam guide (SPIG), has been developed. A few small scroll pumps create a pressure difference from 1000 hPa - 10^-3 Pa within a geometry drastically miniaturized compared to conventional systems. This system can utilize a large exit hole for fast evacuation times, minimizing the decay loss for short-lived nuclei during extraction from a buffer gas cell, while sufficient gas cell pressure is maintained for stopping high energy RI-beams. In spite of the motion in a dense pressure gradient, the photo-ionized ions inside the gas cell are ejected with an assisting force gas jet and successfully transported to a high-vacuum region via SPIG followed by a quadrupole mass separator. Observed behaviors agree with the results of gas flow and Monte Carlo simulations.

Published
2012
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23. First direct mass measurement for neutron-rich Mo112 with the new ZD-MRTOF mass spectrograph system

Author

Hou, D. S., primary, Takamine, A., additional, Rosenbusch, M., additional, Xian, W. D., additional, Iimura, S., additional, Chen, S. D., additional, Wada, M., additional, Ishiyama, H., additional, Schury, P., additional, Niu, Z. M., additional, Liang, H. Z., additional, Yan, S. X., additional, Doornenbal, P., additional, Hirayama, Y., additional, Ito, Y., additional, Kimura, S., additional, Kojima, T. M., additional, Korten, W., additional, Lee, J., additional, Liu, J. J., additional, Liu, Z., additional, Michimasa, S., additional, Miyatake, H., additional, Moon, J. Y., additional, Naimi, S., additional, Nishimura, S., additional, Niwase, T., additional, Sonoda, T., additional, Suzuki, D., additional, Watanabe, Y. X., additional, Wimmer, K., additional, and Wollnik, H., additional

Published
2023
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28. Discovery of New Isotope U241 and Systematic High-Precision Atomic Mass Measurements of Neutron-Rich Pa-Pu Nuclei Produced via Multinucleon Transfer Reactions

Author

Niwase, T., primary, Watanabe, Y. X., additional, Hirayama, Y., additional, Mukai, M., additional, Schury, P., additional, Andreyev, A. N., additional, Hashimoto, T., additional, Iimura, S., additional, Ishiyama, H., additional, Ito, Y., additional, Jeong, S. C., additional, Kaji, D., additional, Kimura, S., additional, Miyatake, H., additional, Morimoto, K., additional, Moon, J.-Y., additional, Oyaizu, M., additional, Rosenbusch, M., additional, Taniguchi, A., additional, and Wada, M., additional

Published
2023
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29. First direct mass measurement for neutron-rich Mo 112 with the new ZD-MRTOF mass spectrograph system

Author

RIKEN Nishina Center for Accelerator-Based Science, China Scholarship Council, Japan Society for the Promotion of Science, Science and Technology Facilities Council (UK), Royal Society (UK), Research Grants Council (Hong Kong), National Natural Science Foundation of China, Hou, D. S. [0000-0001-5394-6885], Hou, D. S., Takamine, A., Rosenbusch, M., Xian, W. D., Iimura, S., Chen, S. D., Wada, M., Ishiyama, H., Schury, P., Niu, Z. M., Liang, H. Z., Yan, S. X., Doornenbal, P., Hirayama, Y., Ito, Y., Kimura, S., Kojima, T. M., Korten, W., Lee, J., Liu, J. J., Liu, Z., Michimasa, S., Miyatake, H., Moon, J. Y., Naimi, S., Nishimura, S., Niwase, T., Sonoda, T., Suzuki, D., Watanabe, Y. X., Wimmer, K., Wollnik, H., RIKEN Nishina Center for Accelerator-Based Science, China Scholarship Council, Japan Society for the Promotion of Science, Science and Technology Facilities Council (UK), Royal Society (UK), Research Grants Council (Hong Kong), National Natural Science Foundation of China, Hou, D. S. [0000-0001-5394-6885], Hou, D. S., Takamine, A., Rosenbusch, M., Xian, W. D., Iimura, S., Chen, S. D., Wada, M., Ishiyama, H., Schury, P., Niu, Z. M., Liang, H. Z., Yan, S. X., Doornenbal, P., Hirayama, Y., Ito, Y., Kimura, S., Kojima, T. M., Korten, W., Lee, J., Liu, J. J., Liu, Z., Michimasa, S., Miyatake, H., Moon, J. Y., Naimi, S., Nishimura, S., Niwase, T., Sonoda, T., Suzuki, D., Watanabe, Y. X., Wimmer, K., and Wollnik, H.

Abstract

The atomic masses of Ag111,113, Pd111-113, Rh111-113, Ru111-113, and Mo111,112 have been measured during the online commissioning experiments of the ZeroDegree multi-reflection time-of-flight Mass Spectrograph (ZD MRTOF-MS) at the RIKEN RI beam factory. The mass of Mo112 has been determined. For the previously known masses, a good agreement between our results and the 2020 Atomic Mass Evaluation has been observed in most cases. The determined two-neutron separation energies for Mo isotopes up to N=70 show a smooth trend. In this work, the performed experiment and analysis procedure are presented. The theoretical interest in the measured region is highlighted, and the results are discussed in terms of the various mass surface formulas including the new mass data. Furthermore, a comparison between our results and global theoretical mass models is given, and we provide a benchmark for results from a Bayesian machine learning algorithm for future mass extrapolation.

Published
2023

34. The new MRTOF mass spectrograph following the ZeroDegree spectrometer at RIKEN’s RIBF facility

Author

Rosenbusch, M., primary, Wada, M., additional, Chen, S., additional, Takamine, A., additional, Iimura, S., additional, Hou, D., additional, Xian, W., additional, Yan, S., additional, Schury, P., additional, Hirayama, Y., additional, Ito, Y., additional, Ishiyama, H., additional, Kimura, S., additional, Kojima, T., additional, Lee, J., additional, Liu, J., additional, Michimasa, S., additional, Miyatake, H., additional, Moon, J.Y., additional, Mukai, M., additional, Naimi, S., additional, Nishimura, S., additional, Niwase, T., additional, Sonoda, T., additional, Watanabe, Y.X., additional, and Wollnik, H., additional

Published
2023
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35. Study of the N=32 and N=34 Shell Gap for Ti and V by the First High-Precision Multireflection Time-of-Flight Mass Measurements at BigRIPS-SLOWRI

Author

Iimura, S., primary, Rosenbusch, M., additional, Takamine, A., additional, Tsunoda, Y., additional, Wada, M., additional, Chen, S., additional, Hou, D. S., additional, Xian, W., additional, Ishiyama, H., additional, Yan, S., additional, Schury, P., additional, Crawford, H., additional, Doornenbal, P., additional, Hirayama, Y., additional, Ito, Y., additional, Kimura, S., additional, Koiwai, T., additional, Kojima, T. M., additional, Koura, H., additional, Lee, J., additional, Liu, J., additional, Michimasa, S., additional, Miyatake, H., additional, Moon, J. Y., additional, Naimi, S., additional, Nishimura, S., additional, Niwase, T., additional, Odahara, A., additional, Otsuka, T., additional, Paschalis, S., additional, Petri, M., additional, Shimizu, N., additional, Sonoda, T., additional, Suzuki, D., additional, Watanabe, Y. X., additional, Wimmer, K., additional, and Wollnik, H., additional

Published
2023
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38. Study of collisions of 136Xe + 198Pt for the KEK isotope separator

Author

Watanabe, Y.X., Hirayama, Y., Imai, N., Ishiyama, H., Jeong, S.C., Miyatake, H., Clement, E., de France, G., Navin, A., Rejmund, M., Schmitt, C., Pollarolo, G., Corradi, L., Fioretto, E., Montanari, D., Choi, S.H., Kim, Y.H., Song, J.S., Niikura, M., Suzuki, D., Nishibata, H., and Takatsu, J.

Published
2013
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43. Comparison of low-dose-rate brachytherapy versus radical prostatectomy in patients with intermediate-risk prostate cancer: A propensity-matched multi-institutional study

Author

Tsumura, H., primary, Tanaka, N., additional, Oguchi, T., additional, Owari, T., additional, Nakai, Y., additional, Asakawa, I., additional, Iijima, K., additional, Kato, H., additional, Hashida, I., additional, Tabata, K., additional, Satoh, T., additional, and Ishiyama, H., additional

Published
2022
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45. α -decay-correlated mass measurement of Ra206,207g,m using an α -TOF detector equipped multireflection time-of-flight mass spectrograph system

Author

Niwase, T., primary, Wada, M., additional, Schury, P., additional, Brionnet, P., additional, Chen, S. D., additional, Hashimoto, T., additional, Haba, H., additional, Hirayama, Y., additional, Hou, D. S., additional, Iimura, S., additional, Ishiyama, H., additional, Ishizawa, S., additional, Ito, Y., additional, Kaji, D., additional, Kimura, S., additional, Liu, J., additional, Miyatake, H., additional, Moon, J. Y., additional, Morimoto, K., additional, Morita, K., additional, Nagae, D., additional, Rosenbusch, M., additional, Takamine, A., additional, Tanaka, T., additional, Watanabe, Y. X., additional, Wollnik, H., additional, Xian, W., additional, and Yan, S. X., additional

Published
2021
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47. First high-precision direct determination of the atomic mass of a superheavy nuclide

Author

Schury, P., primary, Niwase, T., additional, Wada, M., additional, Brionnet, P., additional, Chen, S., additional, Hashimoto, T., additional, Haba, H., additional, Hirayama, Y., additional, Hou, D. S., additional, Iimura, S., additional, Ishiyama, H., additional, Ishizawa, S., additional, Ito, Y., additional, Kaji, D., additional, Kimura, S., additional, Koura, H., additional, Liu, J. J., additional, Miyatake, H., additional, Moon, J.-Y., additional, Morimoto, K., additional, Morita, K., additional, Nagae, D., additional, Rosenbusch, M., additional, Takamine, A., additional, Watanabe, Y. X., additional, Wollnik, H., additional, Xian, W., additional, and Yan, S. X., additional

Published
2021
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49. Spin-polarization of radioactive 123Ing.s. by the tilted-foil method

Author

Hirayama, Y., Mihara, M., Watanabe, Y. X., Jeong, S. C., Imai, N., Matsuta, K., Miyatake, H., Hashimoto, T., Ishiyama, H., Ichikawa, S., Ishii, T., Izumikawa, T., Katayama, I., Kawakami, H., Nishinaka, I., Nishio, K., Makii, H., Mitsuoka, S., Momota, S., Osa, A., Otokawa, Y., Sato, T. K., and Wakabayashi, Y.

Published
2011
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