Birchite CdCu(PO)SO 5HO as a model antiferromagnetic spin-1/2 Heisenberg - chain

Fujihara, Masayoshi; Jeschke, H. O.*; Morita, Katsuhiro*; Kuwai, Tomohiko*; Koda, Akihiro*; Okabe, Hirotaka*; Matsuo, Akira*; Kindo, Koichi*; Mitsuda, Setsuo*

Physical Review Materials (Internet), 6(11), p.114408_1 - 114408_8, 2022/11

https://doi.org/10.1103/PhysRevMaterials.6.114408

= 1/2 Heisenberg - chain antiferromagnets have been investigated extensively due to their exotic magnetic states. Here, we report the magnetic behavior of birchite CdCu(PO)SO5HO and its effective spin model. Experimental studies by magnetic susceptibility, magnetization, heat capacity, and SR measurements indicate the absence of long-range order down to 0.4 K. Theoretical studies reveal that birchite is a model compound for the - antiferromagnetic chain: the intrachain interactions and are antiferromagnetic and their magnitude is about 100 times larger than the interchain interactions. The magnitude of is two to three times larger than that of , thus the spin gap is expected to be only a few percent of that of . The temperature dependence of the specific heat shows a broad peak at about 1 K ( 0.036 ), which suggests the presence of a spin gap.

First direct mass measurements of nuclides around = 100 with a multireflection time-of-flight mass spectrograph

Ito, Yuta*; Schury, P.*; Wada, Michiharu*; Arai, Fumiya*; Haba, Hiromitsu*; Hirayama, Yoshikazu*; Ishizawa, Satoshi*; Kaji, Daiya*; Kimura, Sota*; Koura, Hiroyuki; et al.

Physical Review Letters, 120(15), p.152501_1 - 152501_6, 2018/04

https://doi.org/10.1103/PhysRevLett.120.152501

Masses of Es, Fm and the transfermium nuclei Md, and No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed neutron shell closure, have been directly measured using a multi-reflection time-of-flight mass spectrograph. The masses of Es and Md were measured for the first time. Using the masses of Md as anchor points for decay chains, the masses of heavier nuclei, up to Bh and Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter derived from three isotopic masses was updated with the new masses and corroborate the existence of the deformed neutron shell closure for Md and Lr.

Exotic hadrons from heavy ion collisions

Cho, S.*; Hyodo, Tetsuo*; Jido, Daisuke*; Ko, C. M.*; Lee, S. H.*; Maeda, Saori*; Miyahara, Kenta*; Morita, Kenji*; Nielsen, M.*; Onishi, Akira*; et al.

Progress in Particle and Nuclear Physics, 95, p.279 - 322, 2017/07

AA2016-0538.pdf:0.74MB

https://doi.org/10.1016/j.ppnp.2017.02.002

With upgraded detectors at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), it has become possible to measure hadrons beyond their ground states in high energy heavy ion collisions. Therefore, heavy ion collisions provide a new method for studying exotic hadrons that are either molecular states made of various hadrons or compact system consisting of muliquarks. Because their structures are related to the fundamental properties of Quantum Chromodynamics (QCD), studying exotic hadrons is currently one of the most active areas of research in hadron physics. The present review is a summary of the current understanding of a selected set of exotic candidate particles that can be potentially measured in heavy ion collisions.

First online multireflection time-of-flight mass measurements of isobar chains produced by fusion-evaporation reactions; Toward identification of superheavy elements via mass spectroscopy

Schury, P.*; Wada, Michiharu*; Ito, Yuta*; Kaji, Daiya*; Arai, Fumiya*; MacCormick, M.*; Murray, I.*; Haba, Hiromitsu*; Jeong, S.*; Kimura, Sota*; et al.

Physical Review C, 95(1), p.011305_1 - 011305_6, 2017/01

AA2016-0638.pdf:0.71MB

https://doi.org/10.1103/PhysRevC.95.011305

Using a multireflection time-of-flight mass spectrograph located after a gas cell coupled with the gas-filled recoil ion separator GARIS-II, the masses of several -decaying heavy nuclei were directly and precisely measured. The nuclei were produced via fusion-evaporation reactions and separated from projectilelike and targetlike particles using GARIS-II before being stopped in a helium-filled gas cell. Time-of-flight spectra for three isobar chains, Fr-Rn-At-Po, Fr- Rn-At-Po-Bi, and Fr-Rn-At, were observed. Precision atomic mass values were determined for Fr, Rn, and At. Identifications of Bi, Po, Rn, and At were made with N10 detected ions, representing the next step toward use of mass spectrometry to identify exceedingly low-yield species such as superheavy element ions.

Production of Db in the Cm(F,5)Db reaction and decay properties of Db and Lr

Haba, Hiromitsu*; Huang, M.*; Kaji, Daiya*; Kanaya, Jumpei*; Kudo, Yuki*; Morimoto, Koji*; Morita, Kosuke*; Murakami, Masashi*; Ozeki, Kazutaka*; Sakai, Ryutaro*; et al.

Physical Review C, 89(2), p.024618_1 - 024618_11, 2014/02

https://doi.org/10.1103/PhysRevC.89.024618

A Multi-reflection time-of-flight mass spectrograph for short-lived and super-heavy nuclei

Schury, P. H.*; Wada, Michiharu*; Ito, Yuta*; Naimi, S.*; Sonoda, Tetsu*; Mita, Koki*; Takamine, Aiko*; Okada, Kunihiro*; Wollnik, H.*; Chon, S.*; et al.

Nuclear Instruments and Methods in Physics Research B, 317(Part B), p.537 - 543, 2013/12

https://doi.org/10.1016/j.nimb.2013.06.025

A multi-reflection time-of-flight (MRTOF) mass spectrograph has been implemented at RIKEN to provide high-precision mass measurements of very short-lived nuclei. Of particular interest are mass measurements of r-process nuclei and trans-uranium nuclei. In such nuclei, the MRTOF can perform on par with or better than traditional Penning trap systems. We demonstrate that the MRTOF-MS is capable of accurately attaining relative mass precision of m/m 10 and describe it's utility with heavy, short-lived nuclei.

Data of heavy elements for light sources in EUV and XUV and for other applications

Koike, Fumihiro*; Funaba, Hisamichi*; Goto, Motoshi*; Kato, Daiji*; Kato, Takako*; Morita, Shigeru*; Murakami, Izumi*; Sakaue, Hiroyuki*; Sudo, Shigeru*; Suzuki, Chihiro*; et al.

AIP Conference Proceedings 1545, p.202 - 211, 2013/07

https://doi.org/10.1063/1.4815855

Atomic ionic states and transition properties of elements with atomic numbers Z ranging from 50 to 80 are discussed as these are important to the understanding of plasmas containing such heavy elements. As such, data productions and the current status of theoretical calculations in this field are discussed. Further, recent spectroscopic measurements and respective theoretical analyses for W, Gd, and Nd are provided.

New result in the production and decay of an isotope, 113 of the 113th element

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.

Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10

https://doi.org/10.1143/JPSJ.81.103201

An isotope of the 113th element, 113, was produced in a nuclear reaction with a Zn beam on a Bi target. We observed six consecutive decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of Db and Lr both in decay energies and decay times. This indicates that the present decay chain consisted of 113, Rg (Z = 111), Mt (Z = 109), Bh (Z = 107), Db (Z = 105), and Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope 113, of the 113th element.

Electronic absorption spectra of palladium(II) in concentrated nitric acid solutions

Fujii, Toshiyuki*; Egusa, Soichiro*; Uehara, Akihiro*; Kirishima, Akira*; Yamagishi, Isao; Morita, Yasuji; Yamana, Hajimu*

Journal of Radioanalytical and Nuclear Chemistry, 290(2), p.475 - 478, 2011/11

https://doi.org/10.1007/s10967-011-1284-7

Palladium complexation in concentrated nitric acid solutions was studied by UV/Vis absorption spectrophotometry. The ionic strength of the solutions was fixed to = 1, 3, or 5 M by mixing of HNO and HClO. The major palladium species were found to be Pd, PdNO, and Pd(NO). The formation constant of PdNO was determined to be = 1.32 ( = 1 M), 1.49 ( = 3 M), or 1.47 ( = 5 M), while that of Pd(NO) to be = 0.45 ( = 3 M) or 0.14 ( = 5 M).

Fluvial terrace and geomorphology in the Tokigawa (Shonaigawa) river basin since the middle Pleistocene

Tajikara, Masayoshi*; Yasue, Kenichi; Yanagida, Makoto*; Furusawa, Akira*; Tanaka, Norifumi*; Morita, Yoshimune*; Sugai, Toshihiko

Chirigaku Hyoron, 84(2), p.118 - 130, 2011/03

https://doi.org/10.4157/grj.84.118

Many papers reported that Quaternary climate and sea-level fluctuations have controlled riverbed elevation in the river basins in the northeastern Japan. However, in the southwestern Japan, such climatic-controlled riverbed fluctuations have not been reported, except a few reports based on uncertain chronological data. In this research, we investigated fluvial terraces along the Tokigawa river that flows through the low relief mountainous areas, and examined whether riverbed fluctuations similar to these in rivers in the northeastern Japan occurred in the river basin. We mapped fluvial terraces based on air photo analysis, and inferred the age and climate at the time of formation of these terraces based on C dating, tephra analysis, and pollen analysis. Based on results of these analyses, we concluded that the fluvial terraces in the river basin have been formed in consequence of the riverbed fluctuation linked to the climate change.