Growth processes of zircon crystals in a granitic magma chamber, variation in U-Pb age, titanium concentration, and Th/U in relation to internal texture

Yuguchi, Takashi*; Endo, Kyoka*; Suzuki, Satoshi*; Ogita, Yasuhiro; Sakata, Shuhei*; Yokoyama, Tatsunori; Imura, Takumi*; Ono, Takeshi*; Sasao, Eiji

Lithos, 494-495, p.107909_1 - 107909_14, 2025/02

https://doi.org/10.1016/j.lithos.2024.107909

This study described the growth characteristics of zircon crystals in the Kuki granite from the Kitakami Mountains in northeastern Japan as the key for elucidating granitic magma chamber processes. Using two approaches, analyses based on multiple sections of separated zircon crystals and thin-section-based zircon crystal analyses, we determined the characteristics of the 3D internal structure of the crystals, variations in U-Pb age, Ti concentrations, and Th/U in relation to crystal texture, and the crystallization sequence between zircon crystals and other minerals within the magma chamber. The textures, which occupy a large proportion of zircon, comprise low luminescence homogeneous cores (LLCs) and oscillatory zoning (OZ). The 3D distribution of the zircon internal structure can be classified into three types: Type 1 zircon comprising LLCs and the surrounding OZ and Types 2 and 3 zircon crystals composed entirely of OZ from the cores to the rims and characterized by brightness and darkness cores, respectively. LLC and OZ grew at temperatures from approximately 900 to 800C and 850 to 700C, respectively, and LLC has a higher Th/U than that of OZ, indicating that fractional crystallization progression as the magma chamber cooled resulted in the transition from LLC to OZ. In the progression of fractional crystallization, the diffusion rate deceleration with decreasing magma temperatures triggered the transition from interfacial reaction-controlled growth producing LLC to diffusion-controlled growth producing OZ. In the thin-section analysis, zircon crystals which contained in different minerals are characterized by different Th/U values. The variation in Th/U and the crystallization temperature of zircon crystals considering the surrounding minerals can be used to elucidate the differentiation and mineral crystallization in magma chamber processes over a wide range of temperature conditions.

U-Pb dating of calcite using LA-ICP-MS; Instrumental setup for non-matrix-matched age dating and determination of analytical areas using elemental imaging

Yokoyama, Tatsunori; Kimura, Junichi*; Mitsuguchi, Takehiro; Danhara, Toru*; Hirata, Takafumi*; Sakata, Shuhei*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; Miyazaki, Takashi*; et al.

Geochemical Journal, 52(6), p.531 - 540, 2018/12

https://doi.org/10.2343/geochemj.2.0541

Development of millimeter-wave planar antennas using low-loss materials

Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Shimazu, Hiroshi*; Sakata, Eiji*

Japanese Journal of Applied Physics, 49(10), p.106506_1 - 106506_5, 2010/10

https://doi.org/10.1143/JJAP.49.106506

As the importance of advanced millimeter-wave diagnostics increases, the fabrications of high-performance devices and components become essential. This paper describes the development of millimeter-wave planar antennas using low-loss fluorine substrates. The problems to be solved for the present purpose are the low degree of adhesion between copper foil and fluorine substrate and the accuracy of device pattern using conventional fabrication techniques. In order to solve these problems, surface treatment of fluorine films and a fabrication method using Electro-Fine-Forming (EF2) are proposed. In order to confirm the performance of the treated films, microstrip lines (MSL) and the planar patch antennas with low-sidelobe level in E-plane are designed and fabricated on the conventional fluorine substrates and on the grafted-PTFE (Polytetrafluoroethylene) films.

Development of planar devices using low-loss materials

Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Sakata, Eiji*

Proceedings of 11th IEEE International Conference on Communication Technology (ICCT 2008), 3 Pages, 2008/11

As the importance of advanced microwave and millimeter-wave diagnostics increases, the fabrications of high-performance planar devices become essential. This paper describes the development of planar devices such as antennas using low-loss fluorine materials. The problems to be solved for the present purpose are the low degree of adhesion between copper foil and fluorine substrate and the accuracy of device pattern using conventional fabrication techniques. In order to solve these problems, surface treatment of fluorine films and a fabrication method using Electro-Fine-Forming (EF2) are proposed. The peel adhesion strength between the metal and the fluorine films and the value of dielectric constant of the fluorine films before and after grafting are reported. In order to confirm the performance of the treated films, microstrip lines are fabricated on the conventional fluorine substrates and on the grafted-PTFE (Polytetrafluoroethylene) films. The prototype antennas using fluorine substrates with EF2 fabrication technique are also introduced.

Advanced fabrication method of planar components for plasma diagnostics

Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Shen, Z.*; Yang, L.*; Domier, C. W.*; Luhmann, N. C. Jr.*; Sakata, Eiji*

Plasma and Fusion Research (Internet), 2, p.S1042_1 - S1042_4, 2007/11

https://doi.org/10.1585/pfr.2.S1042

As the importance of plasma imaging diagnostics increases, the fabrication of high performance millimeter-wave planar components becomes essential. This paper describes the development of high performance millimeter-wave planar components such as antennas and filters using low-loss fluorine substrate. The problems to be solved are low degree of adhesion between copper foil and fluorine substrate and shape of antenna pattern. In order to solve the problems, surface treatment of fluorine films and a fabrication method using Electro Fine Forming (EF2) are utilized.

Development of low-loss millimeter-wave antennas on fluorine substrate using electro-fine-forming fabrication

Ito, Naoki*; Mase, Atsushi*; Seko, Noriaki; Tamada, Masao; Sakata, Eiji*; Kogi, Yuichiro*

Proceedings of Asia-Pacific Microwave Conference 2006 (APMC 2006), Vol.1 (CD-ROM), p.2031 - 2033, 2006/12

Polytetrafluoroethylene (PTFE) has many desirable properties for substrates of millimeter-wave planar antennas such as low dielectric constant and loss tangent. However, it has weak adhesion to various metals. Surface treatment of PTFE via radiation-induced graft polymerization was carried out to improve the adhesion. The peel adhesion strength of the PTFE/Cu was attained to be 10.3 N/cm by the treatment. The dielectric function of grafted-PTFE remained almost unchanged after the graft polymerization. The design and fabrication of millimeter-wave antennas on the treated PTFE substrates have been performed using electro-fine-forming (EF2) technology.

Anomalous spin density distribution in CeB

Saito, Masahiro*; Okada, Noriko*; Nishibori, Eiji*; Takagiwa, Hiroyuki*; Yokoo, Tetsuya*; Nishi, Masakazu*; Kakurai, Kazuhisa; Kunii, Satoru*; Takata, Masaki*; Sakata, Makoto*; et al.

Journal of the Physical Society of Japan, 71(10), p.2369 - 2372, 2002/10

https://doi.org/10.1143/JPSJ.71.2369

no abstracts in English

The First loading fuel elements and power-up for JRR-2

JRR-2 Control Office; Kambara, Toyozo; Shoda, Katsuhiko; Hirata, Yutaka; Shoji, Tsutomu; Kohayakawa, Toru; Morozumi, Minoru; Kambayashi, Yuichiro; Shitomi, Hajimu; Kokanezawa, Takashi; et al.

JAERI 1027, 57 Pages, 1962/09

JAERI-1027.pdf:4.76MB

no abstracts in English

Four events of zircon growth with specific mechanisms, crystallization temperatures and U-Pb ages; Implication to the "spatiotemporal" formation process of a granitic pluton, the Toki granite, Central Japan

Yuguchi, Takashi*; Iwano, Hideki*; Kato, Takenori*; Sakata, Shuhei*; Hattori, Kentaro*; Hirata, Takafumi*; Sueoka, Shigeru; Danhara, Toru*; Ishibashi, Masayuki; Sasao, Eiji; et al.

no journal, , 

Zircon growth collected from a granitic pluton shows four (1st - 4th) events with specific mechanisms, crystallization temperatures and U-Pb ages, revealing the sequential formation process from intrusion through emplacement to crystallization / solidification. The events are recognized by: (1) internal structure of zircon based on the cathodoluminescence observation, (2) crystallization temperatures by the Ti-in-zircon thermometer in the internal structure and (3) U-Pb ages in the internal structure.

Development of low-loss millimeter-wave antennas using electro-fine-forming fabrication

Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Sakata, Eiji*

no journal, , 

no abstracts in English