Role of resonance states of muonic molecule in muon catalyzed fusion

Okutsu, Kenichi*; Yamashita, Takuma*; Kino, Yasushi*; Miyashita, Konan*; Yasuda, Kazuhiro*; Oka, Toshitaka; Okada, Shinji*; Sato, Motoyasu*

JJAP Conference Proceedings (Internet), 9, p.011003_1 - 011003_7, 2023/00

https://doi.org/10.56646/jjapcp.9.0_011003

Muon catalyzed fusion (CF) is a cyclic reaction where a negatively charged muon itself acts like a catalyst of nuclear fusion between hydrogen isotopes. In the CF reaction, muon transfer from deuteron to triton and muonic molecular formation are rate-limiting processes. In this work, we have investigated the role of resonance states of muonic molecule in the CF which affects the muonic deuterium atom population. Solving simultaneous rate equations numerically by the fourth-order Runge-Kutta method, we determined the muonic molecular formation rate so that the number of fusion events reproduces a latest experimental result. It is revealed that the resonance states play a role to enhance the fusion rate by accelerating the de-excitation of the muonic atoms.

Time evolution calculation of muon catalysed fusion; Emission of recycling muons from a two-layer hydrogen film

Yamashita, Takuma*; Okutsu, Kenichi*; Kino, Yasushi*; Nakashima, Ryota*; Miyashita, Konan*; Yasuda, Kazuhiro*; Okada, Shinji*; Sato, Motoyasu*; Oka, Toshitaka; Kawamura, Naritoshi*; et al.

Fusion Engineering and Design, 169, p.112580_1 - 112580_5, 2021/08

https://doi.org/10.1016/j.fusengdes.2021.112580

A muon () having 207 times larger mass of electron and the same charge as the electron has been known to catalyze a nuclear fusion between deuteron (d) and triton (t). These two nuclei are bound by and form a muonic hydrogen molecular ion, dt. Due to the short inter-nuclear distance of dt, the nuclear fusion, d +t + n + 17.6 MeV, occurs inside the molecule. This reaction is called muon catalyzed fusion (CF). Recently, the interest on CF is renewed from the viewpoint of applications, such as a source of high-resolution muon beam and mono-energetic neutron beam. In this work, we report a time evolution calculation of CF in a two-layered hydrogen isotope target.

Deexcitation dynamics of muonic atoms revealed by high-precision spectroscopy of electronic X rays

Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.

Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07

https://doi.org/10.1103/PhysRevLett.127.053001

We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic and X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the -shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.

XAFS measurement of simulated waste glass samples (Borosilicate glass including vanadium)

Nagai, Takayuki; Kobayashi, Hidekazu; Sasage, Kenichi; Ayame, Yasuo; Okamoto, Yoshihiro; Shiwaku, Hideaki; Matsuura, Haruaki*; Uchiyama, Takafumi*; Okada, Yukiko*; Nezu, Atsushi*; et al.

JAEA-Research 2016-015, 52 Pages, 2016/11

JAEA-Research-2016-015.pdf:37.48MB

The local structure of waste elements in simulated waste glasses including V was estimated by using synchrotron XAFS measurement in this study. The results are as follows. (1) V has a high possibility which exists in the glass phase in the case of frit, and V can regard both samples as stable 4 coordination structure. (2) Zn, Ce, Nd, Zr, and Mo exist in the glass phase, and the difference is admitted by the percentage of Ce(III) and Ce(IV) by the composition. (3) Ru is separated from the glass phase as RuO crystalline, both of metal and oxide exist in Rh, and Pd is separated out as metal. (4) It was confirmed that the regularity of the local structure of Zr and Mo in the molten glasses retreats as a result of the XAFS measurement at high temperature. (5) The XAFS measurement of molten glasses were performed at 1200C, so it would be possible to acquire excellent data by improving the shapes of the sample cell.

Irradiation history of Itokawa regolith material deduced from noble gases in the Hayabusa samples

Nagao, Keisuke*; Okazaki, Ryuji*; Nakamura, Tomoki*; Miura, Yayoi*; Osawa, Takahito; Bajo, Kenichi*; Matsuda, Shintaro*; Ebihara, Mitsuru*; Ireland, T.*; Kitajima, Fumio*; et al.

Science, 333(6046), p.1128 - 1131, 2011/08

https://doi.org/10.1126/science.1207785

A steroid surface materials record regolith processes and a history of cosmic-ray irradiation. Noble gas isotopes in three rocky grains from Itokawa have been determined. High concentrations of solar He, Ne, and Ar, as high as those in lunar soils, are released at variable temperatures from each sample. The isotopic compositions are essentially identical to those of solar wind but distinguishable in He relative abundance. These noble gas characteristics can be explained by repeated implantation and preferential loss of solar He by removal of weathered He-rich rim on the grain surface through friction among regolith grains on Itokawa. Residence time of regolith materials on Itokawa is alculated to be shorter than 10 Myr, suggesting that regolith materials of small asteroids would escape easily to space.

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

Measurement of neutral mesons in + collisions at = 200 GeV and scaling properties of hadron production

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03

https://doi.org/10.1103/PhysRevD.83.052004

The PHENIX experiment at RHIC has measured the invariant differential cross section for production of , , and mesons in collisions at = 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters, and , determining the high and characterizing the low regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.

Present status of JAEA-Tokai tandem accelerator

Matsuda, Makoto; Takeuchi, Suehiro; Tsukihashi, Yoshihiro; Hanashima, Susumu; Abe, Shinichi; Osa, Akihiko; Ishizaki, Nobuhiro; Tayama, Hidekazu; Nakanoya, Takamitsu; Kabumoto, Hiroshi; et al.

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan, p.275 - 277, 2006/00

no abstracts in English

X-ray diffraction of graphite-diamond transformation using various catalysts under high pressures and high temperatures

Utsumi, Wataru; Okada, Taku; Taniguchi, Takashi*; Funakoshi, Kenichi*; Kikegawa, Takumi*; Hamaya, Nozomu; Shimomura, Osamu

Journal of Physics; Condensed Matter, 16(14), p.S1017 - S1026, 2004/04

https://doi.org/10.1088/0953-8984/16/14/011

The graphite-diamond transformation was investigated using in-situ time-resolved X-ray diffraction experiments with a MgO dissolved aqueous fluid as the diamond forming catalyst under conditions of 6.6-8.8 GPa and 1400-1835C. Experiments were conducted using a 180-ton DIA-type cubic-anvil apparatus installed on the beamline BL14B1 at SPring-8, a third-generation synchrotron radiation facility in Japan. By analyzing the kinetic data using the JMAK rate equation, it was clarified that altering the pressure-temperature conditions drastically changes the nucleation and growth process of diamond.

Viscosity change and structural transition of molten Fe at 5 GPa

Terasaki, Hidenori*; Kato, Takumi*; Urakawa, Satoru*; Funakoshi, Kenichi*; Sato, Kiminori*; Suzuki, Akio*; Okada, Taku

Geophysical Research Letters, 29(8), p.68_1 - 68_3, 2002/05

The in situ viscosity measurements of the pure molten Fe under high pressures were made by falling sphere X-ray radiography method. Viscosity coefficients at about 2000 K were 15-24 mPa s at 2.7-5.0 GPa, and 4-9 mPa s at 5.0-7.0 GPa. Drastic decrease was found at around 5 GPa, at which stable solid phase below the melting temperatures change from delta (bcc) to gamma (fcc) phases. The observation indicates the possibility that the structural change in the molten Fe occurs in a narrow pressure interval (1 GPa) at the similar condition with the phase transformation in the solid.