Characterization of the thorium-229 defect structure in CaF crystals

Takatori, Sayuri*; Pimon, M.*; Pollitt, S.*; Bartokos, M.*; Beeks, K.*; Grneis, A.*; Hiraki, Takahiro*; Homma, Tetsuo*; Hosseini, N.*; Leitner, A.*; et al.

New Journal of Physics (Internet), 27(4), p.043024_1 - 043024_10, 2025/04

https://doi.org/10.1088/1367-2630/adce22

Recent reports on laser excitation of the low-energy thorium-229 (Th) nuclear isomeric state in calcium fluoride single crystals render this system a promising candidate for a solid-state nuclear clock. However, experimental characterization of the microscopic ion arrangement around the doped Th and its electronic charge state, crucial for the precise control of the clock transition and assessing the solid-state clock's performance, remains an unresolved task. This study uses X-ray absorption fine structure spectroscopy of Th:CaF to investigate the charge state and coordination environment of doped Th. The results indicate that Th is doped with a 4+ valence at the substitutional site of the Ca ion, with charge compensated provided by two F ions located at interstitial sites adjacent to Th.

Simultaneous measurements of superradiance at multiple wavelength from helium excited states, 2; Analysis

Ohae, Chiaki*; Harries, J.; Iwayama, Hiroshi*; Kawaguchi, Kentaro*; Kuma, Susumu*; Miyamoto, Yuki*; Nagasono, Mitsuru*; Nakajima, Kyo*; Nakano, Itsuo*; Shigemasa, Eiji*; et al.

Journal of the Physical Society of Japan, 85(3), p.034301_1 - 034301_10, 2016/03

https://doi.org/10.7566/JPSJ.85.034301

Precision measurement of the electric quadrupole moment of Al and determination of the effective proton charge in the sd-shell

De Rydt, M.*; Neyens, G.*; Asahi, Koichiro*; Balabanski, D. L.*; Daugas, J. M.*; Depuydt, M.*; Gaudefroy, L.*; Grvy, S.*; Hasama, Yuka*; Ichikawa, Yuichi*; et al.

Physics Letters B, 678(4), p.344 - 349, 2009/07

https://doi.org/10.1016/j.physletb.2009.06.043

no abstracts in English

Electric quadrupole moment measurement using a new RF-application system

Nagae, Daisuke; Takemuara, Makoto*; Ueno, Hideki*; Kameda, Daisuke*; Asahi, Koichiro*; Yoshimi, Akihiro*; Sugimoto, Takashi*; Nagatomo, Takashi*; Kobayashi, Yoshio*; Uchida, Makoto*; et al.

no journal, , 

An electric quadrupole moment ( moment) is sensitive to collective aspects of nuclear structure. In the -moment measurement for unstable nuclei, we employ the -detected nuclear-quadrupole resonance method. In this method, we need to supply resonance frequencies, where denotes the nuclear spin. We have developed a new RF-application system to induced all of the transitions. The application of the frequencies may be pursued in two different ways; the sequential RF pulse method and the mixed-wave RF pulse method. We confirmed the reversal of polarization for the both methods, from measurements of -ray asymmetry change for polarized B. Using this system, the moments of Al have been measured to be mb and mb by the sequential RF pulse method.