記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

We report on the selective production of the 2s metastable state of 390-MeV u(-1) H-like Ar17+ ions by the resonant coherent excitation (RCE). The RCE to the 2s state was achieved by using Stark mixing of n = 2 states under planar channeling conditions in a 1-mu m thick Si crystal. The population of the 2s state was quantitatively estimated from the ionization probability in a stripper foil installed 50 mm downstream of the crystal. The 2s population was found to be 0.05 of the total number of Ar17+ ions at the stripper. The result is in good agreement with a theoretical calculation performed with the density matrix approach.

DOI： 10.1088/0953-4075/48/14/144026

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記述言語：日本語   出版者・発行元：一般社団法人日本物理学会  

DOI： 10.11316/jpsgaiyo.70.1.0_639

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

We measured resonant coherent excitation of a 2s electron of 83.3 MeV/u Fe23+ ions planar-channeling in the ((2) over bar 20) plane of the silicon crystal. A silicon surface barrier detector (SSD) was used as a crystal target in order to obtain information on the ion trajectory in the channel since the energy deposit (Delta E) to the SSD gives information on the ion trajectories where the resonant transitions occur. For the low Delta E, i.e., near the channel center, optically allowed 2s-3p transitions were much stronger compared with other transitions. Increasing Delta E, i.e., increasing the amplitude of ion trajectory, the optically forbidden 2s-3s transition rapidly became strong. On the other hand, the optically forbidden 2s-3d transitions did not become strong as rapidly as 2s-3s transition. Furthermore, it was found that the transition energies to the n = 3 states changed with Delta E. The shifts of the transition energies were consistent with the estimation for the energy levels of the Stark-mixed n = 3 states depending on the distance from the channel center. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nimb.2013.05.072

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

We studied the anisotropy of Ly-alpha x-rays from H-like Ar17+ ions excited by polarization-controlled resonant coherent excitation. The effects of fine-structure depolarization on the 2p(1/2) and 2p(3/2) states were experimentally demonstrated as a reduction in anisotropy of decay radiation.

DOI： 10.1088/0031-8949/2013/T156/014061

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

We report our observation of the resonant fluorescence from highly charged uranium ions. Using the resonant coherent excitation (RCE) technique, the 2s-2p3/2 transition in 191.68 MeV/u Li-like U89+ ions was excited at 4.5 keV with a resonance width of 4.4 eV. The result demonstrated that the RCE can be applied to resonant fluorescence spectroscopy of high-Z ions up to uranium with high efficiency and resolution. © 2013 American Physical Society.

DOI： 10.1103/PhysRevA.87.060501

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSICAL SOC  

We report our observation of the resonant fluorescence from highly charged uranium ions. Using the resonant coherent excitation (RCE) technique, the 2s-2p(3/2) transition in 191.68 MeV/u Li-like U89+ ions was excited at 4.5 keV with a resonance width of 4.4 eV. The result demonstrated that the RCE can be applied to resonant fluorescence spectroscopy of high-Z ions up to uranium with high efficiency and resolution.

DOI： 10.1103/PhysRevA.87.060501

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/PhysRevA.85.020701

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/0031-8949/2011/T144/014010

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

We observed convoy electrons emitted from 416 MeV/u He-like Ar(16+) passing through a thin Si crystal under the condition of three-dimensional resonant coherent excitation (3D-RCE). The convoy electrons, which originate from electrons released from ions into the continuum by collisions with target atoms, emerged in the forward direction and formed a cusp-shaped peak in the energy distribution. We selectively controlled the population of the ground and excited states of ions traveling through the crystal by using 3D-RCE, where the 1s electron was excited to the 2p state by a periodic crystal field. Under the resonance condition, we found an enhancement of the convoy electrons with a narrowing in the energy distribution, which reflects the electron momentum distribution of the initial bound state of the excited ions.

DOI： 10.1088/0031-8949/2011/T144/014044

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記述言語：英語   掲載種別：学位論文（博士）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSICAL SOC  

We present an experimental demonstration of an ingenious technique to control the alignment of the atomic internal state in the x-ray region using a periodic crystal field. The alignment directions of Ar(16+) and Fe(24+) ions were readily controlled by selecting the array of atomic planes using three-dimensional resonant coherent excitation, and were probed via the anisotropy of the deexcitation x-ray emission. We applied this method to a double resonance experiment, and succeeded in controlling the population of the specific magnetic substate in a Lambda-type three-level configuration.

DOI： 10.1103/PhysRevLett.102.085502

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Physics Publishing  

We investigated resonant coherent excitation (RCE) of 445 MeV/u Li-like Ar15+ under the planar channeling and non-channeling conditions. The K-shell and L-shell excitations are observed as decreases in the survival fraction of the Ar15+ ions after passing through a thin Si crystal. RCE under the planar channeling condition provides the opportunity to study a strong static Stark effect on the Li-like system with K-shell or L-shell vacancy. Under the non-channeling conditions, the observed excitation energies and the reported theoretical calculations were in reasonable agreement. © 2009 IOP Publishing Ltd.

DOI： 10.1088/1742-6596/163/1/012094

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/PhysRevLett.101.113201

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記述言語：英語  

DOI： 10.1088/1742-6596/58/1/081

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

We observed resonant coherent excitation (RCE) of Is electron to the n = 2 states in 390 MeV/u Ar17+ ions passing through thin Si crystals of about I mu m in the {220} planar-channeling condition by measuring both the exit charge state and the exit angle of the emerged ions simultaneously in a list mode. The yield of the de-excitation X-rays from the Ar17+ ions was also measured. The thin crystal is suitable to study trajectory dependent RCE dynamics, because the exit angle of the high energy planar-channeling ion is uniquely related to the ion trajectory. From the de-excitation X-ray yield on resonance, we learned that RCE occurs with a fairly large probability within the traveling length of about I mu m, and a majority of the excited ions survive from ionization by the collisions with target electrons or nuclei. and de-excite into the ground state by emitting the X-rays. On the other hand, the observed resonance profile of the exit charge state is shallow and broadened by the Stark effect. We found that the ionization of the excited ions takes place when the ions travel close to the atomic plane from the observed relation between the charge state and the exit angle of the emerged ions. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nimb.2006.11.115

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMERICAN PHYSICAL SOC  

We have observed resonant coherent excitation (RCE) of H-like Ar17+ ions traveling through a 1 mu m-thick Si crystal at an energy of 391 MeV/u in the nonchanneling condition. A three-dimensional periodic array of atomic planes induces RCE of the nonchanneling ions. The high energy heavy ions together with the thin crystal allow us to observe this new RCE through the measurements of the charge-state distribution of the emerging ions. The observed resonances are much narrower than those of planar-channeling ions due to the absence of the large Stark shift caused by the planar potential.

DOI： 10.1103/PhysRevLett.97.135503

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記述言語：日本語   出版者・発行元：一般社団法人日本物理学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本物理学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本物理学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本物理学会  

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記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

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記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

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