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Journal Articles

Quantum optimal control of the isotope-selective rovibrational excitation of diatomic molecules

Kurosaki, Yuzuru*; Yokoyama, Keiichi

Chemical Physics, 493, p.183 - 193, 2017/08


 Times Cited Count:3 Percentile:77.34(Chemistry, Physical)

Electric field of laser pulses which gives maximum selectivity in the isotope-selective rovibrational excitation of lithium chloride molecules is calculated. Applying the optimal control theory, we calculate optimal electric field to produce mixture of LiCl-35 ($$nu$$=0, $$J$$=0) and LiCl-37 ($$nu$$=1, $$J$$=1) from molecular ensemble of LiCl-35 ($$nu$$=0, $$J$$=0) and LiCl-37 ($$nu$$=0, $$J$$=0). As a result, it is found that electric field which permit rotational excitations only gives high yield in the selective excitation compared to the electric field which permit both rotational and vibrational excitations.

Journal Articles

Evaluation of annealing and double ion beam irradiation by a laser-induced and laser-detected surface acoustic wave diagnostic system

Kitazawa, Sin-iti*; Wakai, Eiichi; Aoto, Kazumi

Radiation Physics and Chemistry, 127, p.264 - 268, 2016/10

 Times Cited Count:2 Percentile:83.64(Chemistry, Physical)

The effects of annealing and double ion irradiation on nuclear structural materials were investigated using a novel, non-destructive, non-contact diagnostic method. A laser-induced and laser-detected surface acoustic wave (SAW) was adopted as a diagnostic system. The SAWs propagation velocity and the SAWs vibration velocity along the normal direction of the surface were measured to investigate mechanical properties of the substrates. Change of the shear modulus was detected in the annealed substrates. Non-linear effect on amplitude of the excited SAW was observed on the double ion irradiated materials. The potential of the SAW diagnostic system for assessing nuclear structural materials was demonstrated.

Journal Articles

Isotope-selective dissociation of diatomic molecules by terahertz optical pulses

Ichihara, Akira; Matsuoka, Leo*; Segawa, Etsuo*; Yokoyama, Keiichi

Physical Review A, 91(4), p.043404_1 - 043404_7, 2015/04

 Times Cited Count:10 Percentile:38.8(Optics)

We propose a new method for isotope-selective dissociation of diatomic molecules in the gas phase by using two kinds of terahertz-pulse fields. The first field consists of a train of pulses, which composes a frequency comb, excites the selected isotope into highly-rotationally excited state. The second intense pulse field dissociates the excited molecule by further rotational excitations. We performed wave-packet computations using the lithium chlorides $$^{7}$$Li$$^{35}$$CL and $$^{7}$$Li$$^{37}$$Cl to demonstrate the applicability of our method. Nearly 20% of $$^{7}$$Li$$^{37}$$Cl in the lowest rovibrational state is dissociated in the designed pulse fields, while the dissociation probability is negligible in $$^{7}$$Li$$^{35}$$Cl. This method is expected to be applicable to other diatomic molecules, and to molecular ensembles whose rotational states spread in energy.

Journal Articles

Analytic cross sections for electron impact collisions with nitrogen molecules

Tabata, Tatsuo*; Shirai, Toshizo*; Sataka, Masao; Kubo, Hirotaka

Atomic Data and Nuclear Data Tables, 92(3), p.375 - 406, 2006/05

 Times Cited Count:60 Percentile:5.97(Physics, Atomic, Molecular & Chemical)

no abstracts in English

Journal Articles

Development and operation of the JAERI superconducting energy recovery linacs

Minehara, Eisuke

Nuclear Instruments and Methods in Physics Research A, 557(1), p.16 - 22, 2006/02

 Times Cited Count:8 Percentile:46.47(Instruments & Instrumentation)

The JAERI FEL facility at Tokai, Ibaraki, Japan has been well known one of the two existing and operating superconducting energy recovery linacs together with one more of JLAB (Jefferson national accelerator facility) FEL facility at Newport News, Virginia, U.S.A. We have independently and successfully developed one of the most advanced and newest accelerator technologies named "superconducting energy recovery linacs (ERLs)" and the application technologies using ERLs in future. We plan to report the current high power FEL upgrade program research, stress corrosion cracking prevention technology research, large current and high brightness photoelectron gun research of negative-electron affinity (NEA) photocathode and NEA electron-excitation cathode as the most important elemental technology in realizing many powerful ERLs.

Journal Articles

Mechanism of state-specific enhancement in photon-stimulated desorption as studied using a polarization-dependent technique

Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Wu, G.*; Kitajima, Yoshinori*

Surface Science, 593(1-3), p.310 - 317, 2005/11

 Times Cited Count:2 Percentile:87.48(Chemistry, Physical)

Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids have been investigated. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed chlorobenzene.

Journal Articles

Direct and indirect processes in photon-stimulated ion desorption from condensed formamide

Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Baba, Yuji; Imamura, Motoyasu*; Matsubayashi, Nobuyuki*; Shimada, Hiromichi*

Surface Science, 593(1-3), p.303 - 309, 2005/11

 Times Cited Count:5 Percentile:72.18(Chemistry, Physical)

no abstracts in English

Journal Articles

$$R$$-dependence of spin exchange interactions in $$R$$MnO$$_{3}$$ ($$R$$ = Rare-Earth Ions)

Kajimoto, Ryoichi; Mochizuki, Hidenori*; Yoshizawa, Hideki*; Shintani, Hiroshi*; Kimura, Tsuyoshi*; Tokura, Yoshinori*

Journal of the Physical Society of Japan, 74(9), p.2430 - 2433, 2005/09

 Times Cited Count:32 Percentile:20.92(Physics, Multidisciplinary)

Magnon excitations have been investigated for PrMnO$$_{3}$$ showing the $textit{A}$-type antiferromagnetic ordering and TbMnO$$_{3}$$ forming a long-period spin ordering by inelastic neutron scattering. Combined with a result of LaMnO$$_{3}$$ [K.~Hirota $textit{et al.}$], the systematic data revealed that the ferromagnetic exchange interaction between nearest-neighbor (NN) Mn sites within the $$ab$$ plane drastically decreases in $$R$$MnO$$_{3}$$ as the ionic radius of $$R$$ is reduced. In addition, finite next-nearest-neighbor (NNN) coupling is evident in TbMnO$$_{3}$$. In contrast, the exchange interaction along the $$c$$ axis shows much weaker $$R$$ dependence consistent with the Mn-O-Mn bond angle. These observations confirm a scenario that explains the evolution of spin structures in $$R$$MnO$$_{3}$$ in terms of the competition between the NN and NNN interactions [T.Kimura $textit{et al.}$].

Journal Articles

Local bonding states of ion-irradiated graphite characterized by photon-stimulated desorption (PSD) spectroscopy

Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.

Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.437 - 441, 2005/06

 Times Cited Count:3 Percentile:81.44(Spectroscopy)

no abstracts in English

Journal Articles

Characterization and degradation of ZEP520 resist film by TOF-PSID and NEXAFS

Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Koike, Masaki*

Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.453 - 455, 2005/06

 Times Cited Count:13 Percentile:46.72(Spectroscopy)

no abstracts in English

Journal Articles

Polarization-dependent dissociation selectively induced by core-electron excitation in methyl ester terminated self-assembled monolayer

Kizaki, Hiroyuki*; Wada, Shinichi*; Sako, Erika*; Sumii, Ryohei*; Waki, Satoshi*; Isari, Koji*; Sekitani, Tetsuji*; Sekiguchi, Tetsuhiro; Tanaka, Kenichiro*

Journal of Electron Spectroscopy and Related Phenomena, 144-147, p.447 - 451, 2005/06

 Times Cited Count:5 Percentile:70.85(Spectroscopy)

no abstracts in English

Journal Articles

The 5$$nu$$$$_{rm NH}$$ and 5$$nu$$$$_{rm ND}$$ vibrational bands of partially deuterated ammonia species

Akagi, Hiroshi; Yokoyama, Keiichi; Yokoyama, Atsushi; Wada, Akira

Journal of Molecular Spectroscopy, 231(1), p.37 - 49, 2005/05

 Times Cited Count:2 Percentile:87.43(Physics, Atomic, Molecular & Chemical)

Absorption spectra of gaseous samples containing NH$$_{2}$$D and NHD$$_{2}$$ have been measured in 11580-11880 and 15280-15610 cm$$^{-1}$$ regions, corresponding to the 5$$nu$$$$_{rm ND}$$ and 5$$nu$$$$_{rm NH}$$ vibrational bands, respectively. Photoacoustic spectroscopy has been utilized for the measurement. The molecular constants of NH$$_{2}$$D in the 5$$nu$$$$_{rm ND}$$ state and NHD$$_{2}$$ in the 5$$nu$$$$_{rm NH}$$ state have been determined by the analysis of the obtained absorption spectrum. Comparing the constants with those of the vibrational ground states, structural changes caused by the stretching excitations have been elucidated. The HND bond angles are decreased by these excitations. The dependence of the molecular constants on the stretching quantum number has been also derived by simple Birge-Sponer and Dunham analyses.

Journal Articles

High-energy resolution inelastic neutron scattering experiment on magnetic fracton dispersion in near-percolating three-dimensional Heisenberg antiferromagnet, RbMn$$_{0,4}$$Mg$$_{0.6}$$F$$_{3}$$

Ito, Shinichi*; Kajimoto, Ryoichi; Adams, M. A.*

Journal of the Physical Society of Japan, 74(1), p.279 - 282, 2005/01

 Times Cited Count:3 Percentile:72.02(Physics, Multidisciplinary)

Magnetic fractons in the near-percolating three-dimensional (3D) Heisenberg antiferromagnet, RbMn$$_{0.4}$$Mg$$_{0.6}$$F$$_{3}$$, have been studied using inelastic neutron scattering with high energy resolution ($$Delta E=17.5 mu$$eV) and at low temperature ($$T=1.5$$ K). It is demonstrated that the fractons follow the dispersion relation of $$q^z$$ (q being the wave number). The observed exponent, $$z=2.5$$, is in good agreement with the fractal dimension of the 3D system ($$D_f=2.48$$), as predicted by theory.

Journal Articles

Optimal control of ultrafast selection

Yokoyama, Keiichi; Teranishi, Yoshiaki; Toya, Yukio; Shirai, Toshizo; Fukuda, Yuji; Aoyama, Makoto; Akahane, Yutaka; Inoue, Norihiro*; Ueda, Hideki; Yamakawa, Koichi; et al.

Journal of Chemical Physics, 120(20), p.9446 - 9449, 2004/05

 Times Cited Count:5 Percentile:83.4(Chemistry, Physical)

Optimal laser control for ultrafast selection of closely-lying excited states, whose energy separation is smaller than the laser bandwidth, is reported on the two-photon transition of atomic cesium; Cs(6S $$rightarrow$$ 7D$$_{J}$$, J = 5/2 and 3/2). Selective excitation was carried out by pulse shaping of ultrashort laser pulses which were adaptively modulated in a closed-loop learning system handling eight parameters representing the electric field. Two-color fluorescence from the respective excited states was monitored to measure the selectivity. The fitness used in the learning algorithm was evaluated from the ratio of the fluorescence yield. After fifty generations, a pair of nearly transform-limitted pulses were obtained as an optimal pulse shape, proving the effectiveness of "Ramsey fringes" mechanism. The contrast of the selection ratio was improved by $$sim$$ 30 % from the simple "Ramsey fringes" experiment.

Journal Articles

Multiple coulomb excitation experiment of $$^{68}$$Zn

Koizumi, Mitsuo; Seki, Akiyuki*; Toh, Yosuke; Osa, Akihiko; Utsuno, Yutaka; Kimura, Atsushi; Oshima, Masumi; Hayakawa, Takehito; Hatsukawa, Yuichi; Katakura, Junichi; et al.

Nuclear Physics A, 730(1-2), p.46 - 58, 2004/01

 Times Cited Count:13 Percentile:36.56(Physics, Nuclear)

Coulomb excitation experiment was carried out with a $$^{68}$$Zn beam bombarding a $$^{nat}$$Pb target. Two $$E2$$ matrix elements and the quadrupole moment of the 2$$_{1}$$$$^{+}$$ state were newly derived with the least-squares search code GOSIA. The potential energy surface (PES) was calculated with the Nilsson-Strutinsky model, showing two shallow minima: the first minimum does not contain the $$1g_{9/2}$$ orbit below the Fermi surface, while the second minimum does. The ground state band and the intruder band seem to be constructed on the first and the second minimum, respectively. As for the ground state band, the asymmetric rotor model and the IBM in O(6) limit reproduced the experimental values rather well. The shallow PES may suggest unstability of the shape. The ground state band structure may be explained assuming a soft triaxial deformation.

Journal Articles

Fragmentation pathways caused by soft X-ray irradiation; The detection of desorption products using a rotatable time-of-flight mass-spectrometer combined with pulsed synchrotron radiation

Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.

Free Electron lasers 2003, p.II_69 - II_70, 2004/00

no abstracts in English

Journal Articles

New applications of ion beams to material, space, and biological science and engineering

Fukuda, Mitsuhiro; Ito, Hisayoshi; Oshima, Takeshi; Saido, Masahiro; Tanaka, Atsushi

Charged Particle and Photon Interactions with Matter, p.813 - 859, 2003/11

An ion beam has been widely applied to a variety of research fields of materials, space, and bio-sciences. Notable results, which were hard to obtain in applications of a $$gamma$$ ray and an electron beam, have been produced by the ion beam application. Ion beams interacting with matter have such superior properties as highly localized ionization and excitation, production of secondary particles, implantation of different atoms, and nuclear transmutation of constituent atoms. Skillful utilization of the ion beam properties makes remarkable progress in creation of new materials and precise investigation of matters. The ion beam irradiation research facility, TIARA, was established in 1993 at JAERI for extensive applications of ion beams. An accelerator complex provides light to heavy ion beams with a broad energy range from keV to GeV. Various ion beam technologies pioneering the ion beam applications have been developed at TIARA. In this paper, new applications of accelerated ion beams to material, space, and biological science and engineering carried out mainly at TIARA are reviewed.

Journal Articles

Element- and orientation-selective photo-fragmentation using polarized synchrotron radiation

Sekiguchi, Tetsuhiro; Ikeura-Sekiguchi, Hiromi*; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.

Photon Factory Activity Report 2002, Part B, P. 80, 2003/11

no abstracts in English

Journal Articles

Multiple Coulomb Excitation Experiment of $$^{66}$$Zn

Koizumi, Mitsuo; Seki, Akiyuki*; Toh, Yosuke; Oshima, Masumi; Osa, Akihiko; Kimura, Atsushi; Hatsukawa, Yuichi; Shizuma, Toshiyuki; Hayakawa, Takehito; Matsuda, Makoto; et al.

European Physical Journal A, 18(1), p.87 - 92, 2003/10

 Times Cited Count:13 Percentile:35.14(Physics, Nuclear)

no abstracts in English

Journal Articles

The Resonance Raman effect of uranyl formate in dimethyl sulfoxide

Soga, Takeshi

Spectrochimica Acta, Part A, 59(11), p.2497 - 2510, 2003/09

no abstracts in English

110 (Records 1-20 displayed on this page)