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Tsubouchi, Masaaki; Ochi, Yoshihiro; Tanaka, Momoko; Yoshida, Fumiko; Nagashima, Keisuke
no journal, ,
We are developing intense THz light source to realize control of molecular axis orientation in space. From the theoretical studies by Hebling and co-workers, it has been known that the desirable excitation NIR pulse for the THz light generation process in the Mg-sLiNbO
crystal should have the pulse width of 400 fs 
1 ps, and the tilted pulse front by 63 degree. To generate such NIR light, the Yb:YAG based amplifier system is one of the good candidates. By using this system, we are trying to generate the intense THz light with the high repetition rate (1 kHz).
Harries, J.; Crespo L
pez-Urrutia, J.*
no journal, ,
Inoue, Naoki*; Nagoshi, Tatsuro*; Yoda, Yumi*; Suzuki, Norihiro*; Harries, J.; Koike, Fumihiro*; Azuma, Yoshiro*
no journal, ,
Nakano, Motoyoshi; Otobe, Tomohito; Itakura, Ryuji
no journal, ,
no abstracts in English
adsorption on Ni(001) surface at room temperatureIwai, Yutaro*; Teraoka, Yuden; Okada, Ryuta; Yoshigoe, Akitaka
no journal, ,
Au(111) oxidationTsuda, Yasutaka*; Makino, Takamasa*; Hashinokuchi, Michihiro*; Okada, Michio*; Oka, Kohei*; Di
o, W. A.*; Kasai, Hideaki*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Akagi, Hiroshi; Kasajima, Tatsuya*; Kumada, Takayuki; Itakura, Ryuji; Yokoyama, Atsushi; Hasegawa, Hirokazu*; Oshima, Yasuhiro*
no journal, ,
We are demostrating isotope-selective ionization of 
N and 
N isotopologues, utilizing molecular alignment and angular dependent ionization. In the present work, we used a train of four identical pulses with 125.7-ps interval to creating rotational wave packets in these isotopologues. We optimized the following experimental conditions to improve the isotope selectivity: mixing ratio of the gas sample, timing of pulse valve to introduce the gas sample into a vacuum chamber, laser beam diameters for the alignment and ionization pulses, and these peak intensities. As the results, we obtained the minimum of the ion yield ratio N/N (= 0.49) and the maximum (= 2.00).
O/
O isotope separation by infrared multiphoton dissociation of 2,3-dihydropyranYokoyama, Atsushi
no journal, ,
We have examined previously the mechanism for the increase of the enrichment factor of O with the increase of sample pressure in the isotope separation of O/O by the infrared multiphoton dissociation of 2,3-dihydropyran. In this time, in order to examine the validity of the parameters used in the rate-equation model, we estimated the average vibrational energy during the infrared multiphoton dissociation process by a time-resolved Raman spectroscopy. The energy is in good agreement with that calculated by using the rate-equation model, and the parameters in the model was found to be reasonable. In this symposium, we will also discuss the mechanism for the increase of the enrichment factor on the basis of the enrichment factor calculated with the model.
CsI + CsKobayashi, Takanori; Hashimoto, Masashi; Yokoyama, Keiichi
no journal, ,
To investigate the possibility of the Cs exchange reaction, we have analyzed the Cs-I-Cs triatomic molecule by using quantum chemistry calculation. Furthermore, by using the newly developed capture model, the Cs exchange reaction rate and its temperature dependence were estimated. 2-dimensional potential energy surface around CsI against Cs atom shows that the reaction has no entrance barrier. The reaction rate was found to be close to the collision rate and to have a little temperature dependence would be expected.
Fukahori, Shinichi*; Nakano, Motoyoshi; Yamanouchi, Kaoru*; Itakura, Ryuji
no journal, ,
Dissociative ionization of methanol is investigated. We confirm the presence of the two types of ionization and electronic excitation pathways based on the channel-specific photoelectron spectra and the energy correlation between the photoelectron and the fragment recoil. Furthermore, from the three dimensional momenta of the photoelectron and the CH
fragment ion detected in coincidence, energy-resolved molecular-frame photoelectron angular distributions are obtained.
Itakura, Ryuji; Fushitani, Mizuho*; Hishikawa, Akiyoshi*; Sako, Tokuei*
no journal, ,
We theoretically investigate how such an effect appears in ultrafast ionization, by explicitly treating the correlation between a photoelectron and a photoion. One-photon ionization of Ar by a linearly polarized EUV pulse is considered as a model case. The mechanism governing the coherence in the ion will be revealed by examining the temporal variation in the hole density of Ar
in a photoelectron-energy resolved manner.
Shimada, Hiroyuki*; Minami, Hirotake*; Sakuma, Ichiro*; Okuizumi, Naoto*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
no journal, ,
Hashimoto, Masashi; Matsuoka, Leo*; Kurosaki, Yuzuru; Yokoyama, Keiichi
no journal, ,
We obtained the updated results of the dissociation energy of potassium chloride molecule as a result of the photofragment momentum-imaging spectroscopy of the KCl. The observed momentum images were processed by an inverse Abel transform with polar basis set expansion method to extract the slice image and then to obtain the ion kinetic energy and angular distributions. Internal energy distribution of KCl molecule was obtained based on the radial distribution of K
along the perpendicular direction. These signals were resolved into the thinner rings, arising from the vibrational hot bands of KCl. The radii of velocity distribution peaks shrink with decreasing laser photon energy. The dissociation energy of KCl was determined to be 100.8 
0.1 kcal/mol from laser photon energy dependence of the peak position for v = 0 and was found to be consistent with the literature value 102.6 2.0 kcal/mol.
) in the bulk gas phaseYokoyama, Keiichi; Yoshida, Fumiko
no journal, ,
Isotope-selective heating, the principle of our new cesium isotope separation scheme, was demonstrated by the stimulated Raman scattering with near infrared femtosecond laser pulses. At the room temperature and 200 Torr of gas pressure, the bulk nitrogen gas was excited with focused Ti:S laser pulses, which was shaped to eight-pulse train from a single 50 fs, 800 nm pulse. The field strength reached 3
10
W/cm
. The pulse interval was set to be 8.4 ps, the classical rotation period of N. The rotational state distribution was measured by the coherent anti-Stokes Raman scattering spectroscopy. Comparing the results between N and N, we can conclude that large displacement of rotational distribution occurs for N but not for N.