Sears博士講演会の案内

このたび、米国ブルックヘブン国立研究所/ニューヨーク州立大学ストーニーブルック校のTrevor J. Sears博士が来日しますので、 京都でのミニシンポジウムと東京でのセミナーをお願いすることになりました、。多数の皆様のご来聴をお待ちしております。

なお、博士の講演は東京・京都で同じものをお願いしております。

講演要旨

New laser-based spectroscopic techniques permit one to address long- standing problems involving collisional processes in gases with unprecidented precision and accuracy. This talk covers some recent work on the measurement of state-to-state processes in methylene (CH2) and cyanogen (CN) radicals by high resolution laser absorption spectroscopy in the near infrared. A complementary, more global, view of the consequences of collisions is available from precision line shape measurements and some have been completed for both CN and C2H2 and new frequency comb referenced measurements will also be described.

In CH2, collisional intersystem crossing (CISC) between the low- lying singlet excited electronic state and the ground, less chemcially reactive, triplet state is mediated by a few rotational levels that possess mixed electronic state character as a result of their similar energies and the weak spin-orbit coupling in the radical. This picture of CISC in methylene is supported by studies of the rates of loss of population from the zero point level of the ~a 1A1 state, but new measurements of the v2 = 1 level seem to contradict the model predictions.

Collisional rotational energy transfer (RET) in CN collisions with He and Ar provide a model system that is more amenable to first principles calculations. Probing a single rotational, or even hyperne, level of the ground X state of CN, we have measured the RET rates for a number of levels for different collsion partners at a variety of pressures to compare to recent calculations. In addition, global line shape measurements have been made for CN and, in separate experiments, C2H2 and the results analyzed in terms of several speed-dependent line shape models. Signal-to-noise ratios of up to 10^5 have been achieved in some of the C2H2 measurements and these provide very stringent tests of line shape models and can be used to assess the validity of physical descriptions such as speed-dependent and Dicke narrowing effects.

Acknowledgments: Work at Brookhaven National Laboratory was carried o ut under Contract No. DE-AC02-98CH10886 with the U.S. Department of E nergy and supported by its Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences.

分子分光京都ミーティング 7月26日(土)@京都大学

時間:13-16:30

場所:京都大学理学セミナーハウス北部構内地図、建物番号9

プログラム

Keynote Lecture: Dr. Trevor J. Sears "SPECTROSCOPIC AND DYNAMICAL STUDIES OF SMALL FREE RADICALS AND MOLECULES"

Invited Lecture: 高須 洋介博士(京都大学)"Photoassociation of Ultracold Yb Atoms"

Several short talks on experiments and theoretical calculations

問い合わせ先:馬場正昭教授(京都大学)baba -at- kuchem.kyoto-u.ac.jp (-at-を@にしてください)

セミナー 7月30日(水)@東京大学本郷キャンパス

時間:15:00~16:00

場所:東京大学 理学部1号館414号室

問い合わせ先:小林かおり(富山大学)kaori -at- sci.u-toyama.ac.jp (-at-を@にしてください)

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