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Kumada, Takayuki; Karavitis, M.*; Goldschleger, I. U.*; Apkarian, V. A.*
Hoshasen Kagaku, (79), p.30 - 35, 2005/03
We should know how the high energy deposited by irradiation dissipates in materials in order to understand radiation chemical processes. In this study, we carried out TR-CARS (Time-Resolved Coherent Anti-Stokes Raman Scattering) study of molecular iodine in solid krypton to understand the mechanism of vibrational relaxation in solid phase. Decoherence of the vibrational state is due to energy dissipation below 10 K whereas pure dephasing plays an important role above. We also found that the dephasing is due to the scattering with local phonon mode with the energy of 40 K.
(v = 1-19) in solid KrKaravitis, M.*; Kumada, Takayuki; Goldschleger, I. U.*; Apkarian, V. A.*
Physical Chemistry Chemical Physics, 7(5), p.791 - 796, 2005/02
Times Cited Count：30 Percentile：67.62(Chemistry, Physical)Energy dissipation and phase relaxation of the vibrational quantum states of iodine molecules in solid krypton have been studied in the temperature range between 7 and 45 K using a technique of time-resolved coherent anti-stokes Raman scattering (CARS) spectroscopy by a femto-second laser. The rate of energy dissipation was independent of tempeature, but proportional to the vibrational quantum number v. The pure dephasing rate exponentially increased with an increase in temperature and was proportional to v
. The energy relaxation was found to take place by transfering the vibrational energy of iodine to four phonons in the krypton solid. The pure dephasing was induced by elastic scattering with phonon. It was suggested by a computer simulation that the phonon which induced the pure dephasing accompanied libration mode of iodine molecules.
Gordon, E. B.*; Kumada, Takayuki; Ishiguro, Masazumi; Aratono, Yasuyuki
Journal of Experimental and Theoretical Physics, 99(4), p.776 - 783, 2004/10
The solid Deuterium clusters for the first time isolated in a matrix of solid Helium have been investigated at T = 1.3K and P = 3 MPa by CARS (Coherent anti-Stokes Raman spectroscopy) technique. The Q1(J=0) and Q1(J=1) lines intensity, shape and positions have been studied as the functions of ortho- para content in the solid, as well as of clusters size. The strong effect of Raman scattering cross section sensitivity to the molecular environment nuclear spin state has been found in CARS; the ratio of probabilities for the scattering by para (J=1) and ortho (J=0) deuterium being equal to 1 in a gas is as high as 10,000 in nearly pure o-D2, whereas it is about 50 in spontaneous Raman scattering. This effect has been shown to give rise starting from cluster size corresponding to the phonon band onset.
