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Journal Articles

Optical diagnostics

Kawano, Yasunori

Denki Gakkai Gijutsu Hokoku, Dai-1018-Go, p.25 - 29, 2005/05

Aims of "The Investigation Committee on Pulsed Power Generation and Application" are to investigate recent developments on generation and control of pulsed power, to clarify the technological issues, and to provide the future prospects of such research area. This paper is written as the "section 3.3 Optical Diagnostics" in the technical report of the committee. Here, "diagnostics of relativistic electron beam in a torus plasma by laser inverse Compton scattering" is reported. This method has been newly proposed by JAERI for active measurement of the energy distribution of runaway electrons in a tokamak plasma. The paper presents the basic properties of scattered photons estimated in the case of runaway electron beam observed in JT-60U (number of beam electrons=2e17 electrons, beam electron energy = 30 MeV). For instance, when we use the fundamental YAG laser with the energy of 10 J/pulse and pulse widths of 1 ns, maximum energy of scattered photons would be in the X-ray region, and the signal to noise ratio can be estimated as 3. It is also mentioned that the development of the pulse X-ray imaging spectroscopy is required for this diagnostics method.

Journal Articles

Analysis of surface chemical reaction dynamics by using high brilliance and high energy-resolution synchrotron radiation

Teraoka, Yuden

Denki Gakkai Gijutsu Hokoku, (970), p.10 - 15, 2004/07

Si(001) surfaces are oxidized by O $_{2}$ molecules. The reaction schemes (oxide-layers formation, SiO desorption, their coexistence) are changed depending on the surface temperature and the gas pressure. The translational kinetic energy of incident O $_{2}$ molecules is recognizing to be an important parameter for controlling surface chemical reactions. The issues concerning translational kinetic energy induced oxidation by O $_{2}$ molecules at room temperature, effects of translational kinetic energy for SiO desorption processes at higher temperature than 1000 K, reaction mechanisms for coexistence of the SiO desorption and the oxide-layers formation in the temperature region from 900 K to 1000 K are reviewed.