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Expressions are obtained for the instantaneous spectral and angular distribution of the radiation power and the angular distribution of the radiation energy of the two principal polarization components, and these expressions include the variations in the trajectory of a charged particle due to radiative damping. 相似文献
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B. Li I. Twesten N. Schwentner 《Applied Physics A: Materials Science & Processing》1993,57(5):457-467
The quality and efficiency of etching at room temperature is determined in the wavelength range from 105 nm to 300 nm by replicating a mask on a GaAs(100) wafer and by wavelength selection of synchrotron radiation with filters and a monochromator. A good anisotropy and selectivity is found for Cl2 pressures from 10–2 mbar up to 1.5 mbar, but above 3 mbar the selectivity is lost. Efficiencies for stimulation of the chlorination reaction and for desorption are separated and an optimal efficiency for stimulation of about 100 removed Ga and As atoms per photon is obtained around a wavelength of 122 nm at 1.5 mbar. Growth of reaction products on the surface occurs for short wavelengths and transport processes through layers up to a thickness of 350 nm are relevant. The efficiency and quality of etching can be improved by additional desorption with long wavelengths especially with lasers. 相似文献
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The stimulation of the endothermic beta decay of stable nuclei by the field of synchrotron radiation has been analyzed theoretically in the framework of the photobeta decay mechanism. In contrast to works devoted to the effect of laser fields on beta decay, the action of the field directly on a nucleus rather than on a beta electron is considered (a sufficiently intense flux of hard photons whose energies exceed 60 keV allows this action). The rates of such a beta decay are calculated for a number of “parent nucleus-daughter nucleus” pairs for the relativistic case including Coulomb effects. For the most intense available sources of synchrotron radiation, the rate of stimulated beta decay for most nuclei under investigation appears to be characteristic of third-forbidden β? transitions. The effect of synchrotron radiation on highly forbidden natural nuclear β? decays is also analyzed. In particular, irradiation increases the rate of the β? decay of the 37 87 Rb and 49 115 In nuclei by 2% and by almost two orders of magnitude, respectively. 相似文献
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The coherent synchrotron radiation (CSR) effect in a bending path plays an important role in transverse emittance dilution in high-brightness light sources and linear colliders, where the electron beams are of short bunch length and high peak current. Suppression of the emittance growth induced by CSR is critical to preserve the beam quality and help improve the machine performance. It has been shown that the CSR effect in a double-bend achromat (DBA) can be analyzed with the two-dimensional point-kick analysis method. In this paper, this method is applied to analyze the CSR effect in a triple-bend achromat (TBA) with symmetric layout, which is commonly used in the optics designs of energy recovery linacs (ERLs). A condition of cancelling the CSR linear effect in such a TBA is obtained, and is verified through numerical simulations. It is demonstrated that emittance preservation can be achieved with this condition, and to a large extent, has a high tolerance to the fluctuation of the initial transverse phase space distribution of the beam. 相似文献
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The spatial and spectral characteristics of laser-field synchrotron radiation (LSR) are investigated. The results show that LSR is emitted normal to the laser axis and emission in the X-ray wavelength can be obtained by increasing the intensity of the laser pulse and the initial energy of the electron. The unique feature offered by the laser-field synchrotron radiation (LSR) makes them a promising compact source of light at shorter wavelengths. 相似文献
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V.S. Malyshevsky 《Physics letters. A》2008,372(12):2133-2136
Correlation effects in the Cherenkov radiation due to ions charge fluctuations in the matter are considered. Stochastic process of charge exchange leads to the washout of a radiation wave front and to the transformation of spectral-angular density. The effect is determined by a root-mean-square deviation of an ion charge. The additional radiation yield gives the nonzero contribution at the violation of the Cherenkov threshold condition. The interference of an electromagnetic field generated in the matter by the different ion's charge states along the trajectory is the cause of the additional radiation. 相似文献
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Takao Nanba Yasuhito Urashima Mikihiko Ikezawa Makoto Watanabe Eiken Nakamura Kazutoshi Fukui Hiroo Inokuchi 《International Journal of Infrared and Millimeter Waves》1986,7(11):1769-1776
At the UVSOR Facility, Institute for Molecular Science, the practical use of the synchrotron radiation as a far-infrared light source has started. A spectroscopic system has been constructed at the beam line BL6A1 of UVSOR storage ring, which covers the wavenumber region from 5 to 250 cm–1. The cross sectional diameter of the light beam at the sample position is as small as 3 mm with the angular divergence of about 100 mrad. The system has been made mainly for the transmission and reflection measurements of small samples with small angular divergence by the use of the high brightness of the synchrotron radiation. Examples of observed transmission and reflectivity spectra are shown. 相似文献
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V. I. Sokolov V. A. Pustovarov N. B. Gruzdev P. S. Sokolov A. N. Baranov 《Optics and Spectroscopy》2014,116(5):790-792
We report the first observation of low-temperature luminescence of CoO crystals under synchrotron irradiation. At 8 K, the photoluminescence of CoO is characterized by smaller bandwidth and higher intensity relative to the corresponding photoluminescence band of NiO. The photoluminescence excitation spectra of CoO and NiO are similar. Position of the band related to charge transfer from oxygen ions to 3d-shell of cobalt ions is determined. The excitation energy is found to be 3.5 eV. 相似文献
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James E. Penner-hahn 《Synchrotron Radiation News》2013,26(5):2-3
The speakers at the main session of the 2005 National Synchrotron Light Source (NSLS) Annual Users' Meeting, held on Tuesday, May 24, at Brookhaven National Laboratory (BNL), spoke on many different topics. But they all conveyed excitement for the science performed at the NSLS, and expressed enthusiasm for its proposed successor, the world-leading NSLS-II. The incoming NSLS Users' Executive Committee Chair, Peter Stephens, welcomed the audience to the main meeting, setting a positive and enthusiastic tone for the day's events. He then opened the stage to BNL Director Praveen Chaudhari. Chaudhari commended many attendees for their work to advance NSLS-II. 相似文献