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[en] This paper forms the introductory chapter to a book concerning the use of synchrotron radiation for investigation of the structure and mechanism of biological macromolecules. After a historical section, the physics of synchrotron radiation is summarized so that the most promising experiments may be extrapolated. Irradiated power and intensity, polarization and angular distribution, brilliance of a real source, and developments such as wigglers and undulators are briefly dealt with. The paper includes a tabulated compilation of proposed and operating machines in 1982, with some of their characteristics. (U.K.)

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[en] The emission of electromagnetic waves around the electron cyclotron frequency is strongly enhanced when double layers are formed in magnetized collisionless plasmas. The emission intensity is well correlated with an electron current passing through the double layers. (orig.)

[en] We have deduced the intensity spectral function for the spin-flip synchrotron radiation in the presence of a plasma. Using parameters appropriate to astrophysical conditions, we have attempted to compare the characteristics of the spin-flip synchrotron radiation and the normal synchrotron radiation in a magnetized plasma arising from the electron or positron rotating around the magnetic field. A rotating charge gives the maximum possible synchrotron radiative power as compared to a charge of the same energy but moving in a helical path. Since the spin-flip radiational does not depend on the form of the orbital path, whether circular or helical or along a straight line, the analysis presented here gives the lower limit of the relative importance of the spin-flip radiation to the normal synchrotron radiation emitted by the same radiator. (orig.)

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[en] A new analytical formulation of the synchrotron absorption and emission coefficient in plasmas, for wave propagation perpendicular to the magnetic field, has been derived previously [Phys. Fluids 29, 3275 (1986)]. These coefficients were shown to be both accurate and analytically simple. Their generalization to arbitrary directions of propagation with respect to the magnetic field is presented here. Based on the analytical formulas for perpendicular propagation and on the exact sum--integral formulation of the coefficients for arbitrary propagation, this generalization is achieved by empirical data fit. Hereby the exact formulation serves as target function for the fitting procedure and subsequently as reference for determination of the accuracy of the results. The generalized analytical representations for the coefficients are presented here, one for each polarization mode and for the low and high temperature domain (above and below a few tens of kilo-electron-volts)

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[en] The Long Trace Profiler (LTP) is a useful optical metrology instrument for measuring the figure and slope error of cylindrical aspheres commonly used as synchrotron radiation (SR) optics. It is used extensively at a number of synchrotron radiation laboratories around the world. In order to improve SR beam line quality and resolution, the National Synchrotron Radiation Laboratory (NSRL) of China is developing a versatile LTP that can be used to measure both SR optics and more conventional ''normal'' optical surfaces. The optical metrology laboratories at Brookhaven National Laboratory (BNL) and NSRL are collaborating in developing a multiple functions LTP (LTP-MF). Characteristics of the LTP-MF are: a very compact and lightweight optical head, a large angular test range (± 16 mad) and high accuracy. The LTP-MF can be used in various configurations: as a laboratory-based LTP, an in-situ LTP or penta-prism LTP, as an angle monitor, a portable LTP, and a small radius of curvature test instrument. The schematic design of the compact optical head and a new compact slide are introduced. Analysis of different measurements modes and systematic error correction methods are introduced