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[en] We have described the x-ray optics and beamline performance of the ANL X6B beam line at the NSLS. Considerable flexibility has been built into the beam line to accommodate a wide range of x-ray diffraction, scattering, and spectroscopy experiments with various requirements. We presented selected examples of experimental results and showed that with the high intensity, high energy resolution, high-q resolution, and energy tunability, the X6B beam line has become a versatile facility
[en] We present a systematic study on the formation of ultra-slow bright and dark optical solitons in highly resonant media. By investigating four life-time broadened atomic systems, i.e., three-state Λ-type and cascade-type schemes, and four-state N-type and cascade-type schemes, we show that the formation of such ultra-slow solitons in cold atomic systems is a fairly universal phenomenon.
[en] Beam crossing schemes in the LHC interaction regions impose non-zero vertical closed orbit in the low-β triplets, which excite a perturbative periodic dispersion; the phenomenon is described and quantified in detail. It is shown that this dispersion reaches values at the limit of tolerances in the nominal optics of Version 5.0 of the LHC ring, and prohibitively large values in particular in the low- β quadrupoles and interaction regions in the foreseen extreme β-squeeze case (β* = 0.25 m). Such behaviour justifies including a local correction in the LHC design, in order to damp the effect and confine it as much as possible in the vicinity of the excitation sources (the low-β triplets). An optical compensation scheme based on the use of skew quadrupoles is described in detail, as well as the entailed residual dispersion
[en] High-current beams must be matched to high order to minimize emittance growth and particle losses. For matching problems, the moment approach, in which the author describes the particle beam by the moments of its distributions, is particularly valuable. A variety of analytical results are available for linear motion. The moment approach is also the basis of the 3-D space-charge simulation code BEDLAM, in which the dynamical variables are the moments. Moment simulation codes are particularly useful for computing beams matched to nonlinear systems. This paper outlines what is known about the moment approach, describes work in progress on new space-charge models, and describes further potential applications of and improvements to moment-method simulations
[en] In synchrotron-radiation (SR) beam lines, a beam viewer is needed for beam alignment after every optical element. A beam viewer comprising of a novel electromagnetically operated flipping mechanism has been designed and developed for operation in the ultra-high vacuum (uhv) environment. This flipping mechanism rotates a fluorescent screen by 45o to bring it into the path of the synchrotron beam. The beam position is then monitored using a CCD TV camera placed at 90o to the SR beam path. (author)