116200939
Self-Stimulated Undulator Radiation and its Possible Applications
We investigated the phenomena of self-stimulation of incoherent emission from an undulator installed in the linear accelerator or quasi-isochronous storage ring. We discuss possible applications of these phenomena for the beam physics also.
173184854
Proposal of a compact repetitive dichromatic x-ray generator with millisecond duty cycle for medical applications
Main practical applications of X-rays lie in the important for the society fields of medical imaging, custom, transport inspection and security. Scientific applications besides of fundamental research include material sciences, biomicroscopy, and protein crystallography. Two types of X-ray sources dominate now: conventional tubes and electron accelerators equipped with insertion devices. The first are relatively cheap, robust, and compact but have low brightness and poorly controlled photon spectrum. The second generate low divergent beams with orders of magnitude higher brightness and well-controlled and tunable spectrum, but are very expensive and large in scale. So accelerator based X-ray sources are mainly still used for scientific applications and X-ray tubes--in commercial equipment. The latter motivated by the importance for the society made an impressive progress during last decades mostly due to the fast developments of radiation detectors, computers and software used for image acquisition and processing. At the same time many important problems cannot be solved without radical improvement of the parameters of the X-ray beam that in commercial devices is still provided by conventional X-ray tubes. Therefore there is a quest now for a compact and relatively cheap source to generate X-ray beam with parameters and controllability approaching synchrotron radiation. Rapid developments of lasers and particle accelerators resulted in implementation of laser plasma X-ray sources and free electron lasers for various experiments requiring high intensity, shrt duration and monochromatic X-ray radiation. Further progress towards practical application is expected from the combination of laser and particle accelerator in a single unit for efficient X-ray generation.
13357439
Cherenkov glue in opaque nuclear medium
Abstract The spectrum of Cherenkov gluons is calculated within the framework of in-medium QCD. It is compared with experimental data on the double-humped structure around the away-side jet obtained in the experiments STAR and PHENIX at RHIC. The values of the real and imaginary parts of the permittivity of the medium created in ultrarelativistic nuclear collisions are obtained from these fits. It is shown that accounting for an additional smearing of transverse momenta of Cherenkov gluons in the medium allows to provide a very good description of the experimental data.
115322655
Single photon and neutral meson production in nuclear collisions at 200-A/GeV
126402897
On multiple generalizations of Lie algebras and Poisson manifolds
7992539
Vacuum Einstein metrics with bidimensional Killing leaves ∗ I-Local aspects.
Abstract The solutions of vacuum Einstein's field equations, for the class of Riemannian metrics admitting a non-Abelian bidimensional Lie algebra of Killing fields, are explicitly described. They are parametrized either by solutions of a transcendental equation (the tortoise equation ), or by solutions of a linear second order differential equation in two independent variables. Metrics, corresponding to solutions of the tortoise equation, are characterized as those that admit a 3-dimensional Lie algebra of Killing fields with bidimensional leaves.
117029742
Two-particle correlations of pions and light nuclear fragments in nucleus-nucleus interactions at an energy of 3.6 GeV/nucleon
ACorrelations between a charged particle emitted in the angular interval 10-32{degrees} (in the lab system) and a pion emitted in the angular interval 45-135{degrees} are measured for the interactions of {sup 12}C and {sup 4}He nuclei of energy 3.6 GeV/nucleon with various nuclear targets. In all cases, the correlated emission of such particles is discovered. As in the case of baryonic nuclear fragments, correlations are negative for light targets (a fragment and the first particle are emitted preferentially in opposite directions). However, in contrast to the case of baryonic fragments, the amplitudes of the correlations decrease with increasing mass of the target nucleus, and correlations even become positive in the case of a Pb target. The magnitudes of the correlations depend systematically on the characteristics of the entrance and exit channels. As in the case of baryonic nuclear fragments, these observations are consistent with the notion of collective motion in nuclear matter. In addition, the effect of pion rescattering with reflection in nuclear matter is observed. 6 refs., 3 figs.