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[en] This paper reports on an approach to investigate the dynamics of halo particles in mismatched charged-particle beams propagating through periodic-focusing channels using the particle-core model. The proposed method employs canonical transformations to minimize, in new phase-space variables, the flutter due to the periodic focusing to allow making stroboscopic plots. Applying this method, we find that in periodic-focusing systems, certain particles initially not in the halo region can be brought into resonance with the core oscillation to become halo particles. (c) 2000 The American Physical Society
[en] These lectures present a survey of some of the concepts of plasma physics and look at some situations familiar to particle-accelerator physicists from the point of view of a plasma physicist, with the intention of helping to link together the two fields. At the outset, basic plasma concepts are presented, including definitions of a plasma, characteristic parameters, magnetic pressure and confinement. This is followed by a brief discussion on plasma kinetic theory, non-equilibrium plasma, and the temperature of moving plasmas. Examples deal with beams in the CERN Intersecting Storage Rings as well as with non-steady beams in cyclic accelerators and microwave tubes. In the final chapters, time-varying systems are considered: waves in free space and the effect of cylinder bounds, wave motion in cold stationary plasmas, and waves in plasmas with well-defined streams. The treatment throughout is informal, with emphasis on the essential physical properties of continuous beams in accelerators and storage rings in relation to the corresponding problems in plasma physics and microwave tubes. (Author)
[en] In order to compress to high density, ignite and burn nuclear fusion fuel, the high power energy drivers which can give the energy of high intensity to targets are required. In this paper, the types of energy drivers developed in the main research institutes in the world, the relation between high power lasers and optical technology, and the present status of the development of new type, high performance energy drivers are described. The example of calculating the pellet gain obtained when high power laser beam or ion beam is irradiated on a target is shown. In order to limit the power required for operating an energy driver and others within 10 % of nuclear fusion output, the overall efficiency of the energy driver must be more than 5 %. Short wavelength, high power laser system is suitable to the direct or indirect irradiation of a target. Especially, the progress of the recent research on electron beam-excited KrF laser is remarkable. Particle beam is characterized by high efficiency and low cost, and PBFA-2 of 4 MJ is under construction. Glass lasers, gas lasers and particle beam apparatuses in the world are reviewed. The high accuracy automatic alignment of laser beam, high efficiency wavelength conversion and so on are explained. (Kako, I.)
[en] A new type of rf structure for the deflection and crabbing of particle beams is presented. The structure is comprised of a number of parallel TEM-resonant lines operating in opposing phase from each other. One of its advantages is its compactness compared to conventional crabbing cavities operating in the TM110 mode, thus allowing low frequency designs. The properties and characteristics of this type of structure are presented.
[en] BackgroundIn the light of scarce resources to be allocated for cancer care and a steady stream of costly innovations in all modalities applied to treat cancer, particle therapy needs to demonstrate its cost-utility balance to allow its positioning in the context of competing modalities. In the continuous evolving particle therapy landscape, the timely availability of appropriate economic data is crucial.
[en] A stability analysis of periodically focused intense particle beams based on the beam envelope equation is performed. We show that (i) the scenario, as the focusing field increases, is not the existence of a single threshold above which stable matched (equilibrium) solutions are absent, as generally believed, but the existence of successive regions of stability interrupted by gaps of instability; (ii) the beam can be focused to tighter radii using new stable matched solutions found for focusing field strengths greater than the previous threshold. Self-consistent simulations validate the findings