Fast Switching Ferroelectric Materials for Accelerator Applications

Fast switching (< 10 nsec) measurement results on the recently developed BST(M) (barium strontium titanium oxide composition with magnesium-based additions) ferroelectric materials are presented. These materials can be used as the basis for new advanced technology components suitable for high-gradient accelerators. A ferroelectric ceramic has an electric field-dependent dielectric permittivity that can be altered by applying a bias voltage. Ferroelectric materials offer significant benefits for linear collider applications, in particular, for switching and control elements where a very short response time of <10 nsec is required. The measurement results presented here show that the new BST(M) ceramic exhibits a high tunability factor: a bias field of 40-50 kV/cm reduces the permittivity by a factor of 1.3-1.5. The recently developed technology of gold biasing contact deposition on large diameter (110 cm) thin wall ferroelectric rings allowed ~few nsec switching times in witness sample experiments. The ferroelectric rings can be used at high pulsed power (tens of megawatts) for X-band components as well as at high average power in the range of a few kilowatts for the L-band phase-shifter, under development for optimization of the ILC rf coupling. Accelerator applications include fast active X-band and Ka-band high-power ferroelectric switches, high-power X-band and L-band phase shifters, and tunable dielectric-loaded accelerating structures.Comment: 7 pages, 6 figures, submitted to Proceedings of 2006 Advanced Accelerator Concepts Worksho

Influence of Filler Metals in Welding Wires on the Phase and Chemical Composition of Weld Metal

The influence of filler metals used in welding wires on the phase and chemical composition of the metal, which is surfaced to mining equipment exposed to abrasive wear, has been investigated. Under a laboratory environment, samples of Mo-V-B and Cr-Mn-Mo-V wires were made. The performed experiments have revealed that fillers of the Cr-Mn-Mo-V system used in powder wire show better wear resistance of the weld metal than that of the Mn-Mo-V-B system; the absence of boron, which promotes grain refinement in the Mn-Mo-V-B system, significantly reduces wear resistance; the Mn-Mo-V-B weld metal has a finer structure than the Cr-Mn-Mo-V weld metal

Towards ultrametric theory of turbulence

Relation of ultrametric analysis, wavelet theory and cascade models of turbulence is discussed. We construct the explicit solutions for the nonlinear ultrametric integral equation with quadratic nonlinearity. These solutions are built by means of the recurrent hierarchical procedure which is analogous to the procedure used for the cascade models of turbulence.Comment: 11 page

Coherent population trapping in the stochastic limit

A 2-level atom with degenerate ground state interacting with a quantum field is investigated. We show, that the field drives the state of the atom to a stationary state, which is non-unique, but depends on the initial state of the system through some conserved quantities. This non-uniqueness follows from the degeneracy of the ground state of the atom, and when the ground subspace is two-dimensional, the family of stationary states will depend on a one-dimensional parameter. Only one of the stationary states in this family is a pure state, and this state coincides with the known non-coupled population trapped state (zero population in the excited level. Another one stationary state corresponds to an equal weight mixture of the excited level and of the coupled state.Comment: 13 pages, LaTe

Production of Welding Fluxes Using Waste Slag Formed in Silicomanganese Smelting

The possibility in principle of using slag, which is formed in the silicon-manganese smelting process, in producing welding fluxes is shown. The composition of and technology used for a new fused flux has been designed. A comparative evaluation of the new flux and the widely used AN-348 type flux was done. It has been proved that the new flux has high strength properties

On Quality of a Weld Bead Using Power Wire 35v9h3sf

The effect of introducing carbon-fluorine containing additives and nickel to flux-cored wire 35V9H3SF on its structure, micro hardness of martensite, hardness and wear rate of a welded layer has been investigated. It has been proven that carbon-fluorine additions to a powder mixture increase the hardness of the deposited layer and its wearing strength. Nickel adding increases the hardness of both martensite and the deposited layer, and reduces abrasion wear. Introducing carbon-fluorine containing additives to the powder mixture can reduce the pore formation and lower the level of impurity with nonmetallic inclusions; and nickel adding can lead to austenite having a finer grain size