MONTE CARLO SIMULATIONS OF MUON PRODUCTION

Muon production requirements for a muon collider are presented. Production of muons from pion decay is studied. Lithium lenses and solenoids are considered for focussing pions from a target, and for matching the pions into a decay channel. Pion decay channels of alternating quadrupoles and long solenoids are compared. Monte Carlo simulations are presented for production of $\pi \rightarrow \mu$ by protons over a wide energy range, and criteria for choosing the best proton energy are discussed.Comment: Latex uses mu95.sty, 19 pages, 5 postscript figures. A postscript file can be seen at URL http://www.cap.bnl.gov/~cap/mumu/important.html Search for Publication

Recent Progress of RF Cavity Study at Mucool Test Area

In order to develop an RF cavity that is applicable for a muon beam cooling channel, a new facility, called Mucool Test Area (MTA) has been built at Fermilab. MTA is a unique facility whose purpose is to test RF cavities in various conditions. There are 201 and 805 MHz high power sources, a 4-Tesla solenoid magnet, a cryogenic system including a Helium liquifier, an explosion proof apparatus to operate gaseous/liquid Hydrogen, and a beam transport line to send an intense H- beam from the Fermilab Linac accelerator to the MTA hall. Recent activities at MTA will be discussed in this document.Comment: 4 pp. 13th International Workshop on Neutrino Factories, Superbeams and Beta beams (NuFact11) 1-6 Aug 2011: Geneva, Switzerlan

Dynamic Behavior of Droplet Impact on Inclined Surfaces with Acoustic Waves

Droplet impact on arbitrary inclined surfaces is of great interest for applications such as antifreezing, self-cleaning, and anti-infection. Research has been focused on texturing the surfaces to alter the contact time and rebouncing angle upon droplet impact. In this paper, using propagating surface acoustic waves (SAWs) along the inclined surfaces, we present a novel technique to modify and control key droplet impact parameters, such as impact regime, contact time, and rebouncing direction. A high-fidelity finite volume method was developed to explore the mechanisms of droplet impact on the inclined surfaces assisted by SAWs. Numerical results revealed that applying SAWs modifies the energy budget inside the liquid medium, leading to different impact behaviors. We then systematically investigated the effects of inclination angle, droplet impact velocity, SAW propagation direction, and applied SAW power on the impact dynamics and showed that by using SAWs, droplet impact on the nontextured hydrophobic and inclined surface is effectively changed from deposition to complete rebound. Moreover, the maximum contact time reduction up to ∼50% can be achieved, along with an alteration of droplet spreading and movement along the inclined surfaces. Finally, we showed that the rebouncing angle along the inclined surface could be adjusted within a wide range

Investigating femtosecond laser interaction with tellurite glass family

Focusing ultrafast laser pulses induce localized permanent structural modifications on the surface or in transparent materials, that are of particular interest for photonic applications. Among the materials of interest, the tellurite glass family is attractive for near-infrared and photonics applications due to its broad-transparency window and high optical nonlinearity. Here, we systematically investigate structural changes occurring in various TeO2-based glasses exposed to femtosecond laser with various laser parameters. Remarkably, in a regime where heat accumulated after successive pulses, we observed the formation of polarization-controlled self-organized patterns expanding well beyond the focal volume, suggesting the presence of an evanescent coupling mechanism enhancing the self-organization. In addition, our results, obtained with compositional elemental analysis coupled with Raman spectra suggest different ion migration mechanisms in the laser affected zone at the surface and inside the glass. The formation of crystalline tellurium (t-Te) from glass structural units due to photo-induced elemental dissociation was observed only at the surface. The formation of ultrathin layer of crystalline tellurium offers the possibility to explore structural transitions in two-dimensional (2D) glasses by observing changes in the short- and medium- range structural orders, induced by spatial confinement

Polysulfone/Clay Nanocomposites by in situ Photoinduced Crosslinking Polymerization

Cataloged from PDF version of article.PSU/MMT nanocomposites are prepared by dispersing MMT nanolayers in a PSU matrix via in situ photoinduced crosslinking polymerization. Intercalated methacrylate-functionalized MMT and polysulfone dimethacrylate macromonomer are synthesized independently by esterification. In situ photoinduced crosslinking of the intercalated monomer and the PSU macromonomer in the silicate layers leads to nanocomposites that are formed by individually dispersing inorganic silica nanolayers in the polymer matrix. The morphology of the nanocomposites is investigated by XRD and TEM, which suggests the random dispersion of silicate layers in the PSU matrix. TGA results confirm that the thermal stability and char yield of PSU/MMT nanocomposites increases with the increase of clay loading

A model of rf breakdown arcs

This paper presents a rst iteration of a model that attempts to describe all aspects of breakdown in rf cavities and provides some estimates of the parameters and parameter ranges involved, as an aid to producing more precise models and more useful experiments. The model describes how breakdown events can be triggered, how they grow, it identi es the power source for their rapid growth, mechanisms that limit their growth, how they are extinguished and how they can be mitigated. We also discuss applications to superconducting rf and high pressure gas structures. The model relies heavily on previous experiments with 805 and 201 MHz warm copper cavities, and pre-liminary plasma modeling using the code OOPIC Pro. We compare estimates from the model with experimental data where this is possible. Because of the geometrical dependence of all parameters, the wide range of experiments being performed, the wide range of experimental parameters in a given breakdown event and the lack of extensive systematic parameter searches at this stage in our studies, it is diffcult to present precise results. We are constrained to showing what mechanisms are involved, the strength of these mechanisms and how they interact to produce the experimental data. We are primarily interested in the development and dynamics of the arc, magnetic and gas effects and insights on how to avoid arcing in all environments

Kinetic and Equilibrium Studies of Adsorption of Reactive Red 120 on Chitin

Chitin is a natural compound that can be extracted from various organisms that is used in various applications from medicine to environmental applications. In this study, effect of chitin is followed for adsorption of reactive red 120 textile dye from water at different conditions such as pH, initial concentration of dye, ionic strength, initial concentration of chitin, effect of temperature, effect of contact time. Characterization of the adsorption were recorded by Fourier Transform Infrared FT-IR spectroscopy