BPM Button Optimization to Minimize Distortion Due to Trapped Mode Heating

Abstract The outer circumference of a BPM button and the inner circumference of the button housing comprise a transmission line. This transmission line typically presents an impedance of a few tens of ohms to the beam, and couples very weakly to the 50 ohm coaxial transmission line that comprises the signal path out of the button. The modes which are consequently excited and trapped often have quality factors of several hundred, permitting resonant excitation by the beam. The thermal distortion resulting from trapped mode heating is potentially problematic for achieving the high precision beam position measurements needed to provide the submicron beam position stability required by light source users. We present a button design that has been optimized via material selection and component geometry to minimize both the trapped mode heating and the resulting thermal distortion

Parity assignments in 172,174Yb using polarized photons and the K quantum number in rare earth nuclei

The 100 % polarized photon beam at the High Intensity gamma-ray Source (HIgS) at Duke University has been used to determine the parity of six dipole excitations between 2.9 and 3.6 MeV in the deformed nuclei 172,174 Yb in photon scattering (g,g') experiments. The measured parities are compared with previous assignments based on the K quantum number that had been assigned in Nuclear Resonance Fluorescence (NRF) experiments by using the Alaga rules. A systematic survey of the relation between gamma-decay branching ratios and parity quantum numbers is given for the rare earth nuclei.Comment: 5 pages, 6 figures, to be published in Phys. Rev.

Instrumentation for the proposed low energy RHIC electron Cooling project

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Mechanical Activation of the Phosphorites (Karatau Pool) by using Organic-Mineral Co-Activators for Multicomponent Mineral Fertilizers

Deficiency of mineral fertilizers in the agricultural sector for last 15–20 years has decreased. Therefore with the purpose of partial reduction of this deficiency it was developed a new polycomponent NPK fertilizer, which contains humate and vermiculite. The given fertilizer has been produced from the natural South Kazakhstan raw materials in accordance with an acid-free way. The given article contains the data and physicochemical properties of initial materials prepared on the basis of phosphorite fines of Zhanatas and Chulaktau deposits and sinter return. Characteristics of vermiculite and the internal overburden rocks formed at the mining brown coal on the Lenger deposit are represented. During the experimental research except the above-stated natural raw materials the following substances were used at manufacture of the  polycomponent fertilizer: ammonia saltpeter, ammonium sulphate produced by the OJSC “Grodno-Azot”, halurgical potassium chloride produced by “Belaruskaliy” and potassium hydroxide, a chemical reagent of a grade “pure”. The given article contains the data about the chemical composition of initial raw materials and conditions of mechanical-chemical activation of the initial materials at various values of components concentration, temperature and time at the polycomponent fertilizer manufacture. The plan and research results of phosphorite’s activation with the analysis of a disperse structure of nonactivated and activated Zhanatas phosphorite are represented. The determination of nonactivated and activated phosphorites specific surface was performed with use of a device PSH-8A according to the method based on the measurement of hydraulic resistance of a powder material’s layer at filtration of an air low-pressure stream

Conceptual Design of the NSLS-II Injection System.

We present the conceptual design of the NSLS-II injection system [1,2]. The injection system consists of a low-energy linac, booster and transport lines. We review two different injection system configurations; a booster located in the storage ring tunnel and a booster housed in a separate building. We briefly discuss main parameters and layout of the injection system components

NSLS-II Beam Diagnostics Overview

A new 3rd generation light source (NSLS-II) is in the early stages of construction at Brookhaven National Laboratory. The NSLS-II facility will provide ultra high brightness and flux with exceptional beam stability. It presents several challenges for diagnostics and instrumentation, related to the extremely small emittance. In this paper, we present an overview of all planned instrumentation systems, results from research and development activities; and then focus on other challenging aspects

Proof-of-Principle Experiment for FEL-Based Coherent Electron Cooling,”

Abstract Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, highintensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC

Wake fields due to wall roughness for realistic surfaces

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