2,660 research outputs found

    Electron cloud buildup and impedance effects on beam dynamics in the future circular e+e− collider and experimental characterization of thin TiZrV vacuum chamber coatings

    Get PDF
    The Future Circular Collider FCC-ee is a study toward a high luminosity electron-positron collider with a centre-of-mass energy from 91 GeV to 365 GeV. Due to the beam parameters and pipe dimensions, collective effects and electron cloud can be very critical aspects for the machine and can represent the main limitations to its performance. An estimation of the electron cloud build up in the main machine components and an impedance model are required to analyze the induced instabilities and to find solutions for their mitigation. Special attention has been given to the resistive wall impedance associated with a layer of nonevaporable getter (NEG) coating on the vacuum chamber required for electron cloud mitigation. The studies presented in this paper will show that minimizing the thickness of this coating layer is mandatory to increase the single bunch instability thresholds in the proposed lepton collider at 45.6 GeV. For this reason, NEG thin films with thicknesses below 250 nm have been investigated by means of numerical simulations to minimize the resistive wall impedance. In parallel, an extensive measurement campaign was performed at CERN to characterize these thin films, with the purpose of finding the minimum effective thickness satisfying vacuum and electron cloud requirements

    Early Ceramics in Anatolia: Implications for the Production and Use of the Earliest Pottery. The Evidence from Boncuklu Höyük

    Get PDF
    Fragments of possible fired clay found at Boncuklu Höyük, central Turkey, appear to derive from rudimentary vessels, despite the later ninth- and early eighth-millennium cal. bc and thus ‘Aceramic’ dates for the site. This paper will examine the evidence for such fired clay vessels at Boncuklu and consider their implications as examples of some of the earliest pottery in Anatolia. The discussion will examine contextual evidence for the role of these fragments and consider their relative rarity at the site and the implications for the marked widespread adoption of pottery in southwest Asia c. 7000–6700 cal. bc

    The Ka-band high power klystron amplifier design program of INFN

    Get PDF
    In the framework of the Compact Light XLS project, a short ultra-high gradient linearizer working on the third harmonic of the main linac frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all next generation linear accelerators. Actually, ultra-compact normal conducting accelerating structures, operating in the Ka-band are required to achieve ultra-high gradients for research, industrial and medical applications, with electric field ranging from 100 to 150 MV/m. To fulfill these strong requirements, the R&D of a proper Ka-band klystron with high RF power output and a high efficiency is mandatory. This contribution reports the design of a possible klystron amplifier tube operating on the 010 mode at 36 GHz, the third harmonic of the 12 GHz linac frequency, with an efficiency of 42% and a 20 MW RF power output. This contribution discusses also the high-power DC gun, the beam focusing channel and the RF beam dynamics

    Updates on the INFN High Power Ka-band klystron amplifier design program

    Get PDF
    In the framework of the "Compact Light XLS" project, a short ultra-high gradient linearizer working on the third harmonic of the main linac frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all next generation linear accelerators. Actually, ultra-compact normal conducting accelerating structures, operating in the Ka-band regime ranging from 100 to 150 MV/m are required to achieve ultra-high gradients for research, industrial and medical applications. To fulfill these strong requirements, the R&D of a proper Ka-band klystron with RF power output and a high efficiency is mandatory. This contribution reports the design of a possible klystron amplifier tube operating on the TM010 mode at 36 GHz, the third harmonic of the 12 GHz linac frequency, with an efficiency of 42% and a 20 MW RF power output. This contribution discusses also the high-power DC gun, the beam focusing channel and the RF beam dynamics

    Tourism, natural protected areas and open source geospatial technologies.

    Get PDF
    The Covid-19 outbreak has greatly impacted society behaviours fostering proximity tourism and valorising the social role of peri-urban natural protected areas as key locations for outdoor activities. FOSS and FOSS4G can play a critical role to support the value creation for these sites. This work evaluates its application in the context of two different protected areas for the creation of 3D digital products, the monitoring of touristic fluxes and the conduction of parks management activities. To this aim three solutions that copes with the mentioned aspects are presented and gaps, weakness and limitations evaluated. The investigated solutions consists in: the data workflow from survey to 3D rendering using Blender and GIS plugin; the touristic fluxes monitoring system based on a machine learning algorithm for image recognition from captured video data streams and istSOS; and finally the park assets management system which is based on PostGIS and OpenLayers

    Application of Fractional Operators in Physics and Engineering

    Get PDF
    In this paper we present a solution to a fractional integral of order 3/2 with the use of fractional Cauchy-like integral formula. The integral arises during the solution of BiotSavart equation to find the exact analytical solution for the magnetic field components of a solenoid. The integrals are computed by cutting the branch line in order to have an analytic function inside the integral instead of multi-valued operation

    A Short Walk Through the Balkans: The First Farmers of the Carpathian Basin and Adjacent Regions

    Get PDF
    Proceedings del convegno tenuto all'Istituto di Archeologia dlel'Università di Londra, UCL il 20-22 Giugno 2005. Organizzato da M. Spataro, S. Shennan e P. Biagi. Volume edito nella collana Quaderni (12) della Società per la Preistoria e Protostoria della Regione FRiuli-Venezia Giulia

    Electron Gun and Magnetic Systems Studies for a 36 GHz Klystron Amplifier

    Get PDF
    Self consistent analytic and numeric design for a set of innovative electron guns suitable for Ka-band klystrons is proposed in this paper. The proposed electron sources are designed to produces narrow beam with high currents that can be used in devices with critical dimensions. The proposed set of electron gun is destined to high power klystrons to be used as power sources for accelerating structures operating in Ka-Band. This family of accelerators is foreseen to achieve energy gradients around 150 MV/m. A klystron amplifier is being investigated in order to feed a linearizer structure. In this paper different electron gun and beam focusing channel designs are presented
    • …
    corecore