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PST01 |
Implementation and Operation of Electron Cloud Diagnostics for CesrTA
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vacuum, electron, quadrupole, pick-up |
83 |
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- Y. Li, X. Liu, V. Medjidzade, J. Conway, M. Palmer
Cornell University - CLASSE
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The vacuum system of Cornell Electron Storage Ring (CESR) was successfully reconfigured to support CesrTA physics programs, including electron cloud (EC) build-up and suppression studies. One of key features of the reconfigured CESR vacuum system is the flexibility for exchange of various vacuum chambers with minimized impact to the accelerator operations. This is achieved by creation of three short gate-valve isolated vacuum sections. Over the last three years, many vacuum chambers with various EC diagnostics (such as RFAs, shielded pickups, etc) were rotated through these short experimental sections. With these instrumented test chambers, EC build-up was studied in many magnetic field types, including dipoles, quadrupoles, wigglers and field-free drifts. EC suppression techniques by coating (TiN, NEG and a-C), surface textures (grooves) and clearing electrode are incorporated in these test chambers to evaluate their effectiveness. We present the implementation and operations of EC diagnostics.
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MOD04 |
Modeling Electron Cloud Buildup and Microwave Diagnostics using VORPAL
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electron, simulation, plasma, higher-order-mode |
162 |
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- S. Veitzer, P. Stoltz
Tech-X Corporation
- K. Sonnad
Cornell University - CLASSE
- P. Lebrun
Fermilab
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We present an overview of recent electron cloud modeling results using the multi-dimensional, parallel, plasma simulation code VORPAL. We have used VORPAL to model cloud buildup in dipole, quadrupole, and field-free magnetic field configurations, in both circular and elliptical cross section pipes relevant to microwave diagnostics at the PEP-II experiment at SLAC, and ongoing experiments in the Main Injector at Fermilab. In addition, we present preliminary results for modeling electron orbits in the CesrTA wiggler, which is the beginning of a more detailed modeling effort to understand electron cloud effects in electron/positron accelerators, as well as connecting microwave side-band measurements to cloud densities. We also report on recent 3-Dimensional microwave transmission simulations through uniform and non-uniform clouds, and with higher order TE and TM waves using VORPAL.
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Slides
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DIA04 |
Status of COLDDIAG: a Cold Vacuum Chamber for Diagnostics
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electron, vacuum, synchrotron, radiation |
190 |
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- S. Gerstl, T. Baumbach, S. Casalbuoni, A. Grau, M. Hagelstein, D. Saez de Jauregui
Karlsruhe Institute of Technology
- R. Cimino, M. Commisso, B. Spataro, A. Mostacci
INFN/LNF
- J. Clarke, D. Scott
Science and Technology Facilities Council (STFC/DL/ASTeC) Daresbury Laboratory Accelerator Science and Technology Centre
- M. Cox, J. Schouten
Diamond Light Source Ltd (Diamond)
- R. Jones, I. Shinton
Cockcroft Institute
- E. Wallen
Lund University - MAX-Lab
- R. Weigel
Max-Planck Institute for Metal Research, Stuttgart
- V. Baglin
CERN
- C. Boffo, G. Sikler
Babcock Noell GmbH (BNG)
- T. Bradshaw
Science and Technology Facilities Council (STFC/RAL) Rutherford Appleton Laboratory
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One of the still open issues for the development of superconducting insertion devices is the understanding of the heat load induced by the beam passage. With the aim of measuring the beam heat load to a cold bore and in order to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. We plan to have access with the same set-up to a number of different diagnostics, so we are implementing: i) retarding field analyzers to measure the electron flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. COLDDIAG is built to fit in a short straight section at ANKA, but we are proposing its installation in different synchrotron light sources with different energies and beam characteristics. A first installation in DIAMOND is planned in June 2011. Here we describe the technical design report of this device and the planned measurements with beam.
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Slides
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