WE1  —  Wednesday Oral Session WE1   (01-Oct-08   08:30—10:30)

Chair: P. Pierini, INFN/LASA, Segrate (MI)

Paper Title Page
WE101 Energy Recovered Linacs 688
 
  • G.A. Krafft
    JLAB, Newport News, Virginia
 
 

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In the last decade, stimulated by the success of the energy recovered free electron lasers, many projects have been initiated exploring the applications and limitations of beam energy recovery in recirculated linear accelerators (linacs). In this talk the performance of many existing energy recovered linacs is briefly reviewed. Looking forward, potential applications of energy recovered linacs such as

  1. recirculated linac light sources,
  2. high energy beam electron cooling devices, and
  3. electron beam sources for high energy colliders have been pursued with varying degrees of effort.
The types of new technology that must be developed for applications, and more broadly, some of the open issues regarding this technology, are discussed in detail. The talk concludes with some thoughts on the future developments in this important, and expanding field.

 

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WE102 High Average Current SRF Cavities 693
 
  • T. Furuya
    KEK, Ibaraki
 
 

Higher-order-mode (HOM) free superconducting (SC) single cell cavities were developed for the rf system of high luminosity storage ring colliders. Because of the successful results of these cavities under ampere-class beams, the components and technology of the SC cavities have immediately been applied to the middle sized storage rings upgrading the beam intensity by using a few SC cavities. Beside the storage ring rf, a SC based high intensity proton linac was commissioned for neutron physics. Recently, the feasibility study of energy recovery linacs has been carried at various laboratories aiming for the 4th generation light source. Status of these developments will be described.

 

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WE103 First Results from the ERL Prototype (ALICE) at Daresbury 694
 
  • D.J. Holder
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
 
 

The energy recovery linac prototype at Daresbury is now called ALICE (Accelerators and Lasers In Combined Experiments). This paper presents the results obtained in the past year, including the second (fourth) period of gun commissioning. Following the completion of gun commissioning in November 2007, the dedicated gun diagnostic line was removed and the electron gun attached to the booster cavity and hence the rest of the machine. The paper outlines some of the challenges experienced during the commissioning of both the photoinjector system and the superconducting cavities and presents the current status of the project as well as the very latest results from commissioning during the summer of 2008.

 

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WE104 First Tests of the Cornell University ERL Injector 699
 
  • B.M. Dunham, I.V. Bazarov, S.A. Belomestnykh, M.G. Billing, E.P. Chojnacki, Z.A. Conway, J. Dobbins, R.D. Ehrlich, M.J. Forster, S.M. Gruner, G.H. Hoffstaetter, V.O. Kostroun, Y. Li, M. Liepe, X. Liu, D.G. Ouzounov, H. Padamsee, D.H. Rice, V.D. Shemelin, C.K. Sinclair, E.N. Smith, K.W. Smolenski, A.B. Temnykh, M. Tigner, V. Veshcherevich, T. Wilksen
    CLASSE, Ithaca, New York
 
 

Funding: Work supported by the National Science Foundation under contract PHY 0131508
Cornell University is planning to build an Energy-Recovery Linac (ERL) X-ray facility. The very small electron-beam emittance would produce an X-ray source that is significantly better than any existing storage-ring based light source. One major difference between an ERL and a typical light source is that the final electron beam emittance, and thus the X-ray beam brightness, is determined by the electron injector rather than the storage ring. We are currently constructing and commissioning an injector for an ERL with the goal of demonstrating the low emittances and high beam power required. The injector is designed to accelerate up to 100 mA cw electron bunches of 77 pC/bunch with an energy of 5 MeV (33 mA at 15 MeV) using 1.3 GHz superconducting cavities. A full suite of diagnostics will allow a complete phase space characterization for comparison with simulations and with the requirements. We will describe the current status of the injector along with results, difficulties and challenges to date.

 

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WE105 RF Control of High QL Superconducting Cavities 704
 
  • C. Hovater
    JLAB, Newport News, Virginia
 
 

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In the last 20 years the requirements for rf control has increased as the target use has broadened from electron/ion accelerators for Nuclear and Particle Physics to light sources such as Free Electron Lasers. The increasing requirement of cavity field control to meet the spectral and jitter performance specifications for light sources has led system designers to a more rigorous approach in designing the rf controls. Design attention must be applied not only to the hardware and control algorithms but also to the overall accelerating system to meet performance and cost requirements. As an example, cavity QL in Energy Recovery Linacs (ERL) must be optimized such that the rf controls can accommodate the lowest possible rf power given the background cavity microphonics. This paper presents the status and future directions of high QL superconducting rf control systems.

 

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