TH2A —  Invited Oral Presentations   (13-Sep-12   11:00—12:30)
Chair: S. Fu, IHEP, Beijing, People's Republic of China
Paper Title Page
TH2A01 The ESS Linac Design 768
  • M. Lindroos, H. Danared, C. Darve, D.P. McGinnis, S. Molloy
    ESS, Lund, Sweden
  The European Spallation Source (ESS) is a 5 MW, 2.5 MeV long pulse proton machine. It represents a big jump in power compare to the existing spallation facilities. The design phase is well under way, with the delivery of a Conceptual Design Report expected in 2012, and a Technical Design Report in 2013. Why and how the 5 MW goal influences the parameter choice will be describe.  
slides icon Slides TH2A01 [5.667 MB]  
TH2A02 SPIRAL2 Accelerator Construction Progress 773
  • P. Bertrand, R. Ferdinand
    GANIL, Caen, France
  The SPIRAL2 superconducting accelerator installation starts in 2012. The major components have been tested in the various partner laboratories, and the building construction is well engaged. The management of the interfaces between process and buildings is a strategic point in an underground project with strong space constraints. This contribution will describe the performances of the various components of the SPIRAL2 accelerator, and the methodology put in place in order to insure the integration of the process inside the buildings.  
slides icon Slides TH2A02 [5.441 MB]  
TH2A03 Design and Construction of the Linac4 Accelerating Structures 778
  • F. Gerigk, Y. Cuvet, A. Dallocchio, G. Favre, J.-M. Geisser, L. Gentini, J.-M. Giguet, S.J. Mathot, M. Polini, S. Ramberger, B. Riffaud, C. Rossi, P. Ugena Tirado, M. Vretenar, R. Wegner
    CERN, Geneva, Switzerland
  • E. Kendjebulatov, Ya.G. Kruchkov, A.G. Tribendis
    BINP SB RAS, Novosibirsk, Russia
  • M.Y. Naumenko
    RFNC-VNIITF, Snezhinsk, Chelyabinsk region, Russia
  The Linac4 project at CERN is at an advanced state of construction. Prototypes of the different types of accelerating structures (RFQ, DTL, CCDTL and pi-mode structures) have been built and are presently tested. This paper gives the status of the cavity production and reviews the RF and mechanical design of the various structure types. Furthermore the production and the first test results shall be presented.  
slides icon Slides TH2A03 [2.675 MB]  
TH2A004 Computational Model Analysis for Experimental Observation of Optical Current Noise Suppression Below the Shot-noise Limit 783
  • A. Gover
    University of Tel-Aviv, Faculty of Engineering, Tel-Aviv, Israel
  • A. Nause
    University of Tel Aviv, Tel Aviv, Israel
  Funding: We acknowledge support of the Israel Science Foundation grant
We report first demonstration of optical frequency current shot-noise suppression in a relativistic e-beam. This process is made possible by collective Coulomb interaction between the electrons of a cold intense beam during beam drift, and is essentially a process of longitudinal beam-plasma oscillation.[1] Suppression of beam current noise below the classical “shot-noise” level has been known in the microwave tubes art [2]. This is the first time that it is demonstrated in the optical regime. We predict that the scheme can be extended to the XUV and possibly to shorter wavelengths with further development of technology. The fundamental current shot-noise determines the level of incoherent spontaneous radiation emission from electron-beam optical radiation sources and SASE-FELs [3]. Suppressing shot-noise would make it possible to attain spontaneous emission sub-radiance [4] and surpass the classical coherence limits of seed-injected FELs. The effect was demonstrated by measuring sub-linear growth as a function of current of the OTR Radiation. This finding indicates that the beam charge homogenizes due to the collective interaction, and its distribution becomes sub-Poissonian.
[1] A. Gover, E. Dyunin, PRL, 102, 154801, 2009
[2] H. Haus, N. Robinson, Proc. IRE, 43, 981 (1955)
[3] P. Emma, et al , Nature Photonics 4, 641 (2010)
[4] A. Dicke, Phys. Rev. 93, 99 (1954)