Author: Malysheva, L.I.
Paper Title Page
TUPC004 The Luminosity for the ILC Travelling Focus Regime with Offsets and Angle Scans* 991
 
  • L.I. Malysheva, O.S. Adeyemi, V.S. Kovalenko, A. Ushakov
    University of Hamburg, Hamburg, Germany
  • K. Buesser, A.F. Hartin, G.A. Moortgat-Pick, N.J. Walker
    DESY, Hamburg, Germany
  • S. Riemann, F. Staufenbiel
    DESY Zeuthen, Zeuthen, Germany
 
  One of the crucial challenges of a future linear collider is to provide high luminosity. In the current ILC design a luminosity of 2x1034 is foreseen. In order to enhance the luminosity, use of the “travelling focus” scheme is under discussion. Within this regime the hourglass effect at the interaction point can be effectively overcome by judiciously arranging for the head and tail of the bunches to be focused at a proportionally displaced longitudinal position. The effect is further enhanced by the strong beam-beam interaction which continuously focuses the bunches during collision. In principle travelling focus could provide an additional 30% luminosity. Nevertheless the regime is highly sensitive to beam-beam transverse and angular offsets at the collision point. The study of the luminosity stability for various ILC parameters using traveling focus will be presented.  
 
TUPC005 Evolution of Pressure in Positron Source for Future Linear e+e Collider 994
 
  • O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva
    University of Hamburg, Hamburg, Germany
  • A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov
    DESY, Hamburg, Germany
  • A. Schälicke, F. Staufenbiel
    DESY Zeuthen, Zeuthen, Germany
 
  Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.
 
 
TUPC006 Production of Highly Polarized Positron Beams* 997
 
  • A. Ushakov, O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva, G.A. Moortgat-Pick
    University of Hamburg, Hamburg, Germany
  • A.F. Hartin
    DESY, Hamburg, Germany
  • S. Riemann, A. Schälicke, F. Staufenbiel
    DESY Zeuthen, Zeuthen, Germany
 
  Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Using of polarized electron and positron beams significantly increases the physics potential of future linear colliders. The generation of an intense and highly polarized positron beam is a challenge. The undulator-based positron source located at the end of electron linac is the baseline source for the International Linear Collider. In case of a 250 GeV drive beam energy, an helical undulator with K = 0.92, an undulator period of 11.5 mm and a titanium alloy target of 0.4 radiation length thickness, the average polarization of the generated positrons is relatively low (about 22 percent). In this contribution, the possibilities of increasing the positron polarization have been considered by adjusting the undulator field and selecting those photons and positrons that yield a highly polarized beam. The detailed simulations have been performed with our developed Geant4-based application PPS-Sim*.
* http://pps-sim.desy.de