Author: Droba, M.
Paper Title Page
TUPPC007 Electron Cloud Dynamics in a Gabor Space Charge Lens 1164
  • K. Schulte, M. Droba, B. Glaeser, S. Klaproth, O. Meusel, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  Inside Gabor space charge lenses, external fields confine electrons forming a homogeneously distributed electron cloud. Its linear electric space charge field enables the focusing of high intensity heavy ion beams without aberrations. The focusing performance depends on the properties of the non-neutral plasma. In a small-scale table top experiment, different types of space charge lenses are used to characterize the collective behavior of the confined electron cloud using new non-interceptive diagnostic methods. The plasma parameters, e.g. electron temperature and density, are important to an improved understanding of loss and production mechanisms as well as the electron cloud dynamics. In this context, the evolution of instabilities caused by the enclosing fields has been investigated in detail. Experimental results will be presented and compared to numerical simulations.  
WEPPP016 De-neutralization of Laser Produced Proton Pulse in a Strong Solenoidal Magnetic Field 2755
  • M. Droba, O.K. Kester, O. Meusel, C. Wiesner
    IAP, Frankfurt am Main, Germany
  Laser generated proton pulses of ten to several ten MeV produced in PHELIX-laser facility at GSI Darmstadt poses some unique characteristics. The first systematic exploration of the interface between proton pulse generation via the TNSA mechanism and conventional accelerator technology is within the scope of the LIGHT (Laser Ion Generation, Handling and Transport) project. One of the main tasks is to study the beam dynamics in intense B-fields, especially in context of early de-neutralization and space charge effects. The 3D numerical simulations with co-moving electrons and up to 107 macroparticles were performed to investigate the de-neutralization process in the focusing magnetic solenoid. Importance of the first focusing element and influence on beam parameters will be addressed. Results of the 3D simulation model will be presented and discussed.  
THPPP074 Chopping High Intensity Proton Beams Using a Pulsed Wien Filter 3907
  • C. Wiesner, L.P. Chau, H. Dinter, M. Droba, O. Meusel, I. Müller, D. Noll, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  Chopping high intensity beams at low energies poses substantial challenges. A novel ExB chopper system for proton beams of up to 200 mA at energies of 120 keV is being developed for the accelerator driven neutron source FRANZ*. It uses a Wien filter-type ExB configuration consisting of a static magnetic deflection field and a pulsed electric compensation field to deliver 100 ns beam pulses. The setup minimizes the risk of voltage breakdowns and provides secure beam dumping outside the transport line. In order to prevent beam aberrations and emittance growth careful matching of electric and magnetic deflection forces is required. Detailed numerical studies for the field design and their effects on beam transport were conducted. An H-type dipole magnet with special transverse and longitudinal pole contours was manufactured and combined with shielding tubes to shape the magnetic field. The electric field is driven by a HV pulse generator providing ±6 kV at a repetition rate of 250 kHz. Accurate layout of the deflector plates is required in order to tackle the issues of field quality, cooling and spark prevention. Transport simulations and beam deflection experiments are presented.
* U. Ratzinger et al., "The Driver Linac of the Neutron Source FRANZ," Proc. of IPAC2011, WEPS040, P. 2577 (2011).