Muons, Inc, Batavia, USA
JLAB, Newport News, Virginia, USA
Illinois Institute of Technology, Chicago, Illinois, USA
The G4beamline program is a useful and steadily improving tool to quickly and easily model beam lines and experimental equipment without user programming. It has both graphical and command-line user interfaces. Unlike most accelerator physics codes, it easily handles a wide range of materials and fields, being particularly well suited for the study of muon and neutrino facilities. As it is based on the Geant4 toolkit, G4beamline includes most of what is known about the interactions of particles with matter. We are continuing the development of G4beamline to facilitate its use by a larger set of beam line and accelerator developers. A major new feature is the calculation of space-charge effects. G4beamline is open source and freely available.
JLAB, Newport News, Virginia, USA
Muons, Inc, Batavia, USA
RPI, Troy, New York, USA
ODU, Norfolk, Virginia, USA
We have performed three-dimensional simulations of beam dynamics for parallel-bar transverse electromagnetic mode (TEM) type RF separators: normal- and superconducting. The compact size of these cavities as compared to conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of eight 2-cell normal conducting cavities or a one- or two-cell superconducting structure are enough to produce the required vertical displacement at the Lambertson magnet. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.
University of Connecticut, Storrs, Connecticut, USA
JLAB, Newport News, Virginia, USA
JLAB, Newport News, Virginia, USA
ODU, Norfolk, Virginia, USA
Crab crossing of colliding electron and ion beams is essential for accommodating the ultra high bunch repetition frequency in the conceptual design of MEIC – a high luminosity polarized electron-ion collider at Jefferson Lab. The scheme eliminates parasitic beam-beam interactions and avoids luminosity reduction by restoring head-on collisions at interaction points. In this paper, we report simulation studies of beam dynamics with crab cavities for MEIC design. The detailed study involves full 3-D simulations of particle tracking through the various configurations of crab cavities for evaluating the performance. To gain insight, beam and RF dominated fields with other parametric studies will be presented in the paper.
JLAB, Newport News, Virginia, USA
In this paper, we report the first study of beam related instabilities in lepton ring of the proposed electron-ion collider beyond the 12 GeV upgrade of CEBAF at Jefferson lab. The design parameters are consistent with PEP-II. Present studies reveal that coupled bunch and two stream instabilities are important issues and we need feedback system.
JLAB, Newport News, Virginia, USA
University of Connecticut, Storrs, Connecticut, USA
JLAB, Newport News, Virginia, USA
Northern Illinois University, DeKalb, Illinois, USA
Cockcroft Institute, Warrington, Cheshire, United Kingdom
GOO Zaryad, Novosibirsk, Russia
ANL, Argonne, USA
ODU, Norfolk, Virginia, USA
SLAC, Menlo Park, California, USA
An electron-ion collider (MEIC) is envisioned as the primary future of the JLab nuclear science program beyond the 12 GeV upgraded CEBAF. The present MEIC design selects a ring-ring collider option and covers a CM energy range up to 51 GeV for both polarized light ions and un-polarized heavy ions, while higher CM energies could be reached by a future upgrade. The MEIC stored colliding ion beams, which will be generated, accumulated and accelerated in a green field ion complex, are designed to match the stored electron beam injected at full energy from the CEBAF in terms of emittance, bunch length, charge and repetition frequency. This design strategy ensures a high luminosity above 1034 s−1cm-2. A unique figure-8 shape collider ring is adopted for advantages of preserving ion polarization during acceleration and accommodation of a polarized deuteron beam for collisions. Our recent effort has been focused on completing this conceptual design as well as design optimization of major components. Significant progress has also been made in accelerator R&D including chromatic correction and dynamical aperture, beam-beam, high energy electron cooling and polarization tracking.