Far-Tech, Inc., San Diego, California, USA
BNL, Upton, Long Island, New York, USA
To model the dynamics of the ions in an Electron Beam Ion Source (EBIS), a time-dependent, self-consist particle-in-cell Monte Carlo code (EBIS-PIC) has been developed by FAR-TECH, Inc. The energetic background electron beam is modeled by PBGUNS (http://www.far-tech.com/pbguns/index.html) by dividing the long beam path into several segments to resolve the big length-to-radius spatial scaling problem. The injected primary ions and ionized neutral gas ions are tracked using Monte Carlo method which includes the ionization, charge-exchange and Coulomb collisions with the electron beam and the neutral gas in the potential well, which is calculated by solving the Poisson equation each time step. EBIS-PIC has been able to predict the spatial and velocity space distributions and the evolution of the charge state distribution (CSD) of trapped ions in EBIS devices operating in fast or slow trapping mode. The physical model of EBIS-PIC code and the simulations of the trapping and charge-breeding of injected Cs+1 ions on the Test EBIS* at BNL will be presented. The simulation results have shown good consistency with the experiments.
* S. Kondrashev, J.G. Alessi, E.N.Beebe, C. Dickerson, P.N.Ostroumov, A. Pikin, G. Savard, NIMPR. A, 642 (2011), 18-24.
BNL, Upton, Long Island, New York, USA
A method to increase the ion beam intensity of RHIC EBIS by extending its ion trap into magnetic field of an additional superconducting solenoid is described. The strong axial support of the cold masses in these solenoids is required to place them on a common axis close to each other. Such configuration of solenoids allows to produce a long EBIS with a single electron gun, electron collector and injection system. Preliminary calculations of magnetic forces, magnetic field and potential distributions are presented along with proposed structure of the ion traps.
BNL, Upton, Long Island, New York, USA
Electron beam ion sources (EBIS) and its variants such as the electron beam ion trap (EBIT) and electron string ion source (ESIS) have been selected to provide highly charged ions for several atomic and nuclear physics facilities. Since the capture and breeding can be short and highly efficient, EBIST devices are increasingly being chosen for trapping and/or reacceleration of radioactive beams. The sources can range from petite to grand, using electron beams from ~1mA to 10A or more. They often serve accelerators and beam lines in large laboratories but they can be self contained laboratories where experiments are made in situ. We will discuss the basic principles as well as applications of these sources at various facilities around the world. Some emphasis will be placed on the recently commissioned RHIC EBIS source which is now providing beams for both high energy physics at the relativistic heavy ion collider as well as the NASA space radiation laboratory at BNL.
