Tech-X, Boulder, Colorado
ANL, Argonne, Illinois
Euclid TechLabs, LLC, Solon, Ohio
Field Programmable Gate Arrays (FPGAs) offer a powerful alternative to ASICs or general purpose processors in accelerator control applications. Software development for these devices can be awkward and time consuming, however, when using low level hardware design languages. To facilitate the use of FPGAs in control systems we are developing a library of software tools based on ImpulseC, a high level subset of the C language specifically designed for FPGA programming. Development and testing of the software will be performed on a Xilinx Virtex-4 FPGA demo board. We will present timing benchmarks for common control functions (PID feedback loops, FIR and Kalman filters) and present plans for the development of a controller for the Argonne Wakefield Accelerator high current photoinjector based on this work.
BNL, Upton, Long Island, New York
Tech-X, Boulder, Colorado
ORNL, Oak Ridge, Tennessee
AES, Princeton, New Jersey
Fermilab, Batavia, Illinois
Jefferson Lab, Newport News, Virginia
BINP SB RAS, Novosibirsk
JINR, Dubna, Moscow Region
The physics interest in a luminosity upgrade of RHIC requires the development of a cooling-frontier facility. Detailed cooling calculations have been made to determine the efficacy of electron cooling of the stored RHIC beams. This has been followed by beam dynamics simulations to establish the feasibility of creating the necessary electron beam. Electron cooling of RHIC at collisions requires electron beam energy up to about 54 MeV at an average current of between 50 to 100 mA and a particularly bright electron beam. The accelerator chosen to generate this electron beam is a superconducting Energy Recovery Linac (ERL) with a superconducting RF gun with a laser-photocathode. An intensive experimental R&D program engages the various elements of the accelerator: Photocathodes of novel design, superconducting RF electron gun of a particularly high current and low emittance, a very high-current ERL cavity and a demonstration ERL using these components.
Tech-X, Boulder, Colorado
LBNL, Berkeley, California
The standard implementation of using FFTs to solve the Poisson equation with open boundary conditions on a Cartesian grid loses accuracy when the change in G rho (the product of the Green function and the charge density) over a mesh cell becomes nonlinear; this is commonly encountered in high aspect ratio situations and results in poor efficiency due to the need for a very large number of grid points. A modification which solves this problem, the integrated Green function (IGF), has been implemented in two dimensions using linear basis functions and in three dimensions using constant basis functions. But, until recently, it has proved to be very difficult to implement IGF in three dimensions using linear basis functions. Recently significant progress has been made. We present both the implementation and test results for the three-dimensional extension.
Fermilab, Batavia, Illinois
Tech-X, Boulder, Colorado
In the classical head-tail chromaticity measurement technique, a single large kick is applied transversely to the beam. The resulting phase difference between the head and the tail is measured and the chromaticity extracted. In the continuous head-tail kicking technique, a very small transverse kick is applied to the beam and the asymptotic phase difference between the head and the tail is found to be a function of chromaticity. The advantage of this method is that since the tune tracker PLL already supplies the small transverse kicks, no extra modulation is required.
Tech-X, Boulder, Colorado
BNL, Upton, Long Island, New York
LBNL, Berkeley, California
Plans for the RHIC luminosity upgrade call for an electron cooling system that will place substantial demands on the energy, current, brightness, and beam quality of the electron beam. In particular, the requirements demand a new level of fidelity in beam dynamics simulations. New developments in MaryLie/IMPACT have improved the space-charge computations for beams with large aspect ratios and the beam dynamic computations for rf cavities. We present the results of beam dynamics simulations that include the effects of space charge and nonlinearities, and aim to assess the tolerance for errors and nonlinearities on current designs for a super-conducting ERL.