ORNL RAD, Oak Ridge, Tennessee, USA
The transverse feedback system in the Accumulator Ring of the Spallation Neutron Source~(SNS) is intended to damp broadband (≈40-120~MHz), coherent betatron motion due to e-p interaction. The SNS feedback system is based on an analog delay-line model with some signal conditioning and tuning parameters implemented digitally. This system provides a simple setup with two primary knobs, phase and gain, as well as an equalizer. This simplicity comes at the cost of some flexibility normally found in a standard mode-by-mode design, namely mode-by-mode phase, and gain control. In this paper we discuss the design, tuning, evaluation, and operation of the SNS feedback damper, and discuss the tradeoffs implicit in the design of the system.
TUPM2X01
FRIB, East Lansing, Michigan, USA
BNL, Upton, Long Island, New York, USA
MSU, East Lansing, Michigan, USA
ANL, Argonne, Illinois, USA
The Facility for Rare Isotope Beams being built at Michigan State University includes a high intensity superconducting radio frequency heavy ion linac. This driver linac will accelerate ions up to uranium to energies above 200 MeV/u at 400 kW beam power. The design includes a charge stripper at energies between 16 and 20 MeV/u. The estimated power deposition in a conventional carbon foil stripper would require power densities of the order of 30 MW/cm3. We are developing two types of charge strippers with self-replenishing fluids, a liquid (lithium) and a gas (helium) version. We present in this talk a description of the R&D, the expected pros and cons of each method, and the status of the construction of both systems.
Fermilab, Batavia, Illinois, USA
Fermilab is committed to upgrade its accelerator complex towards the intensity frontier by making a substantial increase in the average beam power delivered to the neutrino and muon programs pursuing HEP research in the lepton sector. Proton Improvement Plan (PIP) enables us to provide 700 kW beam power by the end of this year. By the middle of next decade, the foreseen PIP–II replaces the existing LINAC, a 400 MeV injector to the Booster, by an 800 MeV superconducting LINAC with beam power increased by >50%. In any case, the Fermilab Booster, an 8 GeV injector to the MI, is going to play a very significant role for the next two decades. In this context, we have recently developed an innovative beam injection scheme for the Booster called "early injection scheme" and put into operation. This novel scheme has a potential to increase the Booster beam intensity from the PIP design goal by ~40%. Some benefits of the scheme have already been seen so far. In this talk, I will present, principle of the scheme, results from beam experiments, current status and future plans for the early beam injection scheme. This scheme fits well with the current and future programs at Fermilab.
Author would like to thank S. Chaurize, C. Drennan, F. Garcia, B. Hendrick, W. Pellico, K. Seiya, T. Sullivan, K. Triplett and A. Waller,
TUPM4X01
CERN, Geneva, Switzerland