Development of beam position monitors for heavy ion recirculators
Work is underway at the Lawrence Livermore National Laboratory to design and build a small-scale, heavy ion recirculating induction accelerator. An essential part of this design work is the development of small non-intercepting diagnostics to measure beam current and position. This paper describes some of this work, with particular emphasis on the development of a small capacitive probe beam position monitor to resolve beam position to the 100 /spl mu/m level in a 6 cm diameter beam pipe. Initial measured results with an 80 keV potassium ion beam are presented.
Diagnostics for intense heavy ion beams in the HIF-VNL
Th.I-10 DIAGNOSTICS FOR INTENSE HEAVY ION BEAMS IN THE HIF-VNL* F. M. Bieniosek † , S. Eylon † , A. Faltens † , A. Friedman ‡ , J.W. Kwan † , M.A. Leitner † , A.W. Molvik ‡ , L. Prost † , P.K. Roy † , P.A. Seidl † , G. Westenskow ‡ Lawrence Berkeley National Laboratory, Berkeley, CA, USA and HIF-VNL Lawrence Livermore National Laboratory, Livermore, CA, USA and HIF-VNL Abstract Modern diagnostic techniques provide detailed information on beam conditions in injector, transport, and final focus experiments in the HIF-VNL. Parameters of interest include beam current, beam energy, transverse and longitudinal distributions, emittance, and space charge neutralization. Imaging techniques, based on kapton films and optical scintillators, complement and in some cases, may replace conventional techniques based on slit scans. Time-resolved optical diagnostics that provide 4-D transverse information on the experimental beams are in operation on the existing experiments. Current work includes a compact optical diagnostic suitable for insertion in transport lines, improved algorithms for optical data analysis and interpretation, a high-resolution electrostatic energy analyzer, and an electron beam probe. A longitudinal diagnostic kicker generates longitudinal space-charge waves that travel on the beam. Time of flight of the space charge waves and an electrostatic energy analyzer provide an absolute measure of the beam energy. Special diagnostics to detect secondary electrons and gases desorbed from the wall have been developed. * This work performed under the auspices of the U.S Department of Energy by University of California, Lawrence Livermore and Lawrence Berkeley National Laboratories under contracts No. W-7405-Eng-48 and DE-AC03-76SF00098. Corresponding author: Frank Bieniosek Lawrence Berkeley National Laboratory 1 Cyclotron Road Bldg 47R0112 Berkeley, CA, 94720-8201 USA Tel: 510-486-4245 Fax: 510-486-5392 Email: fmbieniosek@lbl.gov
Characterization of ceramic composite membrane filters for hot gas cleaning
Abstract Novel composite ceramic membrane filters suitable for hot gas cleaning operations have been prepared from fly ash and titania particles on stainless steel woven mesh substrates. Both membranes had a structure like a solid packed bed with a thickness of less than 100 μm. In the domain of laminar flow, significant differences in the pressure drop between experimental results and those predicted from the Kozeny-Carman relationship were found, particularly for flow through the titania membrane. Membrane filters with extremely small pores such as the titania membrane are greatly affected by slip up to 80% in permeability at elevated temperatures. Efficiencies of filtration of typical coal fired power station exhaust fly ashes were found to be greater than 909% for both titania and ash membranes, whilst there was greater variation in the pressure drops in the ash membrane than in the titania at typical gas flows.