lattice

Paper	Title	Other Keywords	Page
MOP43	The Impact of Longitudinal Drive Beam Jitter on the CLIC Luminosity	linac, luminosity, feedback, simulation	138
	D. Schulte, E. J. N. Wilson, F. Zimmermann CERN, Geneva
	In the compact linear collider (CLIC) now under study at CERN, the RF power which accelerates the main beam is provided by decelerating a high current drive beam. Errors in the timing and intensity of the drive beam can turn into RF phase and amplitude errors that are coherent along the whole main linac and the resulting error of the final beam energy, in combination with the limited bandwidth of the beam delivery system, can lead to a significant loss of luminosity. We discuss the stability tolerances that must be applied to the drive beam to avoid this loss. We also examine one of the most important sources of this jitter, which stems from the combination of RF jitter in the drive beam accelerator and subsequent bunch compression. Finally we give details of a potential feedback system that can reduce the drive beam jitter.
MOP86	Cold Test Results of the ISAC-II Medium Beta High Gradient Cryomodule	coupling, alignment, acceleration, linac	222
	R.E. Laxdal, Y. Bylinskii, G.S. Clark, K. Fong, A.K. Mitra, R. L. Poirier, B. Rawnsley, T. Ries, I. Sekatchev, G. Stanford, V. Zvyagintsev TRIUMF, Vancouver
	Many proposals (RIA, Eurisol, ISAC-II) are emerging for a new generation of high gradient heavy ion accelerators. The ISAC-II medium beta cryomodule represents the first realized application that encorporates many new techniques to improve the performance over machines presently being used for beam delivery. The machine lattice, compatible with multi-charge acceleration, uses high field (9T) superconducting solenoids with bucking coils for active fringe field compensation. The bulk niobium quarter wave medium beta cavity produces 6 MV/m over an effective length of 18cm with a peak surface field of ~30 MV/m. TRIUMF has developed a mechanical tuner capable of both coarse (kHz) and fine (Hz) frequency adjustments of the cavity. The demonstrated tuner resolution is better than 0.1 μm (0.6 Hz). A new rf coupling loop has been developed that operates at 200 Watts forward power with less than 0.5 Watt of power being added to the helium load. Cold alignment in ISAC-II has been done with rf pick-ups using a stretched wire technique. Finally all cryomodule and testing has been done in a clean environment. The alignment cryogenic, solenoid and rf performance will be presented.
	Transparencies
TUP67	Beam-Based Alignment Measurements of the LANSCE Linac	injection, focusing, quadrupole, linac	420
	R.C. McCrady, L. Rybarcyk LANL, Los Alamos, New Mexico
	We have made measurements of the alignment of the LANSCE Drift Tube linac (DTL) and Side Coupled linac (SCL) using beam position measurements and analyzing them with linear models. In the DTL, we varied the injection steering, measured the beam position after each DTL tank, and analyzed the data with a linear model using R-matrices that were computed by the Trace-3D computer program. The analysis model allowed for tank-to-tank misalignments. The measurements were made similarly in the SCL, where the analysis model allowed for misalignments of each quadrupole doublet lens. We present here the analysis techniques, the resulting alignment measurements and comparisons to measurements made with optical instruments.