EPAC 2006 - List of Authors

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Jones, R.M.

Paper	Title	Page
MOPLS071	TDR Measurements in support of ILC Collimator Studies	712
	C.D. Beard, P.A. Corlett, A.J. Moss, J.H.P. Rogers CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R.M. Jones Cockcroft Institute, Warrington, Cheshire
	In this report the outcome of the "wire method" cold test, experimental results and their relevance toward the ILC set-up is considered. A wire is stretched through the centre of a vessel along the axis that the electron beam would take, and a voltage pulse representing the electron bunch is passed along the wire. The parasitic mode loss parameter from this voltage can then be measured. The bunch length for the ILC is 0.3mm, requiring a pulse rise time of ~1ps. The fastest rise time available for a time domain reflectrometry (TDR) scope is ~10ps. Reference vessels have been examined to evaluate the suitability of the test gear at comparable bunch structures to the ILC.
MOPCH163	Analysis of Wakefields in the ILC Crab Cavity	442
	G. Burt, A.C. Dexter Microwave Research Group, Lancaster University, Lancaster C.D. Beard, P. Goudket CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire L. Bellantoni Fermilab, Batavia, Illinois R.M. Jones UMAN, Manchester
	The large crossing angle schemes of the ILC need a correction of bunch orientation at the IP in order to recover a luminosity loss of up to 80%. The orientation of bunches can be changed using a transverse deflecting cavity. The location of the crab cavity would be close to the final focus, and small deflections caused by wakefields in the cavities could cause misalignments of the bunches at the IP. Wakefields in the FNAL CKM cavities have been analysed and their effects studied in view of use as the ILC crab cavity. Numerical simulations have been performed to analyse the transverse wakepotentials of up to quadrupole order modes in this cavity and the effect upon bunches passing through this cavity. Trapped modes within the CKM cavity have been investigated. Perturbation tests of normal conducting models of this cavity have been launched to verify these results. The effect of the final focus quadrupole magnets on the deflection given to the bunch have also been calculated and used to calculate luminosity loss due to wakefields.
MOPLS120	Mitigation of Emittance Dilution due to Transverse Mode Coupling in the L-band Linacs of the ILC	843
	R.M. Jones, R.M. Jones UMAN, Manchester R.H. Miller SLAC, Menlo Park, California
	The main L-band linacs of the ILC accelerate 2820 bunches from a center of mass of 10 GeV to 500 GeV (and in the proposed later upgrade, to 1 TeV). The emittance of the vertical plane is approximately 400 times less than that of the horizontal plane. Provided the vertical and horizontal mode dipole frequencies are degenerate, then the motion in each plane is not coupled. However, in reality the degeneracy will more than likely be removed with the eigen modes lying in planes rotated from the x and y planes due to inevitable manufacturing errors introduced in fabricating 20,000 cavities. This gives rise to a transverse coupling in the horizontal-vertical motion and can readily lead to a dilution in the emittance in the vertical plane. We investigate means to ameliorate this emittance dilution by splitting the horizontal-vertical tune of the lattice.
MOPLS120	Mitigation of Emittance Dilution due to Transverse Mode Coupling in the L-band Linacs of the ILC	843
	R.M. Jones, R.M. Jones UMAN, Manchester R.H. Miller SLAC, Menlo Park, California
	The main L-band linacs of the ILC accelerate 2820 bunches from a center of mass of 10 GeV to 500 GeV (and in the proposed later upgrade, to 1 TeV). The emittance of the vertical plane is approximately 400 times less than that of the horizontal plane. Provided the vertical and horizontal mode dipole frequencies are degenerate, then the motion in each plane is not coupled. However, in reality the degeneracy will more than likely be removed with the eigen modes lying in planes rotated from the x and y planes due to inevitable manufacturing errors introduced in fabricating 20,000 cavities. This gives rise to a transverse coupling in the horizontal-vertical motion and can readily lead to a dilution in the emittance in the vertical plane. We investigate means to ameliorate this emittance dilution by splitting the horizontal-vertical tune of the lattice.
MOPLS066	Direct Measurement of Geometric and Resistive Wakefields in Tapered Collimators for the International Linear Collider	697
	N.K. Watson, D. Adey, M.C. Stockton Birmingham University, Birmingham D.A.-K. Angal-Kalinin, C.D. Beard, J.L. Fernandez-Hernando, F. Jackson CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R. Arnold, R.A. Erickson, C. Hast, T.W. Markiewicz, S. Molloy, M.C. Ross, S. Seletskiy, A. Seryi, Z. Szalata, P. Tenenbaum, M. Woodley, M. Woods SLAC, Menlo Park, California R.J. Barlow, A. Bungau, R.M. Jones, G.Yu. Kourevlev, A. Mercer UMAN, Manchester D.A. Burton, J.D.A. Smith, A. Sopczak, R. Tucker Lancaster University, Lancaster C. Densham, G. Ellwood, R.J.S. Greenhalgh, J. O'Dell CCLRC/RAL, Chilton, Didcot, Oxon Y.K. Kolomensky UCB, Berkeley, California M. Kärkkäinen, W.F.O. Müller, T. Weiland TEMF, Darmstadt N. Shales Microwave Research Group, Lancaster University, Lancaster M. Slater University of Cambridge, Cambridge I. Zagorodnov DESY, Hamburg F. Zimmermann CERN, Geneva
	Precise collimation of the beam halo is required in the ILC to prevent beam losses near the interaction region that could cause unacceptable backgrounds for the physics detector. The necessarily small apertures of the collimators lead to transverse wakefields that may result in beam deflections and increased emittance. A set of collimator wakefield measurements has previously been performed in the ASSET region of the SLAC LINAC. We report on the next phase of this programme, which is carried out at the recently commissioned End Station A test facility at SLAC. Measurements of resistive and geometric wakefields using tapered collimators are compared with model predictions from MAFIA and GdfidL and with analytic calculations.