PAC07 - List of Keywords (octupole)

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octupole

Paper	Title	Other Keywords	Page
MOPAN086	Final Geometry of 1232 LHC Dipoles	dipole, controls, target, superconductivity	359
	E. Y. Wildner M. Bajko, P. Bestmann, S. D. Fartoukh, J. B. Jeanneret, D. P. Missiaen, D. Tommasini CERN, Geneva
	The 15 m long main dipoles for the Large Hadron Collider are now being installed in their final positions in the accelerator tunnel. Geometric measurements of the magnets after many of the production steps from industry to the cryostating, after cold tests and after preparation of the magnets for installation, have been made, permitting careful control of the shape of the magnet, the positioning of the field correctors, and the final positioning in the tunnel. The result of the geometry control at the different production stages, from industry to CERN, using different kinds of control procedures and analysis, will be reported.

TUPAN035	Reduction of the Non-Linearities in the DAPHNE Main Rings Wigglers	wiggler, multipole, simulation, quadrupole	1463
	S. Bettoni S. Guiducci, M. A. Preger, P. Raimondi, C. Sanelli INFN/LNF, Frascati (Roma)
	The wigglers of the DAPHNE main rings have been the main source of non-linearities for the beam dynamics in the collider. This paper describes a method to reduce the integrated odd multipoles (the even ones tend to vanish for the periodicity of the magnet) by alternatively displacing the magnetic axis of the poles to compensate the integrated odd multipoles in each half-period of the wiggler. In order to check the effectiveness of this approach, tracking studies have been performed. Tracking results have been used to tune the MAD model of the wiggler.

TUPAN079	Scheme for Flattening of Ion Density Distribution on a Target	target, ion, quadrupole, simulation	1556
	N. Yu. Kazarinov G. Gulbekyan, V. I. Kazacha, V. N. Melnikov, V. I. Mironov JINR, Dubna, Moscow Region
	A scheme for flattening of the ion density distribution on a target is considered. The aim is to obtain the ion density distribution with deviation from the medium level not more than 5% on the target having rather big dimensions (up to ~60 cm in width and ~30 cm in height). Such kinds of targets are required for some technological purposes. The Xe ion beam extracted from a cyclotron has the following parameters: mass-to-charge ratio is 4.4, the kinetic energy is 4.2 MeV per nucleon, the beam current is 1 and the beam emittance is equal to 40 mm mrad. The ion beam line consists of quadrupoles doublet and oqtupole lens. After passimg through two quadrupoles the ion beam has big horizontal and small vertical dimensions. After that the oqtupole makes the horizontal ion beam density distribution on the target uniform withing the nessary demands. The geometry of the beam line, the quadrupole and oqtupole lens parameters are found during simulation. The simulated final beam density distribution on the target is also given.

TUPAS046	Uniform Beam Intensity Redistribution in the LENS Nonlinear Transport Line	target, proton, beam-transport, simulation	1748
	A. Bogdanov V. Anferov, M. Ball, D. V. Baxter, V. P. Derenchuk, A. V. Klyachko, T. Rinckel, K. A. Solberg IUCF, Bloomington, Indiana
	Funding: The LENS project is supported by the NSF (grants DMR-0220560, DMR-0242300), the 21st Century Science and Technology fund of Indiana, Indiana University, and the Department of Defense The Low Energy Neutron Source (LENS) at Indiana University is producing neutrons by using a 7 MeV proton beam incident on a Beryllium target. The Proton Delivery System is currently being upgraded. A new DTL section will be added to increase proton beam energy from 7 to 13 MeV. A 3 MeV RFQ and 13 MeV DTL will be powered by 1 MW klystrons. The goal of this upgrade is a 13 MeV, 20 mA proton beam with duty factor more than 1%. At this power level it becomes increasingly important to make a proton beam that is uniformly distributed to prevent excessive thermal stress at the surface of the Be target. To achieve this goal two octupole magnets are being implemented in the LENS beam transport line. In this paper we discuss the experimental results of the beam intensity redistribution as well as some features inherent in tuning of the nonlinear beamline and our operational experience.

WEOAC03	Transverse Impedance of LHC Collimators	impedance, injection, collimation, insertion	2003
	E. Metral G. Arduini, R. W. Assmann, A. Boccardi, T. Bohl, C. B. Bracco, F. Caspers, M. Gasior, O. R. Jones, K. K. Kasinski, T. Kroyer, S. Redaelli, G. Robert-Demolaize, G. Rumolo, R. J. Steinhagen, Th. Weiler, F. Zimmermann CERN, Geneva F. Roncarolo UMAN, Manchester B. Salvant EPFL, Lausanne
	The transverse impedance in the LHC is expected to be dominated by the numerous collimators, most of which are made of Fibre-Reinforced-Carbon to withstand the impacts of high intensity proton beams in case of failures, and which will be moved very close to the beam, with full gaps of few millimetres, in order to protect surrounding super-conducting equipments. We present an estimate of the transverse resistive-wall impedance of the LHC collimators, the total impedance in the LHC at injection and top energy, the induced coupled-bunch growth rates and tune shifts, and finally the result of the comparison of the theoretical predictions with measurements performed in 2004 and 2006 on a prototype collimator installed in the SPS.
	Slides

THPMS091	The Superconducting Magnets of the ILC Beam Delivery System	superconducting-magnet, extraction, dipole, background	3196
	B. Parker M. Anerella, J. Escallier, P. He, A. K. Jain, A. Marone BNL, Upton, Long Island, New York Y. Nosochkov, A. Seryi SLAC, Menlo Park, California
	Funding: Work supported by the US Department of Energy under contract DE-AC02-98CH10886. A wide variety of superconducting magnets are needed in the ILC Beam Delivery System (BDS) to maximize luminosity and minimize experimental backgrounds. Compact final focus quadrupoles and multifunction correction coils are used with 14 mr total crossing angle to focus incoming beams to few nanometer spot sizes while focusing outgoing disrupted beams into a separate extraction beam line. Large aperture anti-solenoids correct deleterious nonlinear effects that arise due to the overlap of focusing fields with the main detector solenoid. Far from the interaction point (IP) sets of strong small aperture octupoles help minimize backgrounds at the IP due to beam halo particles while weak large aperture dipoles integrated with the experimental detector reduce backgrounds due to beamstrahlung pairs generated at the IP. The physics requirements and magnetic design solutions for these magnets are reviewed in this paper.

THPAN018	Stability Thresholds for Transverse Dipole Modes with Nonlinear Space Charge, Chromaticity and Octupoles	space-charge, simulation, impedance, damping	3262
	V. Kornilov O. Boine-Frankenheim, I. Hofmann GSI, Darmstadt
	Funding: Work supported by EU design study (contract 515873 -DIRACsecondary-Beams) Transverse stability due to combinations of chromaticity effect, nonlinear space charge and octupoles of different polarities plays an important role in the determination of the impedance budget for the FAIR synchrotrons. Different analytic approaches [,,etc.] have been suggested, for which no direct comparison has been made so far. In order to clarify this issue we perform numerical investigations employing the particle tracking code PATRIC and compare results of simulation scans with predictions of a dispersion relation. Space charge effects within self-consistent and 'frozen' models are used for comparisons, connection to beam transfer function studies is addressed. D. Moehl, CERN/PS 95-08 (DI), (1995)** M. Blaskiewicz, Phys. Rev. ST Accel. Beams 4, 044202, (2001)

THPAN027	The Optimum Chromaticity Correction Scheme for Monochromatic and Non-Monochromatic Beam in HESR	sextupole, lattice, multipole, quadrupole	3286
	A. N. Chechenin Y. Senichev, N. E. Vasyukhin FZJ, Julich
	The High Energy Storage Ring (HESR) of FAIR project consists of two achromatic arcs and two dispersionless straight sections. Due to the multi-functional purpose of the straight sections their contribution into the total chromaticity of the first and second order exceeds the arc's contribution and can affect on the non-monochromatic beam dynamic aperture. We investigate the optimum sextupole and octupole correction scheme for monochromatic and non-monochromatic beam to reach the larger dynamic aperture.

THPAS102	Uniform Beam Distributions at the Target of the NSRL Beam Transfer Line	target, ion, booster, beam-transport	3720
	N. Tsoupas L. Ahrens, K. A. Brown, I.-H. Chiang, C. J. Gardner, W. W. MacKay, P. H. Pile, A. Rusek BNL, Upton, Long Island, New York
	Funding: Work supported by the US Department of Energy Uniform irradiation of biological or material samples with charged particle beams is desired by experimentalist because it reduces radiation-dose-errors which are introduced by a non-uniform irradiation of the samples. In this paper we present results of uniform beams produced in the NASA SPACE RADIATION LABORATORY (NSRL) at the Brookhaven National Laboratory (BNL) by a method which was conceived theoretically and tested experimentally at BNL. This method* of producing uniform beams in the transverse beam direction, is based on purely magnetic focusing of the beam and requires no collimation of the beam or any other type of beam interaction with materials. The method is favorably compared with alternative methods** of producing uniform beam distributions normal to the beam direction and can be applied to the whole energy spectrum of the charged particle beams that are delivered by the Booster synchrotron at BNL. Uniform Particle Beam Distribution Produced by Octupole Focusing N. Tsoupas et. al. NSE: 126, 71-79 (1997) *Review of Ion Beam Therapy: Present and Future J. Alonso LBNL EPAC 2000

FRPMN019	The Regular and Random Multi-Pole Errors Influence on the HESR Dynamic Aperture	multipole, sextupole, lattice, quadrupole	3949
	A. N. Chechenin Y. Senichev, N. E. Vasyukhin FZJ, Julich
	The High Energy Storage Ring has the racetrack lattice, where each arc has the even number of super-periods S and the tune with one unit smaller ν=S-1 in both planes. Due to this fundamental feature the total n-order multi-pole is entirely cancelled and the regular errors can be fully compensated inside of one arc. In case of the random multi-pole errors the dynamic aperture is determined by the structure resonances excitation. We consider both regular and random multi-pole influence on the dynamic aperture and the possible correction scheme.

FRPMN078	Improved Algorithms to Determine Non-Linear Optics Model of the SPS from Non-Linear Chromaticity	multipole, injection, simulation, optics	4231
	R. Tomas G. Arduini, G. Rumolo, F. Zimmermann CERN, Geneva R. Calaga BNL, Upton, Long Island, New York A. Faus-Golfe IFIC, Valencia
	Funding: This work is partially supported by the U. S. DOE In recent years several measurements of the SPS non-linear chromaticity have been performed in order to determine the non-linear optics model of the SPS machine at injection energy for different cycles. In 2006 additional measurements have been performed at injection and during the ramp for the cycle used to accelerate the LHC beam. New and more robust matching algorithms have been developed in 2006 to fit the model to the measurements up to arbitrary chromatic order. In this paper we describe the algorithms used in the analysis of the data and we summarize and compare the results from all experiments.

FRPMS010	Electron Cloud in the Fermilab Booster	electron, space-charge, booster, impedance	3895
	K. Y. Ng
	Simulations reveal a substantial build up of electron cloud in the Fermilab Booster ramping cycle, both inside the unshielded combined-function magnets and the beam pipes joining the magnets. The neutralization can be appreciable depending on the second-emission yield of the magnet pole faces and the beam pipe surfaces. The implication of the electron-cloud effects on the beam emittances and collective instabilities is discussed.