IPAC2013 - List of Keywords (optics)

Paper	Title	Other Keywords	Page
MOODB203	vSTORM Facility Design and Simulation	injection, target, proton, dipole	55
	A. Liu, A.D. Bross, D.V. Neuffer Fermilab, Batavia, USA S.-Y. Lee Indiana University, Bloomington, Indiana, USA
	Funding: Fermi National Accelerator Laboratory A facility producing neutrinos from muons that decay in a storage ring can provide an extremely well understood neutrino beam for oscillation physics and the search for sterile neutrinos. The "neutrinos from STORed Muons"(nuSTORM) facility is based on this idea. The facility includes a target station with secondary particle collection, pion transfer line, pion injection, and a ~3.8 GeV/c muon storage ring. No muon cooling or RF sub-systems are required. The injection scenario for nuSTORM avoids the use of a separate pion decay channel and fast kickers. This paper reports a detailed description of the proposed injection scheme with full G4beamline simulations. We also present progresses on possible design options for a muon racetrack decay ring.
	Slides MOODB203 [14.079 MB]

MOPEA005	A Linear Beam Raster System for the European Spallation Source?	target, linac, quadrupole, beam-losses	70
	H.D. Thomsen, A.I.S. Holm, S.P. Møller ISA, Aarhus, Denmark
	The European Spallation Source (ESS) will, when built, be the most intense neutron source in the world. The neutrons are generated by a high power (5 MW) proton beam impacting a rotating W spallation target. To reduce the replacement frequency of components subjected to the full beam current, i.e. the proton beam window and the target, means to introduce low peak current densities, i.e. flat transverse beam profiles, are necessary. The relatively long beam pulse duration of 2.86 ms (at 14 Hz) leaves ample time to facilitate a Lissajous-like, linear raster system that illuminates a footprint area by sweeping an only moderately enlarged LINAC beamlet. Although slightly more technically challenging, this method has many advantages over the previously envisaged beam expander system based on non-linear DC magnets. The design, specifications, performance, and benefits of the beam raster system will be described and discussed.

MOPEA007	Study of Lower Emittance Optics Using Multi-Bend-Achromat Lattice at SOLEIL	emittance, dipole, lattice, quadrupole	76
	R. Nagaoka, P. Brunelle, X. Gavaldà, M. Klein, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	In the framework of a future upgrade of the SOLEIL 354 m long and 2.75 GeV storage ring, a series of lattice studies has been launched to aim at reducing by an order of magnitude the current 4 nm.rad horizontal emittance. In this exercise, the main constraint imposed is to leave all the existing 24 straight sections for insertion devices untouched. In the previous study (presented at IPAC 2012), the possibility of using superbends and exploiting their longitudinal dipole field variation was pursued in lowering the emittance, finding solutions with a horizontal emittance in the sub nanometer range. In the present study, the use of MBA (Multi-Bend-Achromat) lattice is explored, which is widely recognized today as the optimal lattice in reaching an ultra-low emittance. The study aims to clarify the adaptability of the MBA and the range of attainable emittance for the SOLEIL ring, in view particularly of the short straight sections existing in half of the original DBA cells in between the dipoles. The possibility of combining the previously obtained superbend solutions with the MBA lattice is also examined.

MOPEA012	Lifetime Studies at Metrology Light Source and ANKA	cavity, electron, scattering, septum	88
	T. Goetsch, J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany A.-S. Müller KIT, Karlsruhe, Germany
	The Metrology Light Source (MLS), situated in Berlin (Germany) is an electron storage ring operating from 10⁵ MeV to 630 MeV and is serving as the national primary radiation source standard from the near infrared to the vacuum ultraviolet spectral region. In its standard user mode, the lifetime is dominated by the Touschek effect. Measurements and analysis of the Touschek lifetime as a function of beam current and RF-Voltage will be presented and compared to measurements done at the ANKA electron storage ring (Karlsruhe, Germany) which operates at 0.5 to 2.5 GeV. R. Klein et al., Phys. Rev. ST-AB 11, 110701 (2008) ** A.-S. Müller et al., Energy Calibration Of The ANKA Storage Ring, In Proceedings of EPAC 2004

MOPEA027	New Optics with Emittance Reduction at the SPring-8 Storage Ring	emittance, photon, injection, sextupole	133
	Y. Shimosaki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, T. Nakamura, T. Nakanishi, H. Ohkuma, M. Oishi, M. Shoji, K. Soutome, S. Takano, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	The machine tuning of a new optics is in progress at the SPring-8 storage ring, in order not only to provide brilliant photons for current users but also to study a strategy of a lattice design and a tuning scenario for the upgrade project SPring-8 II. The natural emittance is reduced to 2.4 nmrad from the present value of 3.4 nmrad without any change of magnet positions. The flux density 1.3 times higher than the present was observed at the diagnostics beamline. The nominal injection efficiency of the order of 80 % has been achieved (the present: 92 %) by correcting the error of the optics function, by adjusting the strength of the injection magnets and by optimizing the sextupole magnetic fields. The beam lifetime was 13 h at 1 mA / bunch (the present: 22 h), and the momentum aperture estimated from the measurement of the Touschek lifetime was 2.3 % (the present: 2.8 %). Though these are tolerable to the user operation, further optimization of the sextupoles is ongoing. After verifying the photon beam performance at beamlines, this new optics will be applied to the user operation. The optics design and its beam performance will be presented in detail.

MOPEA045	Performance Optimization and Upgrade of the SSRF Storage Ring	storage-ring, emittance, injection, cavity	178
	Z.T. Zhao, B.C. Jiang, Y.B. Leng, S.Q. Tian, L. Yin, W.Z. Zhang SINAP, Shanghai, People's Republic of China
	The SSRF storage ring achieved its design performance goal in 2008, in the following years its performance was optimized and improved, including implementing top-up operation and low emittance lattice configuration as well as other attempts like fast orbit feedback and low alpha mode. In order to meet the requirements of accommodating more beamlines and high demanding performance in its phase-II beamline project, the SSRF storage ring is being upgraded with a design based on superbend based lattice and a third harmonic RF cavity system. This paper presents the main optimization works and the upgrade design considerations on the SSRF storage ring performance.

MOPEA047	Ramping of the Solaris Storage Ring Achromat	quadrupole, dipole, sextupole, lattice	184
	A.I. Wawrzyniak, C.J. Bocchetta, D. Einfeld, R. Nietubyć Solaris, Kraków, Poland D. Einfeld MAX-lab, Lund, Sweden R. Nietubyć NCBJ, Świerk/Otwock, Poland
	Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program:POIG.02.01.00-12-213/09, The combined function magnets implemented for the MAX IV and Solaris 1.5 GeV storage ring double bend achromats (DBAs) represents a challenging task in magnetic design. The constituent magnets in the DBA block may be sensitive to saturation effects which must be accounted for, especially in the case of energy ramping, as is the case for Solaris and not for MAXIV, where injection will take place at a beam energy of 0.55-0.6 GeV. The magnetic field distribution was calculated as a function of energy in the range from 0.5 GeV up to 1.5 GeV for the gradient dipole and for the quadrupoles containing a sextupole component. Results show that for the dipole, which generates the strongest field, the relative change of quadrupole strength is lower than 4.10^-3. For the quadrupoles the sextupole component is within the relative range of less than 0.7.10-4. The impact on linear and non-linear optics at low energies has been accordingly studied. This is on-going studies and only preliminary results are presented in this paper.

MOPEA066	Investigation and Test of the Possibility of Reducing the Emittance of the Diamond Storage Ring	emittance, lattice, wiggler, injection	234
	B. Singh, M. Apollonio, R. Bartolini, E.C. Longhi Diamond, Oxfordshire, United Kingdom R. Bartolini, T. Pulampong JAI, Oxford, United Kingdom
	Theoretical and experimental studies have been carried out at the Diamond Light Source to assess the possibility of reducing the emittance of the existing storage ring by means of a change to the optics. The optics solutions obtained so far using a Multi Objective Genetic Algorithm (MOGA) increase the dispersion and the horizontal beta function in the straight section. While the emittance can be reduced to 2.1 nm this optics is limited by the operation of high field superconducting wiggler devices. In this report we present details of the new optics and present results of practical tests. We also compare the theoretical emittance growth due to a wiggler in a dispersive region with test results.

MOPEA068	Novel Lattice Upgrade Studies for Diamond Light Source	lattice, vacuum, dipole, quadrupole	240
	R. Bartolini, C.P. Bailey, M.P. Cox, N.P. Hammond, J. Kay, R.P. Walker Diamond, Oxfordshire, United Kingdom R. Bartolini, T. Pulampong JAI, Oxford, United Kingdom
	Many synchrotron radiation facilities are studying lattice upgrades in order to lower the natural emittance and hence increase the radiation brightness. At Diamond we are pursuing a novel alternative, not targeting the minimum possible emittance but instead introducing additional insertion device (ID) straights and hence increasing the capacity of the facility, while still possibly achieving a more limited reduction in emittance. The new scheme involves converting some of the DBA lattice cells into a double-DBA or DDBA, with a new ID straight between the two achromats. This then allows existing or future bending magnet ports (which in Diamond are taken from near the entrance to the second dipole of the DBA lattice) to be served by a much more powerful insertion device. We present here the design concept and preliminary lattice design, and discuss the challenging magnet, vacuum and engineering issues.

MOPEA070	Operating the Diamond Light Source in Low Alpha Mode for Users	injection, lattice, factory, electron	246
	I.P.S. Martin, R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Since its first introduction in April 2009, the low alpha operational mode has been continually refined in order to best meet the needs of the user community. Initially the optics were used only to generate short x-ray pulses, for which a stable, low emittance, single bunch was requested, with the emphasis placed on increased bunch charge over shortest absolute pulse duration. More recently, the optics have been adapted to enhance the CSR gain in the THz region of the electromagnetic spectrum. In this paper we summarise the work carried out in order to meet these two demands.

MOPEA079	Improving Emittances in Existing Storage Rings by Defocusing Dipoles	dipole, emittance, quadrupole, lattice	270
	C.E. Mayes, L. Gupta, G.H. Hoffstaetter, V.O. Kostroun, A.A. Mikhailichenko CLASSE, Ithaca, New York, USA
	Designs for ultimate storage rings typically employ two strategies to lower the emittances: 1) adding more bending magnets, and 2) using only focusing quadrupole magnets, with additional defocusing in the bending magnets. In an existing storage ring, the first strategy is precluded because the number of bends is typically fixed, but the second strategy could be used at modest expense. With the CESR storage ring as an example, we show how this is possible and propose an optics that reduces its emittance by more than a factor of 20. Furthermore, such an upgrade would could be installed incrementally without any long dark-time period.

MOPFI054	Upgrades for the CERN PSB-TO-PS Transfer at 2 GeV	injection, emittance, kicker, quadrupole	404
	W. Bartmann, J. Borburgh, J.R.T. Cole, S.S. Gilardoni, B. Goddard, O. Hans, M. Hourican, L. Sermeus, R. Steerenberg CERN, Geneva, Switzerland C.H. Yu IHEP, Beijing, People's Republic of China
	The CERN PS Booster extraction energy will be upgraded from 1.4 to 2.0 GeV to alleviate the direct space charge tune shift in the PS. The focussing structure of the transfer line will be modified in order to better match the optics between the PSB and the PS. The optics of the PS at injection and, with it, of the transfer line can be adapted to reduce the continuous losses from the already injected and circulating beam bumped towards the septum. Experimental results of the optics optimisation and probing the injection kicker gap will be shown.

MOPFI055	Design Study of a 100 GeV Beam Transfer Line from the SPS for a Short Baseline Neutrino Facility	quadrupole, target, dipole, extraction	407
	W. Bartmann, B. Goddard, A. Kosmicki, M. Kowalska, F.M. Velotti CERN, Geneva, Switzerland
	A Short Baseline neutrino facility at CERN is presently under study. It is considered to extract a 100 GeV beam from the second long straight section of the SPS into the existing transfer channel TT20, which leads to the North Area experimental zone. A new transfer line would branch off the existing TT20 line around 600 m downstream of the extraction, followed by an S-shaped horizontal bending arc to direct the beam with the correct angle onto the defined target location. This paper describes the optimisation of the line geometry with respect to the switch regions in TT20, the integration into the existing facilities and the potential refurbishment of existing magnets. The optics design is shown, and the requirements for the magnets, power converters and instrumentation hardware are discussed.

MOPFI059	Design and Performance of the Beam Transfer Lines for the HIE-ISOLDE Project	target, emittance, simulation, dipole	416
	A.S. Parfenova, W. Andreazza, J. Bauche, E.D. Cantero, P. Farantatos, M.A. Fraser, B. Goddard, Y. Kadi, A.J. Kolehmainen, D. Lanaia, M. Martino, R. Mompo, E. Siesling, A.G. Sosa, M.A. Timmins, G. Vandoni, D. Voulot, E.S. Zografos CERN, Geneva, Switzerland
	Beam design and beam optics studies for the HIE-ISOLDE transfer lines have been carried out in MadX, and benchmarked against Trace3D results. Magnet field errors and alignment imperfections leading to deviations from design parameters have been treated explicitly, and the sensitivity of the machine's lattice to different individual error sources was studied. As a result, the tolerances for the various error-contributions have been specified for the different equipment systems. The design choices for the expected magnet field and power supply quality, alignment tolerances, instrument resolution and physical aperture were validated. The methodology and results of the studies are presented.

MOPFI060	Beam Transfer to LHC with the Low Gamma-transition SPS Optics	extraction, injection, quadrupole, collimation	419
	G. Vanbavinckhove, W. Bartmann, H. Bartosik, C. Bracco, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, V. Mertens, Y. Papaphilippou, J.A. Uythoven, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	A new low gamma-transition optics with a lower integer tune, was introduced in the SPS to improve beam stability at high intensity. For transferring the beam to the LHC, the extraction bumps, extraction kickers and transfer lines needed to be adapted to the new optics. In particular, the transfer lines were re-matched and re-commissioned with the new optics. The first operational results are discussed for the SPS extraction, the transfer lines and the LHC injection. A detailed comparison is presented between the old and the new optics of the trajectories, dispersion, losses and other performance aspects.

MOPME007	High Resolution Synchrotron Light Analysis at ELSA	synchrotron, diagnostics, vacuum, electron	482
	S. Zander, F. Frommberger, P. Hänisch, W. Hillert, M.T. Switka ELSA, Bonn, Germany
	Funding: Funded by the DFG within the SFB/ TR 16 The Electron Stretcher Facility ELSA provides polarized electrons with energies up to 3.5 GeV for external hadron experiments. In order to suffice the need of stored beam intensities towards 200 mA, advanced beam instability studies need to be carried out. An external diagnostic beamline for synchrotron light analysis has been set up and provides the space for multiple diagnostic tools including a streak camera with time resolution of < 1 ps. Beam profile measurements are expected to identify instabilities and reveal their thresholds. The effect of adequate countermeasures is subject to analysis. The current status of the beamline development will be presented.

MOPME065	Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object	radiation, vacuum, diagnostics, scattering	625
	A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin Saint-Petersburg State University, Russia
	Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation. Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well. A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066	Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial	radiation, vacuum, diagnostics, lattice	628
	A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev Saint-Petersburg State University, Russia
	Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation. The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches*. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch. A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011). **V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME069	Multi-OTR System for Linear Colliders	emittance, target, diagnostics, linac	637
	J. Resta-López, A. Faus-Golfe IFIC, Valencia, Spain J. Alabau-Gonzalvo, R. Apsimon, A. Latina CERN, Geneva, Switzerland
	We study the feasibility of using a multi-Optical Transition Radiation (mOTR) system for fast transverse emittance reconstruction and x-y coupling correction in the Ring to Main Linac (RTML) of the future linear colliders: ILC and CLIC. OTR monitors are mature and reliable diagnostic tools that could be very suitable for the setup and tuning of the machine in single-bunch mode. Here we study the requirements for a mOTR system adapted to the optical conditions and beam parameters of the RTML of both the ILC and CLIC.

MOPWA037	Commissioning of the CERN Linac4 BPM System with 50 MeV Proton Beams	linac, pick-up, proton, simulation	750
	J. Tan, M. Ludwig, L. Søby, M. Sordet, M. Wendt CERN, Geneva, Switzerland
	The new Linac4 at CERN will provide a 160 MeV H⁻ ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two beam pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations.

MOPWA058	Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2	cavity, feedback, quadrupole, focusing	807
	Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin JAI, Oxford, United Kingdom S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White SLAC, Menlo Park, California, USA Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

MOPWA076	Improvements to Existing Jefferson Lab Wire Scanners	emittance, diagnostics, controls, linac	855
	M.D. McCaughan, M.G. Tiefenback, D.L. Turner JLAB, Newport News, Virginia, USA
	This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

MOPWA077	EPICS, MATLAB, GigE CCD Camera Based Beam Imaging System for the IAC-RadiaBeam THz Project	EPICS, controls, GUI, background	858
	C.F. Eckman, A. Andrews, T. Downer, Y. Kim, C. O'Neill IAC, Pocatello, IDAHO, USA P. Buaphad, Y. Kim ISU, Pocatello, Idaho, USA Y. Kim JLAB, Newport News, Virginia, USA
	At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating an L-band RF linear accelerator running at low energies (5 - 44 MeV) for the IAC-RadiaBeam THz project. We have designed and implemented an image acquisition and analysis system that can be used for real time observation of the electron beam, tuning of THz radiation production, and measurement of the transverse beam emittance. The imaging system contains an Yttrium Aluminium Garnet (YAG) screen on an actuator, a Prosilica GC1290 GigE CCD camera with an adjustable lens, a screen illuminator, an optical alignment structure, and a lead tube for the camera shielding. The real time continuous beam images can be acquired by SampleViewer, while the single shot beam image can be acquired by the Experiential Physics and Industrial Control System (EPICS) and areaDetector. In this paper, we describe components of the imaging system, the real time beam image acquisition with SampleViewer, the single shot beam image acquisition with areaDetector, and a remote controllable beam image acquisition via MATLAB Channel Access (MCA), MATLAB, and EPICS.

MOPWO019	An IDE for Spin-orbit Dynamics Simulation	simulation, lattice, controls, betatron	921
	A.N. Ivanov, N.V. Kulabukhova St. Petersburg State University, St. Petersburg, Russia
	In this paper a prototype of an IDE for simulation of spin-orbit motion is described. It is based on the component software development and provides a flexible graphic user interface. One of the main parts of it is numerical methods for ordinary differential equations integration. For numerical simulation it is possible use either the matrix map algorithm or traditional step-by-step methods. This workflow allows choosing one of numerical algorithms and to provide necessary computational experiments. It is also contains both a visual designer of an accelerator lattice and additional tools for control parameters of the model. There is also exists possibility for code generation in different programming languages and computation on high-performance systems.

MOPWO027	Improved TEAPOT Method and Tracking with Thick Quadrupoles for the LHC and its Upgrade	quadrupole, lattice, insertion, multipole	945
	H. Burkhardt, R. De Maria, M. Giovannozzi, T. Risselada CERN, Geneva, Switzerland
	The comparison between tracking with thick and thin lens models for the LHC have been studied. A widely-used method to generate thin models is based on the TEAPOT slicing, which, in the original implementation is limited in the number of slices. In this paper an improved method is presented, which overcomes some of the limitations of the original TEAPOT. The performance is analysed and the impact on numerical simulation of the dynamic aperture is evaluated, both for the LHC and its upgrade, HL-LHC.

MOPWO033	Analysis of LHC Transfer Line Trajectory Drifts	injection, extraction, simulation, dipole	960
	L.N. Drøsdal, W. Bartmann, H. Bartosik, C. Bracco, B. Goddard, V. Kain, Y. Papaphilippou, J.A. Uythoven, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	The LHC is filled from the SPS via two 3km long transfer lines. In the first years of LHC operation large trajectory variations were discovered. The sources of bunch-by-bunch and shot-by-shot trajectory variations had been identified and improved by the 2012 LHC run. The origins of the longer term drifts were however still unclear and significant time was spent correcting the trajectories. In the last part of the 2012 run the optics in the SPS was changed to lower transition energy. Trajectory stability and correction frequency will be compared between before and after the optics change in the SPS. The sources of the variations have now been identified and will be discussed in this paper. Remedies for operation after the long shutdown will be proposed.

MOPWO034	Energy Deposition Studies for the Upgrade of the LHC Injection Lines	injection, proton, quadrupole, luminosity	963
	A. Mereghetti, O. Aberle, F. Cerutti, B. Goddard, V. Kain, F.L. Maciariello, M. Meddahi CERN, Geneva, Switzerland R. Appleby UMAN, Manchester, United Kingdom E. Gianfelice-Wendt Fermilab, Batavia, USA
	The LHC Injectors Upgrade (LIU) Project aims at upgrading the systems in the LHC injection chain, to reliably deliver the beams required by the High-Luminosity LHC (HL-LHC). Given the challenging beam intensities and emittances, a review of the existing beam-intercepting devices is on-going, in order to assess heat loads and consequent thermo-mechanical stresses. Moreover, the exposure of downstream elements to induced shower radiation is assessed. The study is intended to spot possible issues and contribute to the definition of viable design and layout solutions.

MOPWO035	Layouts for Crystal Collimation Tests at the LHC	collimation, simulation, insertion, proton	966
	D. Mirarchi, S. Redaelli, W. Scandale CERN, Geneva, Switzerland D. Mirarchi The Imperial College of Science, Technology and Medicine, London, United Kingdom V. Previtali Fermilab, Batavia, USA
	Various studies have been carried out in the past years regarding crystal collimation for the LHC. A new extensive campaign of simulations was performed to determine optimum layouts for beam tests at the LHC. The layouts are determined based on semi-analytical models for the dynamics of channeled particles. Detailed SixTrack tracking with all collimators of the ring are then used to validate the different options. An overview of the ongoing studies is given. Comparative studies between the present collimation system, the crystal collimation system, and different crystal collimation layout are presented.

MOPWO042	Simulations of Collimation Cleaning Performance with HL-LHC Optics	simulation, collimation, luminosity, proton	987
	A. Marsili, R. Bruce, R. De Maria, S.D. Fartoukh, S. Redaelli CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The upgrade of the LHC from the current set-up to high luminosity performances will provide new challenges for the protection of the machine. The different optics considered might create new needs for collimation, and require new collimation locations. In order to evaluate the cleaning performances of the collimation system, different halo cleaning simulations were performed with the particle tracking code SixTrack. This paper presents the cleaning performance simulation results for the high luminosity Achromatic Telescopic Squeeze optics considered as baseline for the HL-LHC. The new limitations observed and possible solutions are discussed.

MOPWO043	Hollow Electron Lens Simulation for the SPS	electron, simulation, collimation, proton	990
	V. Previtali, G. Stancari, A. Valishev Fermilab, Batavia, USA S. Redaelli CERN, Geneva, Switzerland
	Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No. DE-AC02-07CH11359 with the United States Dep. of Energy. This work was supported by the US LHC Accelerator Research Program (LARP). The hardware of the Tevatron hollow electron lens, which has been used in the past for collimation purposes, is presently available. Possible applications of similar devices in the LHC are under evaluation, but a realistic date for installation of electron lenses in the LHC would be not earlier than the machine shutdown scheduled for 2018. We investigated the possibility of beam tests with the available hardware in the meantime in the SPS. This article aims to answer this question by presenting the results of dedicated numerical simulations.

MOPWO047	Studies of Thermal Loads on Collimators for HL-LHC Optics in case of Fast Losses	proton, luminosity, kicker, collimation	999
	L. Lari, R. Bruce, F. Cerutti CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The new layouts for the HL-LHC pose new challenges in terms of proton loads on the collimators around the ring, in particular for the ones of in experimental regions that become critical with squeeze optics. New layouts are under consideration, which foresee updated collimation schemes. Simulations of halo loads for in case of fast failures have been setup with SixTrack in order to determine beam loss distributions for realistic error scenarios. The particle tracking studies might then be interfaced to tools like FLUKA to evaluate the thermal loads on collimators in case of failures. In this paper, the preliminary studies performed for the baseline HL-LHC optics layouts are presented.

MOPWO059	Development of MATLAB-based Application Programs for the Optics Matching, Beam Steering, and Injection Conditioning in TPS Commissioning	linac, injection, lattice, electron	1025
	M.-S. Chiu, H.-P. Chang, P.J. Chou, F.H. Tseng NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a third generation 3GeV synchrotron light source. Its first beam commissioning is scheduled in 2014. Intensive efforts are devoted to achieve efficient transportation of the first beam from the LINAC, passing through the LTB transfer line, and its injection into the booster ring. After the beam energy has been ramped up to 3GeV in booster, the beam is extracted to the BTS transfer line. At the end of BTS, the beam is injected into the storage ring and circulates around the storage ring. In order to achieve efficient beam transportation, we have developed various MATLAB-based commissioning tools for the optics matching of transfer lines, beam steering and injection conditioning of booster and storage ring.

MOPWO063	LHeC IR Optics Design Integrated into the HL-LHC Lattice	quadrupole, proton, dipole, radiation	1034
	M. Korostelev, D. Newton, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom O.S. Brüning, R. Tomás CERN, Geneva, Switzerland E. Cruz Alaniz, D. Newton, A. Wolski The University of Liverpool, Liverpool, United Kingdom
	The two main drivers for the CDR LHeC IR design were chromaticy and synchrotron radiation. Recently it has been proposed that the LHeC IR proton optics could be integrated into the ATS scheme, which benefits from higher arc beta functions for the correction of chromaticity. In this scenario the distance between the IP and the protron triplet can be increased allowing for a reduction of the IR dipole field and the synchrotron radiation. First feasibility considerations and more in depth studies of the synchrotron radiation effects are presented in this paper.

TUXB201	Short-pulse Operation of Storage Ring Light Sources	radiation, storage-ring, electron, photon	1129
	A.-S. Müller KIT, Karlsruhe, Germany
	Short-pulse operation of synchrotron light source storage rings can be useful for both the production of IR and THz-band radiation and high repetition rate pump-probe science in the X-ray regime. Different approaches to short-pulse generation include low-alpha optics configurations, two-frequency RF potential manipulation, laser-induced femtoslicing, longitudinal crab-cavity deflection and pseudo-bunch operation with a fast kicker to isolate a single bunch. This talk should review each of these techniques and discuss implications for machine operation in terms of pulse length, beam intensity, beam stability, pulse repetition rate, output radiation beam quality and potential applications.
	Slides TUXB201 [12.058 MB]

TUPEA085	Optics Tuning and Compensation in LCLS-II	quadrupole, undulator, focusing, lattice	1313
	Y. Nosochkov, T.O. Raubenheimer, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Work supported by the US Department of Energy contract DE-AC02-76SF00515. The LCLS-II is a future upgrade of the Linear Coherent Light Source (LCLS) at SLAC. It will include two new Free Electron Lasers (FELs) to generate soft and hard X-ray radiation. The 2.9 km LCLS-II lattice will include 1/3 of the SLC linac located just before the existing LCLS, the 1.2 km bypass line, the bend section, the beam separation and diagnostic regions, and the FEL undulators and dump. The LCLS operation showed that occasionally the beam phase space may be significantly mismatched due to various errors in the beamline. This requires correction to ensure good beam quality in the undulators. Similarly, the LCLS-II must have lattice correction system with a large tuning range to cancel such errors. Since the various LCLS-II regions are connected using matching sections, the latter naturally can be used for correction of the mismatched lattice functions. In addition, the large tuning capability is required to provide a wide range of focusing conditions at the FEL undulators. The compensation and tuning abilities of the LCLS-II lattice have been studied for incoming beam errors equivalent to 160% of beta beat and for a factor of 5 in the range of undulator quadrupole strengths.

TUPFI001	High Luminosity LHC Matching Section Layout vs Crab Cavity Voltage	cavity, injection, luminosity, quadrupole	1328
	B. Dalena CEA/IRFU, Gif-sur-Yvette, France A. Chancé, J. Payet CEA/DSM/IRFU, France R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland
	Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan. In the framework of the HL-LHC Upgrade project we present a new possible variant for the layout of the LHC matching section located in the high luminosity insertions. This layout is optimized to reduce the demand on the voltage of the crab cavities, while substantially improving the optics squeeze-ability, both in ATS [1] and non-ATS mode. These new layout will be described in details together with its performance figures in terms of mechanical acceptance, chromatic properties and optics flexibility. [1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI014	HLLHCV1.0: HL-LHC Layout and Optics Models for 150 mm Nb3Sn Triplets and Local Crab-cavities	quadrupole, injection, sextupole, ion	1358
	R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia M. Korostelev The University of Liverpool, Liverpool, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The paper presents the latest layout and optics models for the HL-LHC upgrade project. As an evolution from the previous version SLHCV3.1b, it integrates the new Nb3Sn triplet (140T/m, 150mm) with all the additional magnets needed to be compatible with a β^* reach of 15cm and beyond. The collision optics implements the ATS* scheme which is able to provide very low value of β^* and at the same time warrants outstanding control of the chromatic aberrations within the strength limits of the existing arc sextupole scheme of the LHC. The optics models include the injection and collision optics for proton and ion operations foreseen for the HL-LHC, with improved squeeze-ability of the existing IR2 and IR8 insertions, and all the corresponding optic transitions. An aperture model and a series of optics matched in thin lenses complete the needs for a large range of dedicated beam dynamic studies (dynamic aperture, beam-beam effects, collimation). * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI015	Study of the IR2 and IR8 Squeezeability for HL-LHC Upgrade	injection, quadrupole, insertion, luminosity	1361
	A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia R. De Maria CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The paper presents the results of the study of different optics configurations which allow to reach smaller beta functions at the IP2 and IP8 in the framework of the HL-LHC project. The variants at collision energies must be compatible with the ATS* scheme which provides small beta function at the IP1 and IP5 or provide low beta function for Alice and LHCb during ion operatations. The ones at injection must satisfy injection transfer lines and aperture constraints. The final goal is to find the overlap between the phase advances of all the configuration for IR2 and IR8 respectively, in order to mainting the LHC working point without rematching the remaining insertions. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI021	FLUKA Energy Deposition Studies for the HL-LHC	luminosity, quadrupole, radiation, shielding	1379
	L.S. Esposito, F. Cerutti, E. Todesco CERN, Geneva, Switzerland
	The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches. O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.*

TUPFI022	Power Load from Collision Debris on the LHC Point 8 Insertion Magnets Implied by the LHCb Luminosity Increase	luminosity, dipole, quadrupole, proton	1382
	L.S. Esposito, F. Cerutti, A. Lechner, A. Mereghetti, A.A. Patapenka, V. Vlachoudis CERN, Geneva, Switzerland A. Mereghetti UMAN, Manchester, United Kingdom A.A. Patapenka JIPNR-Sosny NASB, Minsk, Belarus
	LHCb is aiming to upgrade its goal peak luminosity up to a value of 2 10³³ cm^-2 s⁻¹ after LS2. We investigate the collision debris impact on the machine elements by extensive FLUKA simulations, showing that the present machine layout is substantially compatible with such a luminosity goal. In particular the installation of a TAS (Target Absorber ofSecondaries, installed in front of the final focus Q1-Q3 quadrupole triplet in the LHC high luminosity insertions) turns out not to be necessary on the basis of the expected peak power deposition in the Q1 superconducting coils. A warm protection may be desirable to further reduce heat load and dose on the D2 recombination dipole, due to the absence of the TAN (Target Absorber of Neutrals, present in Point 1 and 5).

TUPFI023	Optics Design and Lattice Optimisation for the HL-LHC	luminosity, quadrupole, lattice, cavity	1385
	B.J. Holzer, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson UMAN, Manchester, United Kingdom A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia A. Chancé CEA, Gif-sur-Yvette, France B. Dalena CEA/IRFU, Gif-sur-Yvette, France A. Faus-Golfe, J. Resta IFIC, Valencia, Spain K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom C. Milardi INFN/LNF, Frascati (Roma), Italy J. Payet CEA/DSM/IRFU, France A. Wolski The University of Liverpool, Liverpool, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Cap. Spec. Progr, Grant Agreement 284404. The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach smallest beam sizes at the collision points. Depending on the available magnet technology (Nb3Sn or NbTi) a number of beam optics has been developed to define the specifications for the new super conducting quadrupoles. In the context of the optics matching new issues have been addressed and new concepts have been used: Quadrupole strength flexibility and chromatic corrections have been studied, as well as the influence of quadrupole fringe fields. The lattice has been optimised including the needs of the foreseen crab cavities and the transition between injection and low β optics had to guarantee smooth gradient changes over a wide range of β* values. Tolerances on misalignments and power converter ripple have been re-evaluated. Finally the combination of the quadrupole strengths in the high luminosity matching sections with those in the neighboring sectors is explained, a key concept of the ATS to reach smallest β* values. This paper presents the results obtained within the HiLumi collaboration Task 2.2 and summarises the main parameters of the project.

TUPFI024	Influence of the Ats Optics on Intra-Beam Scattering for HL-LHC	luminosity, emittance, simulation, collider	1388
	M. Schaumann, R. Bruce, J.M. Jowett CERN, Geneva, Switzerland M. Schaumann RWTH, Aachen, Germany
	In the future High Luminosity (HL-)LHC the influence of intra-beam scattering (IBS) will be stronger than in the present LHC, because of higher bunch intensity, small emittance and new optics. The new ATS-optics scheme modifies the lattice in the arcs around the main interaction points (IP) to provide β* values as small as 0.15m in the IP, however those modifications affect the IBS growth rates. In this paper proton IBS emittance growth rates are calculated with MADX and the Collider Time Evolution (CTE) program for two ATS-optics versions, different settings of the crossing angles and required corrections and various beam conditions at injection (450 GeV) and collision (7 TeV) energy. CTE simulations of the expected luminosity, intensity, emittance and bunch length evolution during fills are also presented

TUPFI029	Luminosity Lifetime at the LHC in 2012 Proton Physics Operation	luminosity, emittance, target, proton	1403
	M. Hostettler, G. Papotti CERN, Geneva, Switzerland
	In 2012, the LHC was operated at 4 TeV flat top energy with beam parameters that allowed exceeding a peak instantaneous luminosity of 7500 (ub*s)^-1 and a total of 23 fb^-1 integrated luminosity in the ATLAS and CMS experiments. This paper elaborates on the evolution of the LHC luminosity and luminosity lifetime during proton physics fills and through the year 2012. Bunch to bunch differences and the impact of different machine settings are highlighted.

TUPFI030	LHC Machine Developments in 2011-12	luminosity, collimation, ion, octupole	1406
	G. Papotti, R.W. Aßmann, F. Zimmermann CERN, Geneva, Switzerland
	In 2011 and 2012 LHC machine development (MD) sessions were performed during dedicated slots of beam time. These MD studies were scheduled and planned well in advance. Study topics reflected the previously agreed priorities, such as further optimizing machine performance, exploring beam parameters beyond design targets, assessing machine limitations, testing new concepts and machine settings, preparing future LHC running in view of the 2013/14 LHC shutdown and the re-commissioning of the LHC at nominal beam energy in 2014/15. We describe the planning, preparation, execution, review, and documentation of these LHC beam studies and highlight some key results.

TUPFI033	Colliding During the Squeeze and β* Leveling in the LHC	luminosity, impedance, collider, controls	1415
	X. Buffat EPFL, Lausanne, Switzerland W. Herr, M. Lamont, T. Pieloni, S. Redaelli, J. Wenninger CERN, Geneva, Switzerland
	While more challenging operationally, bringing the beams into collisions during the β squeeze rather than after presents some advantages. The large tune spread arising from the non-linearity of head-on beam-beam interactions can damp impedance-driven instabilities much more efficiently than external non-linearity such as octupoles presently used in operation. Moreover, colliding during the squeeze allows to level the luminosity, optimizing the pile-up in the experiments without changing the longitudinal distribution of collisions. Operational issues are discussed and experimental results from the LHC are presented.

TUPFI038	Operation of the Betatron Squeeze at the LHC	betatron, luminosity, proton, injection	1430
	S. Redaelli, X. Buffat, M. Lamont, G.J. Müller, M. Solfaroli Camillocci, R. Tomás, J. Wenninger CERN, Geneva, Switzerland G.J. Müller TU Dresden, Dresden, Germany
	The betatron squeeze is one of the most delicate operational phases at the large Hadron collider as it entails changes of optics performed at top energy, with full intensities. Appropriate software was developed to handle the squeeze, which ensured an efficient commissioning down to a β^* of 60 cm and a smooth operation. Several optics configurations could be commissioned and put in operation for physics. The operational experience of the LHC runs from 2010 until 2012 is presented and the overall performance reviewed.

TUPFI039	Optics Performance of the LHC During the 2012 Run	coupling, sextupole, quadrupole, octupole	1433
	P. Skowroński, T. Bach, M. Giovannozzi, A. Langner, Y.I. Levinsen, E.H. Maclean, T. Persson, S. Redaelli, T. Risselada, M. Solfaroli Camillocci, R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland M.J. McAteer The University of Texas at Austin, Austin, USA R. Miyamoto ESS, Lund, Sweden T. Persson Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
	During 2012 the LHC was operating at 4TeV with beta star at ATLAS and CMS interaction points of 0.6m. During dedicated machine studies the nominal LHC optics was also setup with beta star of 0.4m. A huge effort was put into the optics commissioning leading to a record low peak beta-beating of around 7%. We describe the correction procedures and discuss the measurement results.

TUPFI041	Operating the LHC Off-momentum for p-Pb Collisions	collimation, proton, quadrupole, alignment	1439
	R. Versteegen, R. Bruce, J.M. Jowett, A. Langner, Y.I. Levinsen, E.H. Maclean, M.J. McAteer, T. Persson, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli Camillocci, R. Tomás, G. Valentino, J. Wenninger CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom M.J. McAteer The University of Texas at Austin, Austin, USA T. Persson Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden G. Valentino University of Malta, Information and Communication Technology, Msida, Malta S.M. White BNL, Upton, Long Island, New York, USA
	The first high-luminosity p-Pb run at the LHC took place in January-February 2013 at an energy of 4 Z TeV per beam. The RF frequency difference of proton and Pb is about 60 Hz for equal magnetic rigidities, which means that beams move slightly to off-momentum, non-central, orbits during physics when frequencies are locked together. The resulting optical perturbations ("beta-beating") restrict the available aperture and required a special correction. This was also the first operation of the LHC with low beta in all four experiments and required a specific collimation set up. Predictions from offline calculations of beta-beating correction are compared with measurements during the optics commissioning and collimator set up.

TUPFI043	Matching Antisymmetric Arc Optics to Symmetric Interaction Region	quadrupole, collider, focusing, hadron	1445
	J.L. Abelleira, F. Zimmermann CERN, Geneva, Switzerland J.L. Abelleira EPFL, Lausanne, Switzerland
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579. Considering a generic double-ring collider, we discuss the matching from an antisymmetric optics in the arcs to a symmetric optics in the interaction region (IR) by means of an antisymmetric matching section (MS). As an example, we present an application to the LHC, for which a symmetric IR with extremely flat beams is under study.

TUPFI044	LHC Optics with Crab-waist Collisions and Local Chromatic Correction	sextupole, luminosity, quadrupole, dipole	1448
	J.L. Abelleira, S. Russenschuck, F. Zimmermann CERN, Geneva, Switzerland C. Milardi, M. Zobov INFN/LNF, Frascati (Roma), Italy
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579. We report the status of the optics design for a local chromatic correction with extremely-flat beams at the LHC. Together with a Large Piwinski angle, this optics opens up the possibility of crab-waist collisions at the LHC, for which a new layout of the LHC insertion region (IR) is needed. We present a complete optics and discuss the parameters of the final "double-half" quadrupole.

TUPFI049	Studies of 10 GeV Decay Ring Design for the International Design Study of the Neutrino Factory	insertion, injection, kicker, storage-ring	1457
	D.J. Kelliher, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom N. Bliss, N.A. Collomb STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Kurup, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom H. Witte BNL, Upton, Long Island, New York, USA
	Due to the discovery of large θ13 the final muon storage energy in the baseline solution of International Design Study for the Neutrino Factory (IDS-NF) has been set at 10 GeV. A new racetrack design has been produced for the decay ring to meet this requirement. The details of lattice design and the beam dynamics calculations are discussed. The feasibility of the injection system for both positive and negative muons into the ring is explored in details.

TUPFI051	Optics Transition between Injection and Collision Optics for the HL-LHC Upgrade Project	quadrupole, injection, insertion, luminosity	1460
	M. Korostelev, A. Wolski The University of Liverpool, Liverpool, United Kingdom R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland M. Korostelev, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. Plans for the luminosity upgrade of the LHC collider at CERN (HL-LHC) are based on implementation of magnets with larger apertures in the interaction regions, together with the ATS [] technique to reach very low values of the beta function at the collision points. The transition from injection to collision optics will be carried out in two stages, and will involve varying the strengths of the quadrupoles within the straight sections. Solutions for the optics transition have to meet a variety of challenging constraints, including constraints on the phase advances and Twiss parameters throughout the straights involved in the transition, specified minimum and maximum strengths of the quadrupoles, etc. Moreover, to minimize the time taken for the transition, the variation of the quadrupole strengths should be as smooth as possible, especially for the strongest quadrupoles. Avoiding changes of slope as much as possible will also minimize hysteresis effects in the super-conducting matching quadrupoles participating to the process. This paper presents one possible solution for the optics transition, calculated for the HLLHCv1.0 version of the optics and layout of the HL-LHC. S. Fartoukh, "An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade", in proceedings of IPAC11, p. 2088.

TUPFI079	A Proposed “Delay Line” for Hadron Beams in RHIC	dipole, quadrupole, hadron, interaction-region	1532
	N. Tsoupas, V. Litvinenko, V. Ptitsyn, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A “delay line” has been proposed to be installed in the Blue ring of the RHIC to accommodate collisions of asymmetric nuclei. The delay line can also be used in the e-RHIC accelerator to accommodate electron hadron collisions at various energies. We will present the layout and the optics of the delay line and we will discuss the energy range that asymmetric collisions can be performed in the RHIC collider.

TUPME012	Space Charge Simulation based on a Measured Optics in J-PARC MR	space-charge, resonance, sextupole, coupling	1589
	K. Ohmi, S. Igarashi, Y. Sato, J. Takano KEK, Ibaraki, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	Linear optics parameters, beta, alpha, phase, x-y coupling and dispersion are measured by phase space monitor and/or other tools. Nonlinear effects due to the space charge and magnets are dominantly determined by linear optics. For example, the beam distribution is mainly determined by linear optics, and error of beta function at a sextuple magnet is larger than error of magnet strength generally. This means space charge simulation based on the measured optics takes into account of the major part of errors. We discuss how beam loss degrade and which resonances are induced by the errors in the simulations.

TUPME024	Re-optimization of the Final Focus System Optics with Vertical Chromatic Correction	sextupole, luminosity, linear-collider, collider	1622
	Y. Wang, J. Gao IHEP, Beijing, People's Republic of China P. Bambade LAL, Orsay, France
	Funding: The France China Particle Physics Laboratory (FCPPL) and The National Natural Science Foundation of China (NSFC, Project 11175192) The purpose of the final focus (FF) system of the future linear collider (ILC and CLIC) is to demagnify the beam to the required size at the IP. This can be done in a compact way based on a local chromaticity correction. Two important issues are beam-beam induced radiation effects and the optical correction strategy to mitigate static and dynamic imperfections. For a small enough beam energy spread, we investigate the possibility to get a smaller vertical beam size, at the expense of a larger horizontal beam size, by re-optimising the final focus optics with chromatic correction mainly in the vertical plane. Firstly, we track the beam with MAD-X, with and without chromaticity correction, to estimate the optimum betax and betay values by rematching the linear optics, and cross-check and improve the rematching procedure with MAPCLASS. Then, we study the original design and an alternative simplified optical system, using a set of enlarged betax values, and optimize the sextupoles as a function of betay to minimize the vertical beam size for different assumptions on the energy spread.

TUPME030	Emittance Reconstruction from Measured Beam Sizes	emittance, coupling, simulation, FEL	1640
	J. Giner Navarro, A. Faus-Golfe, J. Fuentes, J. Navarro, J. Resta IFIC, Valencia, Spain
	In this paper we analyze the projected emittance (2D) and the intrinsic emittance (4D) reconstruction method by using the beam size measurements at different locations. We have studied analytically the conditions of solvability of the systems of equations involved in this process and we have obtained some rules about the locations of the measurement stations to avoid unphysical results. Presently, simulations are being made to test the robustness of the algorithm in realistic scenarios with high coupling and measurement errors. The special case of a multi-OTR system in ATF2 is being studied in much detail. The results of these studies will be very useful to better determine the location of the emittance measurement stations in the diagnostic sections of Future Linear Colliders.

TUPME034	Experimental Studies for Future LHC Beams in the SPS	emittance, injection, brightness, space-charge	1652
	H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour-Cave, J. Esteban Müller, W. Höfle, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko CERN, Geneva, Switzerland A.Y. Molodozhentsev KEK, Ibaraki, Japan
	The High Luminosity LHC (HL-LHC) project requires significantly higher beam intensity than presently accessible in the LHC injector chain. The aim of the LHC injectors upgrade project (LIU) is to prepare the CERN accelerators for the future needs of the LHC. Therefore a series of machine studies with high brightness beams were performed, assessing the present performance reach and identifying remaining limitations. Of particular concern are beam loading and longitudinal instabilities at high energy, space charge for beams with 50ns bunch spacing and electron cloud effects for beams with 25ns bunch spacing. This paper provides a summary of the performed studies, that have been possible thanks to the implementation of the SPS low gamma-transition optics.

TUPME042	The SPS as an Ultra-low Emittance Damping Ring Test Facility for CLIC	damping, emittance, wiggler, target	1661
	Y. Papaphilippou, R. Corsini, L.R. Evans CERN, Geneva, Switzerland
	In view of the plans for a future electron/positron linear collider based on the CLIC technology, an ultra-low emittance damping ring test facility is proposed, using the CERN SPS. Optics modification, required wiggler length and characteristics, energy and RF parameters are presented in order to reach CLIC performance requirements, including the effect of Intrabeam Scattering. Considerations about the necessary injected beam characteristics, its production and transfer through the existing CERN accelerator complex are also discussed.

TUPME046	Performance of SPS Low Transition Energy Optics for LHC Ion Beams	ion, emittance, scattering, space-charge	1667
	F. Antoniou, G. Arduini, H. Bartosik, T. Bohl, S. Cettour Cave, K. Cornelis, D. Manglunki, Y. Papaphilippou CERN, Geneva, Switzerland
	An optics with low transition energy has been developed in the SPS for removing intensity limitations of the LHC proton beam and has become operational towards the second part of the 2012 LHC proton run. This optics was also used for filling the LHC with lead ions during the p/Pb run of the beginning of 2013. The impact of this optics in the performance of the LHC ion beam is studied here, especially with respect to collective effects, at the SPS injection energy. In particular, the potential gain of the increased beam sizes provided by this optics, with respect to losses and emittance blow up due to space-charge and Intrabeam Scattering (IBS) is evaluated. The measured lifetime is compared with the one provided by the Touschek effect and its interplay with RF noise is studied. The models are supported by measurements in the SPS and in the LHC flat bottom.

TUPME054	Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-gradient Accelerating Structures	linac, beam-loading, beam-losses, luminosity	1691
	F. Tecker, R. Corsini, M. Dayyani Kelisani, S. Döbert, A. Grudiev, O. Kononenko, S. Lebet, J.L. Navarro Quirante, G. Riddone, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland A. Solodko JINR, Dubna, Moscow Region, Russia
	RF breakdown is a key issue for the multi-TeV high-luminosity e⁺e⁻ Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

TUPME055	Strawman Optics Design for the CERN LHeC ERL Test Facility	linac, emittance, lattice, electron	1694
	A. Valloni, O.S. Brüning, R. Calaga, E. Jensen, M. Klein, R. Tomás, F. Zimmermann CERN, Geneva, Switzerland S.A. Bogacz, D. Douglas JLAB, Newport News, Virginia, USA
	In preparation for a future Large Hadron electron Collider (LHeC) at CERN, an ERL test facility is foreseen as a test bed for SRF development, cryogenics, and advanced beam instrumentation, as well as for studies of ERL-specific beam dynamics. The CERN ERL test facility would comprise two linacs, each consisting of 4 superconducting 5-cell cavities at 802 MHz, and two return arcs on either side. With an RF voltage of 75 MeV per linac a final electron energy of about 300 MeV is reached. The average beam current should be above 6 mA to explore the parameter range of the future LHeC. In this paper we present a preliminary optics layout.

TUPWA039	Identification of the SPS Impedance at 1.4 GHz	impedance, simulation, resonance, bunching	1793
	T. Argyropoulos, T. Bohl, H. Damerau, J. Esteban Müller, E.N. Shaposhnikova, H. Timko CERN, Geneva, Switzerland
	In the SPS spectrum measurements of very long single bunches were used in the past to identify sources of longitudinal microwave instability. Shielding of the identified objects significantly improved the beam stability. However, longitudinal instabilities are still one of the limitations for high intensity LHC beams in the SPS. Recently the same measurement technique was used again, revealing a strong high frequency resonance. During the slow de-bunching with the RF switched off, the presence of different resonant impedances leads to a line density modulation at the resonant frequencies. Longitudinal profiles of bunches of various intensities were acquired. For sufficiently high intensities their spectra show a fast growing and strong modulation at 1.4 GHz. Measurements using two transverse optics with different transition energy are compared. Reproducing the measurements with numerical simulations, including the known SPS longitudinal impedances, allowed the parameter range of this unknown source to be determined. Possible candidates as impedance sources in the SPS ring are investigated.

TUPWA047	Collimator Impedance Measurements in the LHC	impedance, simulation, proton, collimation	1817
	N. Mounet, R. Bruce, E. Métral, S. Redaelli, B. Salvachua, B. Salvant, G. Valentino CERN, Geneva, Switzerland
	The collimation system of the LHC is one of the largest impedance contributors of the machine, in particular for its imaginary part. To evaluate the collimator impedance and its evolution with integrated luminosity, several measurement campaigns were performed along the year 2012, in which collimator jaws were moved back-and-forth leading to significant tune shifts for a nominal intensity bunch in the machine. These observations are compared to the results from HEADTAIL simulations with the impedance model in its current state of development.

TUPWA049	Short High-Intensity Bunches for Plasma Wakefield Experiment AWAKE in the CERN SPS	emittance, impedance, proton, plasma	1820
	H. Timko, T. Argyropoulos, H. Bartosik, T. Bohl, J. Esteban Müller, E.N. Shaposhnikova CERN, Geneva, Switzerland A.V. Petrenko BINP SB RAS, Novosibirsk, Russia
	Obtaining the shortest possible bunch length in combination with the smallest transverse emittances and highest bunch intensity – this is the wish list of the proton-bunch driven, plasma wakefield acceleration experiment AWAKE currently under feasibility study at CERN. A few measurement sessions were conducted to determine the achievable bunch properties and their reproducibility. To obtain a short bunch length, the bunches were rotated in longitudinal phase space using the maximum available RF voltage prior to extraction. Measurements were carried out in two optics with different transition energies. The main performance limitation is longitudinal beam instability that develops during the acceleration ramp. With lower transition energy, beam stability is improved, but the bucket area is smaller for the same voltage. Based on the results obtained, we shall discuss the choice of optics, the impact of longitudinal instabilities, the importance of reproducibility, as well as options for improving the bunch parameters.

TUPWO005	Survey of Beam Optics Solutions for the MLS Lattice	emittance, quadrupole, lattice, cavity	1883
	M. Ries, J. Feikes, T. Goetsch, G. Wüstefeld HZB, Berlin, Germany
	The Metrology Light Source (MLS) is an electron storage ring containing 24 quadrupole magnets which can be powered individually. Fully exploring the capabilities of the machine optics by tracking or experiment would be very time consuming. Therefore the quadrupoles were combined in five families and a numerical brute force approach was used to scan for areas of stable solutions in the scope of linear beam optics. In order to get information on the expected beam lifetimes for each generated optics, a model for the Touschek lifetime was implemented. Simulation results as well as experimental tests of selected optics will be presented.

TUPWO006	Orbit Correction System at the Collector Ring	sextupole, closed-orbit, quadrupole, dipole	1886
	A. Dolinskyy, O. Chorniy, O.E. Gorda, A.G. Kalimov, H. Leibrock, S.A. Litvinov, M. Steck GSI, Darmstadt, Germany
	The CR is dedicated ring for cooling of hot beam coming either from the antiproton separator or SFRS. It is anticipated that the understanding and control of the beam orbits will be important for achieving low beam losses. We describe our plans for measuring and correcting the COD of the CR. The closed orbit of the CR, which is distorted due to magnets misalignments, can reduce the ring acceptance by factor of 2, if a special correction system is not applied. The system, which is developed for the CR should be periodically or manually invoked to correct the global closed orbit and used to adjust the orbit position at some point using local bump. BPM and corrector magnets, which are planned to be used at the CR, are described in this paper. SVD method is used to obtain the corrector strength or corrector factors in global or local orbit correction.

TUPWO011	Invariant Criterion for the Design of Multiple Beam Profile Emittance and Twiss Parameters Measurement Sections	emittance, betatron, coupling, simulation	1901
	V. Balandin, W. Decking, N. Golubeva DESY, Hamburg, Germany
	By studying errors in the reconstructed beam parameters as functions of the errors in the beam size measurements, we introduce an optimality criteria which can be used for the design and comparison of multiple beam profile emittance and Twiss parameters measurement sections and which is independent from the position of the reconstruction point.

TUPWO013	Non-linear Beam Transport Optics for a Laser Wakefield Accelerator	undulator, radiation, focusing, electron	1907
	C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner KIT, Karlsruhe, Germany O. Jäckel, M. Kaluza, M. Reuter HIJ, Jena, Germany M. Kaluza, M. Nicolai, T. Rinck, A. Sävert IOQ, Jena, Germany M. Scheer HZB, Berlin, Germany
	Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2 The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented.

TUPWO031	Double-mini-beta Optics for the SSRF Storage Ring	dynamic-aperture, storage-ring, emittance, injection	1943
	S.Q. Tian, B.C. Jiang, M.Z. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	The two long straight sections of the SSRF storage ring will be installed by dual canted in-vacuum insertion devices in the near future. In order to get high brightness and maintain good machine performance, the vertical beta function must be reduced by a triplet of quadrupole between the two source points, which is the so-called double-mini-beta optics. We have designed this kind of optics for SSRF, and the results are presented in this paper.

TUPWO033	Effects Estimation of Superconducting Wiggler in SSRF	emittance, lattice, dynamic-aperture, quadrupole	1946
	Q.L. Zhang, B.C. Jiang, S.Q. Tian, W.Z. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	Superconducting wiggler (SW) may greatly impact on the beam dynamics in a storage ring. The effects of a 4.5T SW has been studied in SSRF including impaction on the emittance and the energy spread. To keep an undegraded storage ring performance, a local achromatic lattice is considered. The combat between the damping effect of the SW and emittance growth of local achromatic lattice is the main concern of this paper. Other effects (tune shift, beta beating, dynamics aperture, etc.) with the SW are also simulated and optimized in this paper.

TUPWO047	Preliminary Results of Linear Optics From Orbit Response in the CERN PSB	quadrupole, dipole, booster, coupling	1973
	M.J. McAteer, C. Carli, B. Mikulec, R. Tomás CERN, Geneva, Switzerland M. Aiba PSI, Villigen PSI, Switzerland
	Funding: This research project is supported by a Marie Curie Early Initial Training Network Fellowship of the European Community's Seventh Framework Programme under contract number (PITN-GA-2011-289485-OPAC) Future operations for the CERN accelerator complex will require the PS Booster to deliver higher intensity beam without increasing emittances, and having an accurate knowledge of the machine’s lattice imperfections will be necessary. We present preliminary results of the analysis of orbit response measurements in the PS Booster to determine the linear optics and to identify field errors in each of the machine’s four rings.

TUPWO050	Commissioning and Operation at β^* = 1000 m in the LHC	proton, scattering, quadrupole, insertion	1982
	H. Burkhardt, T. Persson, R. Tomás, J. Wenninger CERN, Geneva, Switzerland S. Cavalier LAL, Orsay, France
	We have developed a special optics with a β^* of 1000 m for two interaction regions (IR1 and IR5) in the LHC, to produce very low divergence beams required for elastic proton-proton scattering. We describe the design, commissioning and operation of this optics in the LHC. The β^* of 1000 m was reached by de-squeezing the beams using 17 intermediate steps beyond the β^* of 90 m, which had been the previous highest β^* value reached in the LHC. The optics was measured and the beta beating globally corrected to a level of 10 per cent.

TUPWO051	Geometry and Optics of the Electrostatic ELENA Transfer Lines	extraction, quadrupole, proton, ion	1985
	G. Vanbavinckhove, W. Bartmann, F. Butin, O. Choisnet CERN, Geneva, Switzerland R.A. Baartman TRIUMF, Vancouver, Canada D. Barna, H. Yamada University of Tokyo, Tokyo, Japan
	The future ELENA ring at CERN will decelerate the AD antiproton beam further from 5.3 MeV to 100 keV kinetic energy, to increase the efficiency of antiproton trapping. At present there are four experimental areas in the AD hall which will be complemented with the installation of ELENA by additional three experiments and an additional source for commissioning. This paper describes the optimisation of the transfer line geometry, ring rotation and source position. The optics of the transfer lines and error studies to define field and alignment tolerances are shown, and the optics particularities of electrostatic elements and their optimisation highlighted.

TUPWO057	Active Shimming of Dynamic Multipoles of an APPLE II Undulator in the Diamond Storage Ring	polarization, injection, vacuum, undulator	1997
	B. Singh, R. Bartolini, R.T. Fielder, E.C. Longhi, I.P.S. Martin, S.P. Mhaskar, R.P. Walker Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Diamond plans to operate a 5 m, long period length, APPLE undulator in a long insertion straight section. Theoretical investigations showed a severe impact on machine dynamics especially when the device is operated in vertical polarization mode. The use of local optics corrections and/or lowering of beta functions were initially investigated as possible solutions but with limited success. Active shimming of dynamic multipoles, following the approach at BESSY-II, proved more effective. The optimum shiming has been devised using kick map approach. In this paper we review the theoretical analysis, the commissioning of the active shims and the undulator, and the net effect of the undulator after compensation.

TUPWO064	Online Optimization Algorithms for Accelerators and Experimental Results	injection, coupling, quadrupole, simulation	2012
	X. Huang, W.J. Corbett, J.A. Safranek, J. Wu SLAC, Menlo Park, California, USA
	Online optimization of accelerators is becoming increasingly more important as accelerator systems become more and more complex. Online accelerator optimization is generally a multi-variant nonlinear problem with considerable noise. Efficiency and robustness are critical for online applications. Therefore optimization algorithms require special considerations. In this study we evaluate the viability of several online optimization algorithms for both ring and linac machines. Numerical simulations and experimental tests are presented to investigate performance of the algorithms.

TUPWO069	Optimization of FACET Optics	sextupole, lattice, chromatic-effects, simulation	2024
	M.-H. Wang, F.-J. Decker, N. Lipkowitz, Y. Nosochkov, G.R. White, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Funding: supported by the US Department of Energy contract DE-AC02-76SF00515. The FACET accelerator facility is designed to provide short and intense e^- or e⁺ bunches with small spot size for plasma wakefield accelerator research and other experiments. It is based on the SLAC linac with a compressor chicane in sector-10, and a second compressor chicane and final focus in sector-20 (S20). Originally, the S20 chicane was designed to be compatible with an upgrade to include a second S20 chicane for simultaneous transport of e^- and e⁺ bunches. This placed additional optics constraints which lead to strong focusing in the S20 chicane. The latter increases the effects of errors causing emittance growth. Lately, it has been decided not to proceed with the upgrade option. Therefore, there is a potential for improving the optics by relaxing the constraints. In this study, we explore alternative optics designs where beta functions in the S20 chicane and final focus are reduced in order to minimize the error effects. The optics and non-linear aberrations are evaluated, and the chromatic correction is optimized for each design. Beam tracking simulations are performed using Elegant and Lucretia. The most optimal designs are identified based on these simulations.

TUPWO073	Precision Tune, Phase and Beta Function Measurement by Frequency Analysis in RHIC	dipole, betatron, kicker, booster	2027
	C. Liu, R.L. Hulsart, A. Marusic, R.J. Michnoff, M.G. Minty, P. Thieberger BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The high quality of the RHIC turn-by-turn (TbT) data obtained from the beam position monitor (BPM) system was fully exploited by using two analysis approaches. One is a time domain least square fitting technique and the other one is a frequency domain interpolated Fourier Transform technique. Both methods were applied to 1024-turn data from kicked beam and from continuous coherent excitation experiments. The betatron phase precisions obtained with both methods were ~0.1 degree for the continuous excitation and ~0.2 degree for the impulse excitation. The algorithms of these two analyses and comparison of their results will be presented in this report.

WEXB101	Optics Optimization for Reducing Collective Effects and Raising Instability Thresholds in Lepton and Hadron Rings	emittance, synchrotron, collective-effects, brightness	2033
	Y. Papaphilippou, F. Antoniou, H. Bartosik CERN, Geneva, Switzerland
	This paper covers recent progress in the design of optics solutions to minimize collective effects such as beam instabilities, intra-beam scattering or space charge in hadron and lepton rings. The necessary steps are reviewed for designing the optics of high-intensity and high-brightness synchrotrons but also ultra-low emittance lepton storage rings, whose performance is strongly dominated by collective effects. Particular emphasis is given to proposed and existing designs illustrated by simulations and beam measurements.
	Slides WEXB101 [24.511 MB]

WEOAB101	Single Particle Tracking for Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring	cavity, HOM, simulation, synchrotron	2038
	M. Ruprecht, A. Jankowiak, A. Neumann, M. Ries, G. Wüstefeld HZB, Berlin, Germany T. Weis DELTA, Dortmund, Germany
	A scheme where 1.5 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed (BESSY^VSR). This paper presents simulations of single particle beam dynamics influenced by superconducting cavities used for the strong longitudinal beam focusing. The effect of RF jitter on (very short) bunches is investigated and results are discussed. Furthermore, possible effects on beam dynamics during ramp up and ramp down of the high gradient fields in the cavities are studied. The primary goal is to reveal preliminary design specifications for RF jitter on the basis of single particle dynamics. G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries, Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring, Proceedings of IPAC2011, San Sebastián, Spain
	Slides WEOAB101 [3.955 MB]

WEOAB202	JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs	linac, electron, quadrupole, dipole	2085
	S.A. Bogacz, G.A. Krafft, V.S. Morozov, Y. Roblin JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We propose a demonstration experiment for a new concept of a ‘dogbone’ RLA with multi-pass return arcs – JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security.
	Slides WEOAB202 [1.485 MB]

WEOBB203	Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors	kicker, quadrupole, pick-up, target	2097
	P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts CERN, Geneva, Switzerland P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts JAI, Oxford, United Kingdom P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma), Italy E. Ikarios National Technical University of Athens, Athens, Greece
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579 The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam. We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.
	Slides WEOBB203 [6.770 MB]

WEPWA004	Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes	linac, cryomodule, injection, acceleration	2129
	Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko HZB, Berlin, Germany
	The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability.

WEPWA030	Using the Power Spectral Density Method to Characterize and Evaluate the X-ray Mirrors Surfaces	synchrotron, simulation, focusing, brilliance	2196
	W.Q. Hua, F.G. Bian, Y.M. He, W.H. Lin, L. Song, J. Wang, N. Zhao SINAP, Shanghai, People's Republic of China
	Rapid progress in synchrotron X-ray beams’ coherence and X-ray optics performance places a high demand on characterization and evaluation of optical surface figure and slope errors and roughness on meter-long optics over spatial frequencies as short as 0.1mm. In this paper, the propagation model of hard X-ray beams through reflecting mirror surface is proposed based on wave-front propagation, and numerical simulations are performed for predicting the hard X-ray focusing performance of different imperfect mirrors using a Fresnel diffraction calculation. The imperfect mirror surface height maps synthesized from power spectral functions are used to analyze and evaluate the influences of different mirror surface errors on the reflected hard X-ray beam properties.

WEPWA051	Extraction Beam Line for Light Sources	extraction, emittance, injection, kicker	2232
	M. Aiba, M. Böge, T. Garvey, N. Milas, A. Saá Hernández, A. Streun PSI, Villigen PSI, Switzerland
	Most of measurements, with circulating beam in a ring, to determine transverse and longitudinal phase space volume are rather indirect although it is of importance to characterize these beam parameters for better understanding the machine. Direct measurements may be performed when the beam is extracted to a beam line, where destructive methods are available. However, light sources can tolerate internal beam dumping and thus do not have an extraction line in general. We, therefore, propose a diagnostic dedicated extraction line, motivated by precise determination of the geometrical vertical emittance, which can be a few pm or even less and general comparisons of direct and indirect measurements. Such an extraction beam line has been realized in several accelerator facilities, e.g. KEK-ATF. The idea is, however, to equip a compact beam line, which fits into the existing tunnel and allows us to measure transverse and longitudinal emittances. We present possible design of an extraction beam line assuming typical light source parameters.

WEPEA021	Influence of the Vacuum Chamber Limitation on Dynamic Aperture Calculations	dynamic-aperture, vacuum, multipole, resonance	2543
	M. Attal SESAME, Allan, Jordan
	In a storage ring the evaluation of the dynamic aperture taking into account the vacuum chamber limitation is more accurate and may display nonlinearities that could not be seen in the conventional absolute dynamic aperture calculations. This has been investigated in this paper and demonstrated in SESAME dynamic aperture case where taking into account the vacuum chamber uncovered the seriousness of a 5th order resonance mainly when errors like high order multipoles were introduced to the lattice. The destructive effect of the 5th order resonance has been avoided by changing the fractional part of the tunes. The problem has also been more investigated using the Frequency Map Analysis technique.

WEPEA045	Specifications of the Field Quality at Injection Energy of the New Magnets for the HL-LHC Upgrade Project	injection, dynamic-aperture, multipole, simulation	2603
	R. De Maria, S.D. Fartoukh, M. Giovannozzi CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The HL-LHC project relies on new magnet designs and technologies to achieve very small β^* values. In particular, Nb3Sn magnets show large allowed multipole imperfections at low current. These field errors may have a non-negligible impact on the dynamic aperture and beam life time in the HL-LHC, also because of the smaller-than-nominal β^* values foreseen IR1 and IR5 at injection energy, which aims at decreasing the dynamic range of the squeeze and therefore contributing to optimize the turn around time. The paper describes an analysis of the machine performance based on analytical estimates and tracking simulations with the goal of providing field quality specifications for the new magnets.

WEPEA047	Dynamic Aperture Performance for Different Collision Optics Scenarios for the LHC Luminosity Upgrade	multipole, luminosity, dynamic-aperture, injection	2609
	M. Giovannozzi, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland A. Chancé, B. Dalena, J. Payet CEA/IRFU, Gif-sur-Yvette, France K.M. Hock, M. Korostelev, A. Wolski The University of Liverpool, Liverpool, United Kingdom J. Resta-López IFIC, Valencia, Spain
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The ATS[1] optics solution for the HL-LHC offers the possibility of different collision optics, with a β^* as small as 10 cm in both transverse planes, or with a β^* aspect ratio of up to 4 pushing β^* to even smaller value (5cm) in the parallel separation plane while relaxing it (20 cm) in the crossing plane. The latter configuration features two possible options for alternated orientations of the crossing plane in the two high luminosity insertions, both considered in this study. In this paper we study the impact of few selected field imperfection models of the new magnets foreseen for the upgrade through tracking simulations and scaling laws. [1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA048	Specification of a System of Correctors for the Triplets and Separation Dipoles of the LHC Upgrade	multipole, dipole, simulation, insertion	2612
	M. Giovannozzi, R. De Maria, S.D. Fartoukh CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The luminosity upgrade of the LHC aims at reducing β^* from 55 cm to 15 cm or beyond. This can be achieved by the ATS* scheme and means of new large aperture superconducting triplet (IT) quadrupoles (150 mm), preferably using the Nb3Sn technology in order to keep the gradient reasonably high (140 T/m). The field quality requires careful specification in order to ensure a large enough dynamic aperture. In this context, dedicated corrector magnets are foreseen to provide semi-local corrections of specific multipole components and find the best possible compromise between the demand and what can be realistically achieved by the magnet manufacturer. In this paper the layout and main parameters of the IT corrector package are presented together with the correction strategy. Moreover, the foreseen performance is discussed in detail. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA049	Analysis of the Non-linear Fringe Effects of Large Aperture Triplets for the HL LHC Project	quadrupole, dipole, simulation, luminosity	2615
	A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov BINP SB RAS, Novosibirsk, Russia A. Chancé, B. Dalena, J. Payet CEA/IRFU, Gif-sur-Yvette, France R. De Maria, S.D. Fartoukh, M. Giovannozzi CERN, Geneva, Switzerland
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The HL-LHC project relies on large aperture quadrupoles which are compatible with the very large beam sizes in the inner triplets resulting from the strong reduction of β^*. As a result the beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. The spatial extension of these fringe fields increases as well more or less linearly with the coil aperture, which is an additional motivation to analyse this aspect in detail in the framework of the High Luminosity LHC design study. This paper will quantify this effect both by direct analytical estimates using first order Hamiltonian perturbation theory, and via numerical studies thanks to the dedicated implementation of a fringe field symplectic integrator in SixTrack.

WEPEA054	CERN PS Optical Properties Measured with Turn-by-turn Orbit Data	resonance, simulation, extraction, kicker	2627
	C. Hernalsteens, T. Bach, S.S. Gilardoni, M. Giovannozzi, A. Lachaize, G. Sterbini, R. Tomás, R. Wasef CERN, Geneva, Switzerland
	The performance of the PS has been constantly increasing over the years both in terms of beam parameters (intensity and brightness) and beam manipulations (transverse and longitudinal splitting). This implies a very good knowledge of the linear and non-linear model of the ring. In this paper we report on a detailed campaign of beam measurements based on turn-by-turn orbit data aimed at measuring the optics in several conditions as well as the resonance driving terms. The goal of this study is to assess whether any specific correction system should be envisaged to achieve the required future performance.

WEPEA058	LSS Layout Optimizations for Low-beta Optics for the HL-LHC	quadrupole, sextupole, luminosity, chromatic-effects	2639
	B.J. Holzer, R. De Maria CERN, Geneva, Switzerland R. Appleby, L.N.S. Thompson UMAN, Manchester, United Kingdom L.N.S. Thompson Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404 The High Luminosity LHC (HL-LHC) project aims to upgrade the existing LHC to a peak luminosity of the order 10³⁵cm^-2s⁻¹, while retaining as much of the nominal layout and hardware as possible. The current baseline for this upgrade is the use of the Achromatic Telescopic Squeeze (ATS) concept, which allows mini-Beta squeeze in IRs 1 and 5 (ATLAS and CMS respectively) far below that possible with nominal optics. However it is useful to both explore the parameter space of the ATS scheme while also attempting to push the boundaries of the nominal layout. This paper presents a study into maximising optical flexibility of the nominal LHC Long Straight Sections (LSSs) around IPs 1 and 5. This involves replacing, moving or adding magnets within the LSS to investigate feasibility of exploiting a more conventional optical scheme than the ATS scheme. In particular the option of replacing single LSS quadrupoles with doublets is explored. The study also looks at making similar changes to the LSS while also implementing the ATS scheme, to further explore the ATS parameter space with the benefit of experience gained into flexibility of a modified nominal LHC optical scheme.

WEPEA059	Study of the Impact of Fringe Fields of the Large Aperture Triplets on the Linear Optics of the HL-LHC	quadrupole, luminosity, collider, focusing	2642
	B.J. Holzer, R. De Maria, S. Russenschuck CERN, Geneva, Switzerland R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson UMAN, Manchester, United Kingdom L.N.S. Thompson Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404 High-luminosity hadron colliders such as the High Luminosity LHC (HL-LHC) project place demanding requirements on existing and new magnet technology. The very low β^* achieved by the Achromatic Telescopic Squeeze (ATS) optics scheme* for the HL-LHC in particular, requires large apertures in the high gradient Nb3Sn final focusing inner triplet triplet. Such magnets have extended fringe fields which perturb the linear and non-linear optics. This paper presents results of studies into the liner optics of the LHC using a range of fringe field models, including measurements of fringe fields from prototype magnets, and presents calculations of the beta-beating in the machine. Furthermore a similar study is presented on the nominal LHC optics, which uses final focus quadrupoles of higher gradient but significantly smaller aperture. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA067	Beam Optics Measurements through Turn by turn Beam Position Data in the SLS	betatron, storage-ring, luminosity, positron	2663
	P. Zisopoulos, Y. Papaphilippou CERN, Geneva, Switzerland A. Streun PSI, Villigen PSI, Switzerland V.G. Ziemann Uppsala University, Uppsala, Sweden
	Refined Fourier analysis of turn-by-turn (TBT) transverse position data measurements can be used for determining several beam properties of a ring, such as transverse tunes, optics functions, phases, chromatic properties and coupling. In particular, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm is used to analyze TBT data from the Swiss Light Source (SLS) storage ring in order to estimate on and off-momentum beam characteristics. Of particular interest is the potential of using the full position information within one turn in order to measure beam optics properties.

WEPEA082	AGS Model in Zgoubi. RHIC Run 13 Polarization Modeling. Status.	simulation, polarization, extraction, injection	2699
	F. Méot, L. A. Ahrens, K.A. Brown, Y. Dutheil, J.W. Glenn, C.E. Harper, H. Huang, V.H. Ranjbar, T. Roser, V. Schoefer, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. This paper gives a status of the AGS model in the ray-tracing code Zgoubi and its operation via the ‘‘AgsZgoubiModel'' and the ‘‘AgsModelViewer'' applications available from the controls system application launcher, ‘‘StartUp''. Examples of typical uses and studies performed using these are included, as optics controls, spin matching to RHIC, etc. A companion paper (MOPWA085) gives additional details, regarding especially spin dynamics and polarization studies aimed at determining optimal AGS settings for polarization during RHIC Run 13. This work is an additional step towards further combination with the already existing RHIC spin tracking model in Zgoubi, and AGS's Booster model in Zgoubi, a promising suite for detailed beam and spin dynamics studies and optimizations.

WEPME003	Determination of Optics Transfer between the Kicker and BPMs for Transverse Feedback System	kicker, feedback, betatron, synchrotron	2923
	M. Alhumaidi, A.M. Zoubir TU Darmstadt, Darmstadt, Germany J. Grieser TU Darmstadt, RTR, Darmstadt, Germany
	The knowledge of the transfer optics between the positions of the Kicker and the BPMs is required for the calculation of the correction signal in transverse feedback systems. Therefore, using nominal values of the transfer optics with uncertainties leads to feedback quality degradation, and thus beam disturbances. In this work, we propose a method for measuring the phase advances and amplitude scaling between the positions of the kicker and the BPMs. Directly after applying a kick on the beam by means of the kicker, we record the BPM signals. Consequently, we use the Second-Order Blind Identification (SOBI) algorithm to decompose the noised recorded signals into independent sources mixture. Finally, we determine the required optics parameters by identifying and analyzing the betatron oscillation sourced from the kick based on its mixing and temporal patterns. Results for the heavy ions synchrotron SIS 18 at the GSI are shown.

WEPME055	Investigation of Source Point Instabilities in Dipole Magnet Based Beamlines	dipole, synchrotron, feedback, radiation	3055
	M. Apollonio, R. Bartolini Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	At Diamond the source point in the second dipole of the Double Bend Achromats can vary due the lack of adjacent BPMs constraining angle and position of the electron beam at the dipole. We have implemented a code based on our AT model to predict the effects of a corrector strength change and compared our predictions to data both from a beamline and from our pinhole cameras. We discuss the possibility of interfacing the code to a ray tracing routine in order to infer beam spot changes in the downstream beamline and suggest a procedure to restore the original source point.

THPEA046	Machine Protection at the LHC - Experience of Three Years Running and Outlook for Operation at Nominal Energy	injection, feedback, synchrotron, extraction	3246
	D. Wollmann, R. Schmidt, J. Wenninger, M. Zerlauth CERN, Geneva, Switzerland
	With above 22fb-1 integrated luminosity delivered to the experiments ATLAS and CMS the LHC surpassed the results of 2011 by more than a factor 5. This was achieved at 4TeV, with intensities of ~2e14p per beam. The uncontrolled loss of only a small fraction of the stored beam is sufficient to damage parts of the sc. magnet system, accelerator equipment or the particle physics experiments. To protect against this a correct functioning of the complex LHC machine protection (MP) systems through the operational cycle is essential. Operating with up to 140MJ stored beam energy was only possible due to the experience and confidence gained in the two previous running periods, where the intensity was slowly increased. In this paper the 2012 performance of the MP systems is discussed. The strategy applied for a fast, but safe, intensity ramp up and the monitoring of the MP systems during stable running periods are presented. Weaknesses in the reliability of the MP systems, set-up procedures and setting adjustments for machine development periods, discovered in 2012, are critically reviewed and improvements for the LHC operation after the up-coming long shut-down of the LHC are proposed.

THPWA004	The HIT Gantry: From Commissioning to Operation	ion, proton, dipole, diagnostics	3636
	M. Galonska, S. Brons, R. Cee, Th. Haberer, K. Höppner, J.M. Mosthaf, A. Peters, S. Scheloske, T. Winkelmann HIT, Heidelberg, Germany
	The patient treatment at the first 360° raster scanning heavy ion gantry of the Heidelberg Ion Therapy Facility (HIT) started in October 2012 using proton and carbon ion beams. HIT is the first dedicated proton and carbon cancer therapy facility in Europe. It uses full 3D intensity controlled raster scanning dose delivering method of pencil beams. The ion energy ranges from ~50 up to 430 MeV/u (ion penetration depths of 20 to 300 mm in water). Beams are provided by a linac-synchrotron-system to four high energy beam lines: 2 horizontal patient treatment rooms; 1 horizontal experimental cave for quality assurance, development, and research work; and the heavy ion gantry. From the first commissioning the libraries of carbon and proton pencil beams at the gantry had been offered with the whole variety of ion beam properties: 255 energy steps, 4 beam foci, 360°, and 10 intensities (10⁶-10¹⁰/spill) regarding the central beam. This paper reflects the impact of the subsequent preclinical testing including beam size/position, and dose measurements within the irradiation field of 20x20 cm² on the further improvement of the ion optical settings of the gantry high energy transfer line.

THPWO046	The Preparation for the Commissioning of CSNS Accelerators	injection, DTL, linac, target	3872
	S. Wang, S. Fu, H.F. Ouyang, J. Peng IHEP, Beijing, People's Republic of China
	The China Spallation Neutron Source (CSNS) is now under construction, and the beam commissioning of ion source will start from the end of 2013, and will last several years for whole accelerators. The commissioning plan for the CSNS accelerators will be presented, including the commissioning correlated parameters, beam instrumentation in used commissioning, the goal at different commissioning stages. The development of high level application software will also be presented.

THPWO065	Optics Design and Correction of High Order Aberration of the Charge Stripper Beam Line of RAON	stripper, sextupole, ion, emittance	3906
	H.J. Kim, D. Jeon, H.J. Kim IBS, Daejeon, Republic of Korea J.G. Hwang, E.-S. Kim Kyungpook National University, Daegu, Republic of Korea
	RAON (Rare isotope Accelerator Of Newness) in Korea will be providing the 400 kW of 238U⁷⁹⁺ beam with 8 puA and 200 MeV/u. One of the critical components of this project in the SCL is the design of the charge stripper. Between the two segments of the SCL, the charge stripper strips electrons from ion beams to enhance the acceleration efficiency in the following SCL2. For high efficiency of the acceleration and high power in SCL2, the optimum energy of striped ion in solid carbon foil stripper for SCL1 was estimated by using code LISE. The thickness of the solid carbon foil is 300 ug/m2. Based on this study, the charge stripping efficiency of solid carbon stripper is ~80 %. For the charge selection from ions which produced by the solid carbon stripper, the dispersive section is required in down-stream of the foil. The designed optics for dispersive section is based on the mirror-symmetric optics to minimize the effect of high-order aberration. And the high-order aberration in designed optics was investigated and performed the correction of high-order effect using sextupole magnets.

THPWO080	Operational Performance of the LHC Proton Beams with the SPS Low Transition Energy Optics	emittance, brightness, extraction, injection	3945
	Y. Papaphilippou, G. Arduini, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, C. Bracco, S. Cettour-Cave, K. Cornelis, L.N. Drøsdal, J. Esteban Müller, B. Goddard, A. Guerrero, W. Höfle, V. Kain, G. Rumolo, B. Salvant, E.N. Shaposhnikova, H. Timko, D. Valuch, G. Vanbavinckhove, J. Wenninger CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, USA
	An optics in the SPS with lower integer tunes (20 versus 26) was proposed and introduced in machine studies since 2010, as a measure for increasing transverse and longitudinal instability thresholds, especially at low energy, for the LHC proton beams. After two years of machine studies and careful optimisation, the new “Q20” optics became operational in September 2012 and steadily delivered beam to the LHC until the end of the run. This paper reviews the operational performance of the Q20 optics with respect to transverse and longitudinal beam characteristics in the SPS, enabling high brightness beams injected into the LHC. Aspects of longitudinal beam stability, transmission, high-energy orbit control and beam transfer are discussed.

THPWO081	Design Options of a High-power Proton Synchrotron for LAGUNA-LBNO	space-charge, dipole, proton, emittance	3948
	Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, I. Efthymiopoulos, R. Garoby, F. Gerigk, B. Goddard, C. Lazaridis, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg CERN, Geneva, Switzerland
	Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology beam loss control and RF considerations. Optics optimization studies are also presented including beam transfer and collimation considerations.

THPWO083	Simulation of a Beam Rotation System for the SINQ Spallation Source at PSI	target, proton, simulation, neutron	3954
	D. Reggiani, T. Reiss, M. Seidel, V. Talanov, M. Wohlmuther PSI, Villigen PSI, Switzerland
	With a nominal beam power of nearly 1 MW on target, the PSI-SINQ ranks among the world's most powerful neutron spallation sources. The proton beam transport to the SINQ target is carried out exclusively by means of linear elements. As a consequence, at the SINQ target entrance the beam presents Gaussian transverse x and y distributions with tails cut short by collimators. This leads to a highly uneven temperature distribution inside the SINQ zircaloy target, giving rise to thermal and mechanical stress. In view of a future beam intensity upgrade, the possibility of homogenizing the beam distribution by means of a fast beam rotation system is currently under study. Important aspects of this method concern the resulting neutron spectrum and flux distribution. The simulations of the beam distribution achievable thanks to this technique as well as its consequences in terms of neutron production are presented in this contribution.

THPWO092	Update of Beam Optics and SRF Cavities for Project X	linac, cavity, cryomodule, solenoid	3975
	T.N. Khabiboulline, P. Berrutti, V.A. Lebedev, A. Lunin, T.H. Nicol, J.-F. Ostiguy, T.J. Peterson, L. Ristori, A. Saini, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	The Project X staging [1] requires reconsideration of the beam optics and thus, the SRF system for the 3 GeV CW linac of the Project X. The revised beam optics is presented in the paper as well as revised cavity design for SSR2 section and a new concept of the linac segmentation. The new versions for the Project X cryo-modules for the SSR2 section, low-beta 650 MHz section and high-beta 650 MHz section are discussed. The beam extraction scheme at 1 GeV is discussed also. [1] S. Holmes, “Project X News, Strategy, Meeting Goals,” 2012 Fall Project X Collaboration Meeting, 27-28 November 2012, Fermilab.

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MOODB203

vSTORM Facility Design and Simulation

injection, target, proton, dipole

55

A. Liu, A.D. Bross, D.V. Neuffer
Fermilab, Batavia, USA
S.-Y. Lee
Indiana University, Bloomington, Indiana, USA

Funding: Fermi National Accelerator Laboratory
A facility producing neutrinos from muons that decay in a storage ring can provide an extremely well understood neutrino beam for oscillation physics and the search for sterile neutrinos. The "neutrinos from STORed Muons"(nuSTORM) facility is based on this idea. The facility includes a target station with secondary particle collection, pion transfer line, pion injection, and a ~3.8 GeV/c muon storage ring. No muon cooling or RF sub-systems are required. The injection scenario for nuSTORM avoids the use of a separate pion decay channel and fast kickers. This paper reports a detailed description of the proposed injection scheme with full G4beamline simulations. We also present progresses on possible design options for a muon racetrack decay ring.

Slides MOODB203 [14.079 MB]

MOPEA005

A Linear Beam Raster System for the European Spallation Source?

target, linac, quadrupole, beam-losses

70

H.D. Thomsen, A.I.S. Holm, S.P. Møller
ISA, Aarhus, Denmark

The European Spallation Source (ESS) will, when built, be the most intense neutron source in the world. The neutrons are generated by a high power (5 MW) proton beam impacting a rotating W spallation target. To reduce the replacement frequency of components subjected to the full beam current, i.e. the proton beam window and the target, means to introduce low peak current densities, i.e. flat transverse beam profiles, are necessary. The relatively long beam pulse duration of 2.86 ms (at 14 Hz) leaves ample time to facilitate a Lissajous-like, linear raster system that illuminates a footprint area by sweeping an only moderately enlarged LINAC beamlet. Although slightly more technically challenging, this method has many advantages over the previously envisaged beam expander system based on non-linear DC magnets. The design, specifications, performance, and benefits of the beam raster system will be described and discussed.

MOPEA007

Study of Lower Emittance Optics Using Multi-Bend-Achromat Lattice at SOLEIL

emittance, dipole, lattice, quadrupole

76

R. Nagaoka, P. Brunelle, X. Gavaldà, M. Klein, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

In the framework of a future upgrade of the SOLEIL 354 m long and 2.75 GeV storage ring, a series of lattice studies has been launched to aim at reducing by an order of magnitude the current 4 nm.rad horizontal emittance. In this exercise, the main constraint imposed is to leave all the existing 24 straight sections for insertion devices untouched. In the previous study (presented at IPAC 2012), the possibility of using superbends and exploiting their longitudinal dipole field variation was pursued in lowering the emittance, finding solutions with a horizontal emittance in the sub nanometer range. In the present study, the use of MBA (Multi-Bend-Achromat) lattice is explored, which is widely recognized today as the optimal lattice in reaching an ultra-low emittance. The study aims to clarify the adaptability of the MBA and the range of attainable emittance for the SOLEIL ring, in view particularly of the short straight sections existing in half of the original DBA cells in between the dipoles. The possibility of combining the previously obtained superbend solutions with the MBA lattice is also examined.

MOPEA012

Lifetime Studies at Metrology Light Source and ANKA

cavity, electron, scattering, septum

88

T. Goetsch, J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany
A.-S. Müller
KIT, Karlsruhe, Germany

The Metrology Light Source (MLS)*, situated in Berlin (Germany) is an electron storage ring operating from 10⁵ MeV to 630 MeV and is serving as the national primary radiation source standard from the near infrared to the vacuum ultraviolet spectral region. In its standard user mode, the lifetime is dominated by the Touschek effect. Measurements and analysis of the Touschek lifetime as a function of beam current and RF-Voltage will be presented and compared to measurements done at the ANKA electron storage ring (Karlsruhe, Germany) which operates at 0.5 to 2.5 GeV**.
* R. Klein et al., Phys. Rev. ST-AB 11, 110701 (2008)
** A.-S. Müller et al., Energy Calibration Of The ANKA Storage Ring, In Proceedings of EPAC 2004

MOPEA027

New Optics with Emittance Reduction at the SPring-8 Storage Ring

emittance, photon, injection, sextupole

133

Y. Shimosaki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, T. Nakamura, T. Nakanishi, H. Ohkuma, M. Oishi, M. Shoji, K. Soutome, S. Takano, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

The machine tuning of a new optics is in progress at the SPring-8 storage ring, in order not only to provide brilliant photons for current users but also to study a strategy of a lattice design and a tuning scenario for the upgrade project SPring-8 II. The natural emittance is reduced to 2.4 nmrad from the present value of 3.4 nmrad without any change of magnet positions. The flux density 1.3 times higher than the present was observed at the diagnostics beamline. The nominal injection efficiency of the order of 80 % has been achieved (the present: 92 %) by correcting the error of the optics function, by adjusting the strength of the injection magnets and by optimizing the sextupole magnetic fields. The beam lifetime was 13 h at 1 mA / bunch (the present: 22 h), and the momentum aperture estimated from the measurement of the Touschek lifetime was 2.3 % (the present: 2.8 %). Though these are tolerable to the user operation, further optimization of the sextupoles is ongoing. After verifying the photon beam performance at beamlines, this new optics will be applied to the user operation. The optics design and its beam performance will be presented in detail.

MOPEA045

Performance Optimization and Upgrade of the SSRF Storage Ring

storage-ring, emittance, injection, cavity

178

Z.T. Zhao, B.C. Jiang, Y.B. Leng, S.Q. Tian, L. Yin, W.Z. Zhang
SINAP, Shanghai, People's Republic of China

The SSRF storage ring achieved its design performance goal in 2008, in the following years its performance was optimized and improved, including implementing top-up operation and low emittance lattice configuration as well as other attempts like fast orbit feedback and low alpha mode. In order to meet the requirements of accommodating more beamlines and high demanding performance in its phase-II beamline project, the SSRF storage ring is being upgraded with a design based on superbend based lattice and a third harmonic RF cavity system. This paper presents the main optimization works and the upgrade design considerations on the SSRF storage ring performance.

MOPEA047

Ramping of the Solaris Storage Ring Achromat

quadrupole, dipole, sextupole, lattice

184

A.I. Wawrzyniak, C.J. Bocchetta, D. Einfeld, R. Nietubyć
Solaris, Kraków, Poland
D. Einfeld
MAX-lab, Lund, Sweden
R. Nietubyć
NCBJ, Świerk/Otwock, Poland

Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program:POIG.02.01.00-12-213/09,
The combined function magnets implemented for the MAX IV and Solaris 1.5 GeV storage ring double bend achromats (DBAs) represents a challenging task in magnetic design. The constituent magnets in the DBA block may be sensitive to saturation effects which must be accounted for, especially in the case of energy ramping, as is the case for Solaris and not for MAXIV, where injection will take place at a beam energy of 0.55-0.6 GeV. The magnetic field distribution was calculated as a function of energy in the range from 0.5 GeV up to 1.5 GeV for the gradient dipole and for the quadrupoles containing a sextupole component. Results show that for the dipole, which generates the strongest field, the relative change of quadrupole strength is lower than 4.10^-3. For the quadrupoles the sextupole component is within the relative range of less than 0.7.10-4. The impact on linear and non-linear optics at low energies has been accordingly studied. This is on-going studies and only preliminary results are presented in this paper.

MOPEA066

Investigation and Test of the Possibility of Reducing the Emittance of the Diamond Storage Ring

emittance, lattice, wiggler, injection

234

B. Singh, M. Apollonio, R. Bartolini, E.C. Longhi
Diamond, Oxfordshire, United Kingdom
R. Bartolini, T. Pulampong
JAI, Oxford, United Kingdom

Theoretical and experimental studies have been carried out at the Diamond Light Source to assess the possibility of reducing the emittance of the existing storage ring by means of a change to the optics. The optics solutions obtained so far using a Multi Objective Genetic Algorithm (MOGA) increase the dispersion and the horizontal beta function in the straight section. While the emittance can be reduced to 2.1 nm this optics is limited by the operation of high field superconducting wiggler devices. In this report we present details of the new optics and present results of practical tests. We also compare the theoretical emittance growth due to a wiggler in a dispersive region with test results.

MOPEA068

Novel Lattice Upgrade Studies for Diamond Light Source

lattice, vacuum, dipole, quadrupole

240

R. Bartolini, C.P. Bailey, M.P. Cox, N.P. Hammond, J. Kay, R.P. Walker
Diamond, Oxfordshire, United Kingdom
R. Bartolini, T. Pulampong
JAI, Oxford, United Kingdom

Many synchrotron radiation facilities are studying lattice upgrades in order to lower the natural emittance and hence increase the radiation brightness. At Diamond we are pursuing a novel alternative, not targeting the minimum possible emittance but instead introducing additional insertion device (ID) straights and hence increasing the capacity of the facility, while still possibly achieving a more limited reduction in emittance. The new scheme involves converting some of the DBA lattice cells into a double-DBA or DDBA, with a new ID straight between the two achromats. This then allows existing or future bending magnet ports (which in Diamond are taken from near the entrance to the second dipole of the DBA lattice) to be served by a much more powerful insertion device. We present here the design concept and preliminary lattice design, and discuss the challenging magnet, vacuum and engineering issues.

MOPEA070

Operating the Diamond Light Source in Low Alpha Mode for Users

injection, lattice, factory, electron

246

I.P.S. Martin, R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Since its first introduction in April 2009, the low alpha operational mode has been continually refined in order to best meet the needs of the user community. Initially the optics were used only to generate short x-ray pulses, for which a stable, low emittance, single bunch was requested, with the emphasis placed on increased bunch charge over shortest absolute pulse duration. More recently, the optics have been adapted to enhance the CSR gain in the THz region of the electromagnetic spectrum. In this paper we summarise the work carried out in order to meet these two demands.

MOPEA079

Improving Emittances in Existing Storage Rings by Defocusing Dipoles

dipole, emittance, quadrupole, lattice

270

C.E. Mayes, L. Gupta, G.H. Hoffstaetter, V.O. Kostroun, A.A. Mikhailichenko
CLASSE, Ithaca, New York, USA

Designs for ultimate storage rings typically employ two strategies to lower the emittances: 1) adding more bending magnets, and 2) using only focusing quadrupole magnets, with additional defocusing in the bending magnets. In an existing storage ring, the first strategy is precluded because the number of bends is typically fixed, but the second strategy could be used at modest expense. With the CESR storage ring as an example, we show how this is possible and propose an optics that reduces its emittance by more than a factor of 20. Furthermore, such an upgrade would could be installed incrementally without any long dark-time period.

MOPFI054

Upgrades for the CERN PSB-TO-PS Transfer at 2 GeV

injection, emittance, kicker, quadrupole

404

W. Bartmann, J. Borburgh, J.R.T. Cole, S.S. Gilardoni, B. Goddard, O. Hans, M. Hourican, L. Sermeus, R. Steerenberg
CERN, Geneva, Switzerland
C.H. Yu
IHEP, Beijing, People's Republic of China

The CERN PS Booster extraction energy will be upgraded from 1.4 to 2.0 GeV to alleviate the direct space charge tune shift in the PS. The focussing structure of the transfer line will be modified in order to better match the optics between the PSB and the PS. The optics of the PS at injection and, with it, of the transfer line can be adapted to reduce the continuous losses from the already injected and circulating beam bumped towards the septum. Experimental results of the optics optimisation and probing the injection kicker gap will be shown.

MOPFI055

Design Study of a 100 GeV Beam Transfer Line from the SPS for a Short Baseline Neutrino Facility

quadrupole, target, dipole, extraction

407

W. Bartmann, B. Goddard, A. Kosmicki, M. Kowalska, F.M. Velotti
CERN, Geneva, Switzerland

A Short Baseline neutrino facility at CERN is presently under study. It is considered to extract a 100 GeV beam from the second long straight section of the SPS into the existing transfer channel TT20, which leads to the North Area experimental zone. A new transfer line would branch off the existing TT20 line around 600 m downstream of the extraction, followed by an S-shaped horizontal bending arc to direct the beam with the correct angle onto the defined target location. This paper describes the optimisation of the line geometry with respect to the switch regions in TT20, the integration into the existing facilities and the potential refurbishment of existing magnets. The optics design is shown, and the requirements for the magnets, power converters and instrumentation hardware are discussed.

MOPFI059

Design and Performance of the Beam Transfer Lines for the HIE-ISOLDE Project

target, emittance, simulation, dipole

416

A.S. Parfenova, W. Andreazza, J. Bauche, E.D. Cantero, P. Farantatos, M.A. Fraser, B. Goddard, Y. Kadi, A.J. Kolehmainen, D. Lanaia, M. Martino, R. Mompo, E. Siesling, A.G. Sosa, M.A. Timmins, G. Vandoni, D. Voulot, E.S. Zografos
CERN, Geneva, Switzerland

Beam design and beam optics studies for the HIE-ISOLDE transfer lines have been carried out in MadX, and benchmarked against Trace3D results. Magnet field errors and alignment imperfections leading to deviations from design parameters have been treated explicitly, and the sensitivity of the machine's lattice to different individual error sources was studied. As a result, the tolerances for the various error-contributions have been specified for the different equipment systems. The design choices for the expected magnet field and power supply quality, alignment tolerances, instrument resolution and physical aperture were validated. The methodology and results of the studies are presented.

MOPFI060

Beam Transfer to LHC with the Low Gamma-transition SPS Optics

extraction, injection, quadrupole, collimation

419

G. Vanbavinckhove, W. Bartmann, H. Bartosik, C. Bracco, L.N. Drøsdal, B. Goddard, V. Kain, M. Meddahi, V. Mertens, Y. Papaphilippou, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

A new low gamma-transition optics with a lower integer tune, was introduced in the SPS to improve beam stability at high intensity. For transferring the beam to the LHC, the extraction bumps, extraction kickers and transfer lines needed to be adapted to the new optics. In particular, the transfer lines were re-matched and re-commissioned with the new optics. The first operational results are discussed for the SPS extraction, the transfer lines and the LHC injection. A detailed comparison is presented between the old and the new optics of the trajectories, dispersion, losses and other performance aspects.

MOPME007

High Resolution Synchrotron Light Analysis at ELSA

synchrotron, diagnostics, vacuum, electron

482

S. Zander, F. Frommberger, P. Hänisch, W. Hillert, M.T. Switka
ELSA, Bonn, Germany

Funding: Funded by the DFG within the SFB/ TR 16
The Electron Stretcher Facility ELSA provides polarized electrons with energies up to 3.5 GeV for external hadron experiments. In order to suffice the need of stored beam intensities towards 200 mA, advanced beam instability studies need to be carried out. An external diagnostic beamline for synchrotron light analysis has been set up and provides the space for multiple diagnostic tools including a streak camera with time resolution of < 1 ps. Beam profile measurements are expected to identify instabilities and reveal their thresholds. The effect of adequate countermeasures is subject to analysis. The current status of the beamline development will be presented.

MOPME065

Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object

radiation, vacuum, diagnostics, scattering

625

A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin
Saint-Petersburg State University, Russia

Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation.
Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics*. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well.
* A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066

Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial

radiation, vacuum, diagnostics, lattice

628

A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev
Saint-Petersburg State University, Russia

Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation.
The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches**. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch.
*A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011).
**V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME069

Multi-OTR System for Linear Colliders

emittance, target, diagnostics, linac

637

J. Resta-López, A. Faus-Golfe
IFIC, Valencia, Spain
J. Alabau-Gonzalvo, R. Apsimon, A. Latina
CERN, Geneva, Switzerland

We study the feasibility of using a multi-Optical Transition Radiation (mOTR) system for fast transverse emittance reconstruction and x-y coupling correction in the Ring to Main Linac (RTML) of the future linear colliders: ILC and CLIC. OTR monitors are mature and reliable diagnostic tools that could be very suitable for the setup and tuning of the machine in single-bunch mode. Here we study the requirements for a mOTR system adapted to the optical conditions and beam parameters of the RTML of both the ILC and CLIC.

MOPWA037

Commissioning of the CERN Linac4 BPM System with 50 MeV Proton Beams

linac, pick-up, proton, simulation

750

J. Tan, M. Ludwig, L. Søby, M. Sordet, M. Wendt
CERN, Geneva, Switzerland

The new Linac4 at CERN will provide a 160 MeV H⁻ ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two beam pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations.

MOPWA058

Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2

cavity, feedback, quadrupole, focusing

807

Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin
JAI, Oxford, United Kingdom
S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
SLAC, Menlo Park, California, USA
Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

MOPWA076

Improvements to Existing Jefferson Lab Wire Scanners

emittance, diagnostics, controls, linac

855

M.D. McCaughan, M.G. Tiefenback, D.L. Turner
JLAB, Newport News, Virginia, USA

This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

MOPWA077

EPICS, MATLAB, GigE CCD Camera Based Beam Imaging System for the IAC-RadiaBeam THz Project

EPICS, controls, GUI, background

858

C.F. Eckman, A. Andrews, T. Downer, Y. Kim, C. O'Neill
IAC, Pocatello, IDAHO, USA
P. Buaphad, Y. Kim
ISU, Pocatello, Idaho, USA
Y. Kim
JLAB, Newport News, Virginia, USA

At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating an L-band RF linear accelerator running at low energies (5 - 44 MeV) for the IAC-RadiaBeam THz project. We have designed and implemented an image acquisition and analysis system that can be used for real time observation of the electron beam, tuning of THz radiation production, and measurement of the transverse beam emittance. The imaging system contains an Yttrium Aluminium Garnet (YAG) screen on an actuator, a Prosilica GC1290 GigE CCD camera with an adjustable lens, a screen illuminator, an optical alignment structure, and a lead tube for the camera shielding. The real time continuous beam images can be acquired by SampleViewer, while the single shot beam image can be acquired by the Experiential Physics and Industrial Control System (EPICS) and areaDetector. In this paper, we describe components of the imaging system, the real time beam image acquisition with SampleViewer, the single shot beam image acquisition with areaDetector, and a remote controllable beam image acquisition via MATLAB Channel Access (MCA), MATLAB, and EPICS.

MOPWO019

An IDE for Spin-orbit Dynamics Simulation

simulation, lattice, controls, betatron

921

A.N. Ivanov, N.V. Kulabukhova
St. Petersburg State University, St. Petersburg, Russia

In this paper a prototype of an IDE for simulation of spin-orbit motion is described. It is based on the component software development and provides a flexible graphic user interface. One of the main parts of it is numerical methods for ordinary differential equations integration. For numerical simulation it is possible use either the matrix map algorithm or traditional step-by-step methods. This workflow allows choosing one of numerical algorithms and to provide necessary computational experiments. It is also contains both a visual designer of an accelerator lattice and additional tools for control parameters of the model. There is also exists possibility for code generation in different programming languages and computation on high-performance systems.

MOPWO027

Improved TEAPOT Method and Tracking with Thick Quadrupoles for the LHC and its Upgrade

quadrupole, lattice, insertion, multipole

945

H. Burkhardt, R. De Maria, M. Giovannozzi, T. Risselada
CERN, Geneva, Switzerland

The comparison between tracking with thick and thin lens models for the LHC have been studied. A widely-used method to generate thin models is based on the TEAPOT slicing, which, in the original implementation is limited in the number of slices. In this paper an improved method is presented, which overcomes some of the limitations of the original TEAPOT. The performance is analysed and the impact on numerical simulation of the dynamic aperture is evaluated, both for the LHC and its upgrade, HL-LHC.

MOPWO033

Analysis of LHC Transfer Line Trajectory Drifts

injection, extraction, simulation, dipole

960

L.N. Drøsdal, W. Bartmann, H. Bartosik, C. Bracco, B. Goddard, V. Kain, Y. Papaphilippou, J.A. Uythoven, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

The LHC is filled from the SPS via two 3km long transfer lines. In the first years of LHC operation large trajectory variations were discovered. The sources of bunch-by-bunch and shot-by-shot trajectory variations had been identified and improved by the 2012 LHC run. The origins of the longer term drifts were however still unclear and significant time was spent correcting the trajectories. In the last part of the 2012 run the optics in the SPS was changed to lower transition energy. Trajectory stability and correction frequency will be compared between before and after the optics change in the SPS. The sources of the variations have now been identified and will be discussed in this paper. Remedies for operation after the long shutdown will be proposed.

MOPWO034

Energy Deposition Studies for the Upgrade of the LHC Injection Lines

injection, proton, quadrupole, luminosity

963

A. Mereghetti, O. Aberle, F. Cerutti, B. Goddard, V. Kain, F.L. Maciariello, M. Meddahi
CERN, Geneva, Switzerland
R. Appleby
UMAN, Manchester, United Kingdom
E. Gianfelice-Wendt
Fermilab, Batavia, USA

The LHC Injectors Upgrade (LIU) Project aims at upgrading the systems in the LHC injection chain, to reliably deliver the beams required by the High-Luminosity LHC (HL-LHC). Given the challenging beam intensities and emittances, a review of the existing beam-intercepting devices is on-going, in order to assess heat loads and consequent thermo-mechanical stresses. Moreover, the exposure of downstream elements to induced shower radiation is assessed. The study is intended to spot possible issues and contribute to the definition of viable design and layout solutions.

MOPWO035

Layouts for Crystal Collimation Tests at the LHC

collimation, simulation, insertion, proton

966

D. Mirarchi, S. Redaelli, W. Scandale
CERN, Geneva, Switzerland
D. Mirarchi
The Imperial College of Science, Technology and Medicine, London, United Kingdom
V. Previtali
Fermilab, Batavia, USA

Various studies have been carried out in the past years regarding crystal collimation for the LHC. A new extensive campaign of simulations was performed to determine optimum layouts for beam tests at the LHC. The layouts are determined based on semi-analytical models for the dynamics of channeled particles. Detailed SixTrack tracking with all collimators of the ring are then used to validate the different options. An overview of the ongoing studies is given. Comparative studies between the present collimation system, the crystal collimation system, and different crystal collimation layout are presented.

MOPWO042

Simulations of Collimation Cleaning Performance with HL-LHC Optics

simulation, collimation, luminosity, proton

987

A. Marsili, R. Bruce, R. De Maria, S.D. Fartoukh, S. Redaelli
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The upgrade of the LHC from the current set-up to high luminosity performances will provide new challenges for the protection of the machine. The different optics considered might create new needs for collimation, and require new collimation locations. In order to evaluate the cleaning performances of the collimation system, different halo cleaning simulations were performed with the particle tracking code SixTrack. This paper presents the cleaning performance simulation results for the high luminosity Achromatic Telescopic Squeeze optics considered as baseline for the HL-LHC. The new limitations observed and possible solutions are discussed.

MOPWO043

Hollow Electron Lens Simulation for the SPS

electron, simulation, collimation, proton

990

V. Previtali, G. Stancari, A. Valishev
Fermilab, Batavia, USA
S. Redaelli
CERN, Geneva, Switzerland

Funding: Fermilab is operated by Fermi Research Alliance, LLC, Contract No. DE-AC02-07CH11359 with the United States Dep. of Energy. This work was supported by the US LHC Accelerator Research Program (LARP).
The hardware of the Tevatron hollow electron lens, which has been used in the past for collimation purposes, is presently available. Possible applications of similar devices in the LHC are under evaluation, but a realistic date for installation of electron lenses in the LHC would be not earlier than the machine shutdown scheduled for 2018. We investigated the possibility of beam tests with the available hardware in the meantime in the SPS. This article aims to answer this question by presenting the results of dedicated numerical simulations.

MOPWO047

Studies of Thermal Loads on Collimators for HL-LHC Optics in case of Fast Losses

proton, luminosity, kicker, collimation

999

L. Lari, R. Bruce, F. Cerutti
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The new layouts for the HL-LHC pose new challenges in terms of proton loads on the collimators around the ring, in particular for the ones of in experimental regions that become critical with squeeze optics. New layouts are under consideration, which foresee updated collimation schemes. Simulations of halo loads for in case of fast failures have been setup with SixTrack in order to determine beam loss distributions for realistic error scenarios. The particle tracking studies might then be interfaced to tools like FLUKA to evaluate the thermal loads on collimators in case of failures. In this paper, the preliminary studies performed for the baseline HL-LHC optics layouts are presented.

MOPWO059

Development of MATLAB-based Application Programs for the Optics Matching, Beam Steering, and Injection Conditioning in TPS Commissioning

linac, injection, lattice, electron

1025

M.-S. Chiu, H.-P. Chang, P.J. Chou, F.H. Tseng
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) is a third generation 3GeV synchrotron light source. Its first beam commissioning is scheduled in 2014. Intensive efforts are devoted to achieve efficient transportation of the first beam from the LINAC, passing through the LTB transfer line, and its injection into the booster ring. After the beam energy has been ramped up to 3GeV in booster, the beam is extracted to the BTS transfer line. At the end of BTS, the beam is injected into the storage ring and circulates around the storage ring. In order to achieve efficient beam transportation, we have developed various MATLAB-based commissioning tools for the optics matching of transfer lines, beam steering and injection conditioning of booster and storage ring.

MOPWO063

LHeC IR Optics Design Integrated into the HL-LHC Lattice

quadrupole, proton, dipole, radiation

1034

M. Korostelev, D. Newton, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O.S. Brüning, R. Tomás
CERN, Geneva, Switzerland
E. Cruz Alaniz, D. Newton, A. Wolski
The University of Liverpool, Liverpool, United Kingdom

The two main drivers for the CDR LHeC IR design were chromaticy and synchrotron radiation. Recently it has been proposed that the LHeC IR proton optics could be integrated into the ATS scheme, which benefits from higher arc beta functions for the correction of chromaticity. In this scenario the distance between the IP and the protron triplet can be increased allowing for a reduction of the IR dipole field and the synchrotron radiation. First feasibility considerations and more in depth studies of the synchrotron radiation effects are presented in this paper.

TUXB201

Short-pulse Operation of Storage Ring Light Sources

radiation, storage-ring, electron, photon

1129

A.-S. Müller
KIT, Karlsruhe, Germany

Short-pulse operation of synchrotron light source storage rings can be useful for both the production of IR and THz-band radiation and high repetition rate pump-probe science in the X-ray regime. Different approaches to short-pulse generation include low-alpha optics configurations, two-frequency RF potential manipulation, laser-induced femtoslicing, longitudinal crab-cavity deflection and pseudo-bunch operation with a fast kicker to isolate a single bunch. This talk should review each of these techniques and discuss implications for machine operation in terms of pulse length, beam intensity, beam stability, pulse repetition rate, output radiation beam quality and potential applications.

Slides TUXB201 [12.058 MB]

TUPEA085

Optics Tuning and Compensation in LCLS-II

quadrupole, undulator, focusing, lattice

1313

Y. Nosochkov, T.O. Raubenheimer, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Work supported by the US Department of Energy contract DE-AC02-76SF00515.
The LCLS-II is a future upgrade of the Linear Coherent Light Source (LCLS) at SLAC. It will include two new Free Electron Lasers (FELs) to generate soft and hard X-ray radiation. The 2.9 km LCLS-II lattice will include 1/3 of the SLC linac located just before the existing LCLS, the 1.2 km bypass line, the bend section, the beam separation and diagnostic regions, and the FEL undulators and dump. The LCLS operation showed that occasionally the beam phase space may be significantly mismatched due to various errors in the beamline. This requires correction to ensure good beam quality in the undulators. Similarly, the LCLS-II must have lattice correction system with a large tuning range to cancel such errors. Since the various LCLS-II regions are connected using matching sections, the latter naturally can be used for correction of the mismatched lattice functions. In addition, the large tuning capability is required to provide a wide range of focusing conditions at the FEL undulators. The compensation and tuning abilities of the LCLS-II lattice have been studied for incoming beam errors equivalent to 160% of beta beat and for a factor of 5 in the range of undulator quadrupole strengths.

TUPFI001

High Luminosity LHC Matching Section Layout vs Crab Cavity Voltage

cavity, injection, luminosity, quadrupole

1328

B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
A. Chancé, J. Payet
CEA/DSM/IRFU, France
R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland

Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan.
In the framework of the HL-LHC Upgrade project we present a new possible variant for the layout of the LHC matching section located in the high luminosity insertions. This layout is optimized to reduce the demand on the voltage of the crab cavities, while substantially improving the optics squeeze-ability, both in ATS [1] and non-ATS mode. These new layout will be described in details together with its performance figures in terms of mechanical acceptance, chromatic properties and optics flexibility. [1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI014

HLLHCV1.0: HL-LHC Layout and Optics Models for 150 mm Nb3Sn Triplets and Local Crab-cavities

quadrupole, injection, sextupole, ion

1358

R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
M. Korostelev
The University of Liverpool, Liverpool, United Kingdom

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The paper presents the latest layout and optics models for the HL-LHC upgrade project. As an evolution from the previous version SLHCV3.1b, it integrates the new Nb3Sn triplet (140T/m, 150mm) with all the additional magnets needed to be compatible with a β^* reach of 15cm and beyond. The collision optics implements the ATS* scheme which is able to provide very low value of β^* and at the same time warrants outstanding control of the chromatic aberrations within the strength limits of the existing arc sextupole scheme of the LHC. The optics models include the injection and collision optics for proton and ion operations foreseen for the HL-LHC, with improved squeeze-ability of the existing IR2 and IR8 insertions, and all the corresponding optic transitions. An aperture model and a series of optics matched in thin lenses complete the needs for a large range of dedicated beam dynamic studies (dynamic aperture, beam-beam effects, collimation).
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI015

Study of the IR2 and IR8 Squeezeability for HL-LHC Upgrade

injection, quadrupole, insertion, luminosity

1361

A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
R. De Maria
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The paper presents the results of the study of different optics configurations which allow to reach smaller beta functions at the IP2 and IP8 in the framework of the HL-LHC project. The variants at collision energies must be compatible with the ATS* scheme which provides small beta function at the IP1 and IP5 or provide low beta function for Alice and LHCb during ion operatations. The ones at injection must satisfy injection transfer lines and aperture constraints. The final goal is to find the overlap between the phase advances of all the configuration for IR2 and IR8 respectively, in order to mainting the LHC working point without rematching the remaining insertions.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

TUPFI021

FLUKA Energy Deposition Studies for the HL-LHC

luminosity, quadrupole, radiation, shielding

1379

L.S. Esposito, F. Cerutti, E. Todesco
CERN, Geneva, Switzerland

The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹*. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches.
O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.

TUPFI022

Power Load from Collision Debris on the LHC Point 8 Insertion Magnets Implied by the LHCb Luminosity Increase

luminosity, dipole, quadrupole, proton

1382

L.S. Esposito, F. Cerutti, A. Lechner, A. Mereghetti, A.A. Patapenka, V. Vlachoudis
CERN, Geneva, Switzerland
A. Mereghetti
UMAN, Manchester, United Kingdom
A.A. Patapenka
JIPNR-Sosny NASB, Minsk, Belarus

LHCb is aiming to upgrade its goal peak luminosity up to a value of 2 10³³ cm^-2 s⁻¹ after LS2. We investigate the collision debris impact on the machine elements by extensive FLUKA simulations, showing that the present machine layout is substantially compatible with such a luminosity goal. In particular the installation of a TAS (Target Absorber ofSecondaries, installed in front of the final focus Q1-Q3 quadrupole triplet in the LHC high luminosity insertions) turns out not to be necessary on the basis of the expected peak power deposition in the Q1 superconducting coils. A warm protection may be desirable to further reduce heat load and dose on the D2 recombination dipole, due to the absence of the TAN (Target Absorber of Neutrals, present in Point 1 and 5).

TUPFI023

Optics Design and Lattice Optimisation for the HL-LHC

luminosity, quadrupole, lattice, cavity

1385

B.J. Holzer, R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
UMAN, Manchester, United Kingdom
A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
A. Chancé
CEA, Gif-sur-Yvette, France
B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
A. Faus-Golfe, J. Resta
IFIC, Valencia, Spain
K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C. Milardi
INFN/LNF, Frascati (Roma), Italy
J. Payet
CEA/DSM/IRFU, France
A. Wolski
The University of Liverpool, Liverpool, United Kingdom

Funding: The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Cap. Spec. Progr, Grant Agreement 284404.
The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach smallest beam sizes at the collision points. Depending on the available magnet technology (Nb3Sn or NbTi) a number of beam optics has been developed to define the specifications for the new super conducting quadrupoles. In the context of the optics matching new issues have been addressed and new concepts have been used: Quadrupole strength flexibility and chromatic corrections have been studied, as well as the influence of quadrupole fringe fields. The lattice has been optimised including the needs of the foreseen crab cavities and the transition between injection and low β optics had to guarantee smooth gradient changes over a wide range of β* values. Tolerances on misalignments and power converter ripple have been re-evaluated. Finally the combination of the quadrupole strengths in the high luminosity matching sections with those in the neighboring sectors is explained, a key concept of the ATS to reach smallest β* values. This paper presents the results obtained within the HiLumi collaboration Task 2.2 and summarises the main parameters of the project.

TUPFI024

Influence of the Ats Optics on Intra-Beam Scattering for HL-LHC

luminosity, emittance, simulation, collider

1388

M. Schaumann, R. Bruce, J.M. Jowett
CERN, Geneva, Switzerland
M. Schaumann
RWTH, Aachen, Germany

In the future High Luminosity (HL-)LHC the influence of intra-beam scattering (IBS) will be stronger than in the present LHC, because of higher bunch intensity, small emittance and new optics. The new ATS-optics scheme modifies the lattice in the arcs around the main interaction points (IP) to provide β* values as small as 0.15m in the IP, however those modifications affect the IBS growth rates. In this paper proton IBS emittance growth rates are calculated with MADX and the Collider Time Evolution (CTE) program for two ATS-optics versions, different settings of the crossing angles and required corrections and various beam conditions at injection (450 GeV) and collision (7 TeV) energy. CTE simulations of the expected luminosity, intensity, emittance and bunch length evolution during fills are also presented

TUPFI029

Luminosity Lifetime at the LHC in 2012 Proton Physics Operation

luminosity, emittance, target, proton

1403

M. Hostettler, G. Papotti
CERN, Geneva, Switzerland

In 2012, the LHC was operated at 4 TeV flat top energy with beam parameters that allowed exceeding a peak instantaneous luminosity of 7500 (ub*s)^-1 and a total of 23 fb^-1 integrated luminosity in the ATLAS and CMS experiments. This paper elaborates on the evolution of the LHC luminosity and luminosity lifetime during proton physics fills and through the year 2012. Bunch to bunch differences and the impact of different machine settings are highlighted.

TUPFI030

LHC Machine Developments in 2011-12

luminosity, collimation, ion, octupole

1406

G. Papotti, R.W. Aßmann, F. Zimmermann
CERN, Geneva, Switzerland

In 2011 and 2012 LHC machine development (MD) sessions were performed during dedicated slots of beam time. These MD studies were scheduled and planned well in advance. Study topics reflected the previously agreed priorities, such as further optimizing machine performance, exploring beam parameters beyond design targets, assessing machine limitations, testing new concepts and machine settings, preparing future LHC running in view of the 2013/14 LHC shutdown and the re-commissioning of the LHC at nominal beam energy in 2014/15. We describe the planning, preparation, execution, review, and documentation of these LHC beam studies and highlight some key results.

TUPFI033

Colliding During the Squeeze and β* Leveling in the LHC

luminosity, impedance, collider, controls

1415

X. Buffat
EPFL, Lausanne, Switzerland
W. Herr, M. Lamont, T. Pieloni, S. Redaelli, J. Wenninger
CERN, Geneva, Switzerland

While more challenging operationally, bringing the beams into collisions during the β squeeze rather than after presents some advantages. The large tune spread arising from the non-linearity of head-on beam-beam interactions can damp impedance-driven instabilities much more efficiently than external non-linearity such as octupoles presently used in operation. Moreover, colliding during the squeeze allows to level the luminosity, optimizing the pile-up in the experiments without changing the longitudinal distribution of collisions. Operational issues are discussed and experimental results from the LHC are presented.

TUPFI038

Operation of the Betatron Squeeze at the LHC

betatron, luminosity, proton, injection

1430

S. Redaelli, X. Buffat, M. Lamont, G.J. Müller, M. Solfaroli Camillocci, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland
G.J. Müller
TU Dresden, Dresden, Germany

The betatron squeeze is one of the most delicate operational phases at the large Hadron collider as it entails changes of optics performed at top energy, with full intensities. Appropriate software was developed to handle the squeeze, which ensured an efficient commissioning down to a β^* of 60 cm and a smooth operation. Several optics configurations could be commissioned and put in operation for physics. The operational experience of the LHC runs from 2010 until 2012 is presented and the overall performance reviewed.

TUPFI039

Optics Performance of the LHC During the 2012 Run

coupling, sextupole, quadrupole, octupole

1433

P. Skowroński, T. Bach, M. Giovannozzi, A. Langner, Y.I. Levinsen, E.H. Maclean, T. Persson, S. Redaelli, T. Risselada, M. Solfaroli Camillocci, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
M.J. McAteer
The University of Texas at Austin, Austin, USA
R. Miyamoto
ESS, Lund, Sweden
T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden

During 2012 the LHC was operating at 4TeV with beta star at ATLAS and CMS interaction points of 0.6m. During dedicated machine studies the nominal LHC optics was also setup with beta star of 0.4m. A huge effort was put into the optics commissioning leading to a record low peak beta-beating of around 7%. We describe the correction procedures and discuss the measurement results.

TUPFI041

Operating the LHC Off-momentum for p-Pb Collisions

collimation, proton, quadrupole, alignment

1439

R. Versteegen, R. Bruce, J.M. Jowett, A. Langner, Y.I. Levinsen, E.H. Maclean, M.J. McAteer, T. Persson, S. Redaelli, B. Salvachua, P.K. Skowroński, M. Solfaroli Camillocci, R. Tomás, G. Valentino, J. Wenninger
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom
M.J. McAteer
The University of Texas at Austin, Austin, USA
T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
G. Valentino
University of Malta, Information and Communication Technology, Msida, Malta
S.M. White
BNL, Upton, Long Island, New York, USA

The first high-luminosity p-Pb run at the LHC took place in January-February 2013 at an energy of 4 Z TeV per beam. The RF frequency difference of proton and Pb is about 60 Hz for equal magnetic rigidities, which means that beams move slightly to off-momentum, non-central, orbits during physics when frequencies are locked together. The resulting optical perturbations ("beta-beating") restrict the available aperture and required a special correction. This was also the first operation of the LHC with low beta in all four experiments and required a specific collimation set up. Predictions from offline calculations of beta-beating correction are compared with measurements during the optics commissioning and collimator set up.

TUPFI043

Matching Antisymmetric Arc Optics to Symmetric Interaction Region

quadrupole, collider, focusing, hadron

1445

J.L. Abelleira, F. Zimmermann
CERN, Geneva, Switzerland
J.L. Abelleira
EPFL, Lausanne, Switzerland

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
Considering a generic double-ring collider, we discuss the matching from an antisymmetric optics in the arcs to a symmetric optics in the interaction region (IR) by means of an antisymmetric matching section (MS). As an example, we present an application to the LHC, for which a symmetric IR with extremely flat beams is under study.

TUPFI044

LHC Optics with Crab-waist Collisions and Local Chromatic Correction

sextupole, luminosity, quadrupole, dipole

1448

J.L. Abelleira, S. Russenschuck, F. Zimmermann
CERN, Geneva, Switzerland
C. Milardi, M. Zobov
INFN/LNF, Frascati (Roma), Italy

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
We report the status of the optics design for a local chromatic correction with extremely-flat beams at the LHC. Together with a Large Piwinski angle, this optics opens up the possibility of crab-waist collisions at the LHC, for which a new layout of the LHC insertion region (IR) is needed. We present a complete optics and discuss the parameters of the final "double-half" quadrupole.

TUPFI049

Studies of 10 GeV Decay Ring Design for the International Design Study of the Neutrino Factory

insertion, injection, kicker, storage-ring

1457

D.J. Kelliher, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
N. Bliss, N.A. Collomb
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Kurup, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
H. Witte
BNL, Upton, Long Island, New York, USA

Due to the discovery of large θ13 the final muon storage energy in the baseline solution of International Design Study for the Neutrino Factory (IDS-NF) has been set at 10 GeV. A new racetrack design has been produced for the decay ring to meet this requirement. The details of lattice design and the beam dynamics calculations are discussed. The feasibility of the injection system for both positive and negative muons into the ring is explored in details.

TUPFI051

Optics Transition between Injection and Collision Optics for the HL-LHC Upgrade Project

quadrupole, injection, insertion, luminosity

1460

M. Korostelev, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
M. Korostelev, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
Plans for the luminosity upgrade of the LHC collider at CERN (HL-LHC) are based on implementation of magnets with larger apertures in the interaction regions, together with the ATS [*] technique to reach very low values of the beta function at the collision points. The transition from injection to collision optics will be carried out in two stages, and will involve varying the strengths of the quadrupoles within the straight sections. Solutions for the optics transition have to meet a variety of challenging constraints, including constraints on the phase advances and Twiss parameters throughout the straights involved in the transition, specified minimum and maximum strengths of the quadrupoles, etc. Moreover, to minimize the time taken for the transition, the variation of the quadrupole strengths should be as smooth as possible, especially for the strongest quadrupoles. Avoiding changes of slope as much as possible will also minimize hysteresis effects in the super-conducting matching quadrupoles participating to the process. This paper presents one possible solution for the optics transition, calculated for the HLLHCv1.0 version of the optics and layout of the HL-LHC.
* S. Fartoukh, "An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade", in proceedings of IPAC11, p. 2088.

TUPFI079

A Proposed “Delay Line” for Hadron Beams in RHIC

dipole, quadrupole, hadron, interaction-region

1532

N. Tsoupas, V. Litvinenko, V. Ptitsyn, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A “delay line” has been proposed to be installed in the Blue ring of the RHIC to accommodate collisions of asymmetric nuclei. The delay line can also be used in the e-RHIC accelerator to accommodate electron hadron collisions at various energies. We will present the layout and the optics of the delay line and we will discuss the energy range that asymmetric collisions can be performed in the RHIC collider.

TUPME012

Space Charge Simulation based on a Measured Optics in J-PARC MR

space-charge, resonance, sextupole, coupling

1589

K. Ohmi, S. Igarashi, Y. Sato, J. Takano
KEK, Ibaraki, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

Linear optics parameters, beta, alpha, phase, x-y coupling and dispersion are measured by phase space monitor and/or other tools. Nonlinear effects due to the space charge and magnets are dominantly determined by linear optics. For example, the beam distribution is mainly determined by linear optics, and error of beta function at a sextuple magnet is larger than error of magnet strength generally. This means space charge simulation based on the measured optics takes into account of the major part of errors. We discuss how beam loss degrade and which resonances are induced by the errors in the simulations.

TUPME024

Re-optimization of the Final Focus System Optics with Vertical Chromatic Correction

sextupole, luminosity, linear-collider, collider

1622

Y. Wang, J. Gao
IHEP, Beijing, People's Republic of China
P. Bambade
LAL, Orsay, France

Funding: The France China Particle Physics Laboratory (FCPPL) and The National Natural Science Foundation of China (NSFC, Project 11175192)
The purpose of the final focus (FF) system of the future linear collider (ILC and CLIC) is to demagnify the beam to the required size at the IP. This can be done in a compact way based on a local chromaticity correction. Two important issues are beam-beam induced radiation effects and the optical correction strategy to mitigate static and dynamic imperfections. For a small enough beam energy spread, we investigate the possibility to get a smaller vertical beam size, at the expense of a larger horizontal beam size, by re-optimising the final focus optics with chromatic correction mainly in the vertical plane. Firstly, we track the beam with MAD-X, with and without chromaticity correction, to estimate the optimum betax and betay values by rematching the linear optics, and cross-check and improve the rematching procedure with MAPCLASS. Then, we study the original design and an alternative simplified optical system, using a set of enlarged betax values, and optimize the sextupoles as a function of betay to minimize the vertical beam size for different assumptions on the energy spread.

TUPME030

Emittance Reconstruction from Measured Beam Sizes

emittance, coupling, simulation, FEL

1640

J. Giner Navarro, A. Faus-Golfe, J. Fuentes, J. Navarro, J. Resta
IFIC, Valencia, Spain

In this paper we analyze the projected emittance (2D) and the intrinsic emittance (4D) reconstruction method by using the beam size measurements at different locations. We have studied analytically the conditions of solvability of the systems of equations involved in this process and we have obtained some rules about the locations of the measurement stations to avoid unphysical results. Presently, simulations are being made to test the robustness of the algorithm in realistic scenarios with high coupling and measurement errors. The special case of a multi-OTR system in ATF2 is being studied in much detail. The results of these studies will be very useful to better determine the location of the emittance measurement stations in the diagnostic sections of Future Linear Colliders.

TUPME034

Experimental Studies for Future LHC Beams in the SPS

emittance, injection, brightness, space-charge

1652

H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour-Cave, J. Esteban Müller, W. Höfle, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko
CERN, Geneva, Switzerland
A.Y. Molodozhentsev
KEK, Ibaraki, Japan

The High Luminosity LHC (HL-LHC) project requires significantly higher beam intensity than presently accessible in the LHC injector chain. The aim of the LHC injectors upgrade project (LIU) is to prepare the CERN accelerators for the future needs of the LHC. Therefore a series of machine studies with high brightness beams were performed, assessing the present performance reach and identifying remaining limitations. Of particular concern are beam loading and longitudinal instabilities at high energy, space charge for beams with 50ns bunch spacing and electron cloud effects for beams with 25ns bunch spacing. This paper provides a summary of the performed studies, that have been possible thanks to the implementation of the SPS low gamma-transition optics.

TUPME042

The SPS as an Ultra-low Emittance Damping Ring Test Facility for CLIC

damping, emittance, wiggler, target

1661

Y. Papaphilippou, R. Corsini, L.R. Evans
CERN, Geneva, Switzerland

In view of the plans for a future electron/positron linear collider based on the CLIC technology, an ultra-low emittance damping ring test facility is proposed, using the CERN SPS. Optics modification, required wiggler length and characteristics, energy and RF parameters are presented in order to reach CLIC performance requirements, including the effect of Intrabeam Scattering. Considerations about the necessary injected beam characteristics, its production and transfer through the existing CERN accelerator complex are also discussed.

TUPME046

Performance of SPS Low Transition Energy Optics for LHC Ion Beams

ion, emittance, scattering, space-charge

1667

F. Antoniou, G. Arduini, H. Bartosik, T. Bohl, S. Cettour Cave, K. Cornelis, D. Manglunki, Y. Papaphilippou
CERN, Geneva, Switzerland

An optics with low transition energy has been developed in the SPS for removing intensity limitations of the LHC proton beam and has become operational towards the second part of the 2012 LHC proton run. This optics was also used for filling the LHC with lead ions during the p/Pb run of the beginning of 2013. The impact of this optics in the performance of the LHC ion beam is studied here, especially with respect to collective effects, at the SPS injection energy. In particular, the potential gain of the increased beam sizes provided by this optics, with respect to losses and emittance blow up due to space-charge and Intrabeam Scattering (IBS) is evaluated. The measured lifetime is compared with the one provided by the Touschek effect and its interplay with RF noise is studied. The models are supported by measurements in the SPS and in the LHC flat bottom.

TUPME054

Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-gradient Accelerating Structures

linac, beam-loading, beam-losses, luminosity

1691

F. Tecker, R. Corsini, M. Dayyani Kelisani, S. Döbert, A. Grudiev, O. Kononenko, S. Lebet, J.L. Navarro Quirante, G. Riddone, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
A. Solodko
JINR, Dubna, Moscow Region, Russia

RF breakdown is a key issue for the multi-TeV high-luminosity e⁺e⁻ Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

TUPME055

Strawman Optics Design for the CERN LHeC ERL Test Facility

linac, emittance, lattice, electron

1694

A. Valloni, O.S. Brüning, R. Calaga, E. Jensen, M. Klein, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
S.A. Bogacz, D. Douglas
JLAB, Newport News, Virginia, USA

In preparation for a future Large Hadron electron Collider (LHeC) at CERN, an ERL test facility is foreseen as a test bed for SRF development, cryogenics, and advanced beam instrumentation, as well as for studies of ERL-specific beam dynamics. The CERN ERL test facility would comprise two linacs, each consisting of 4 superconducting 5-cell cavities at 802 MHz, and two return arcs on either side. With an RF voltage of 75 MeV per linac a final electron energy of about 300 MeV is reached. The average beam current should be above 6 mA to explore the parameter range of the future LHeC. In this paper we present a preliminary optics layout.

TUPWA039

Identification of the SPS Impedance at 1.4 GHz

impedance, simulation, resonance, bunching

1793

T. Argyropoulos, T. Bohl, H. Damerau, J. Esteban Müller, E.N. Shaposhnikova, H. Timko
CERN, Geneva, Switzerland

In the SPS spectrum measurements of very long single bunches were used in the past to identify sources of longitudinal microwave instability. Shielding of the identified objects significantly improved the beam stability. However, longitudinal instabilities are still one of the limitations for high intensity LHC beams in the SPS. Recently the same measurement technique was used again, revealing a strong high frequency resonance. During the slow de-bunching with the RF switched off, the presence of different resonant impedances leads to a line density modulation at the resonant frequencies. Longitudinal profiles of bunches of various intensities were acquired. For sufficiently high intensities their spectra show a fast growing and strong modulation at 1.4 GHz. Measurements using two transverse optics with different transition energy are compared. Reproducing the measurements with numerical simulations, including the known SPS longitudinal impedances, allowed the parameter range of this unknown source to be determined. Possible candidates as impedance sources in the SPS ring are investigated.

TUPWA047

Collimator Impedance Measurements in the LHC

impedance, simulation, proton, collimation

1817

N. Mounet, R. Bruce, E. Métral, S. Redaelli, B. Salvachua, B. Salvant, G. Valentino
CERN, Geneva, Switzerland

The collimation system of the LHC is one of the largest impedance contributors of the machine, in particular for its imaginary part. To evaluate the collimator impedance and its evolution with integrated luminosity, several measurement campaigns were performed along the year 2012, in which collimator jaws were moved back-and-forth leading to significant tune shifts for a nominal intensity bunch in the machine. These observations are compared to the results from HEADTAIL simulations with the impedance model in its current state of development.

TUPWA049

Short High-Intensity Bunches for Plasma Wakefield Experiment AWAKE in the CERN SPS

emittance, impedance, proton, plasma

1820

H. Timko, T. Argyropoulos, H. Bartosik, T. Bohl, J. Esteban Müller, E.N. Shaposhnikova
CERN, Geneva, Switzerland
A.V. Petrenko
BINP SB RAS, Novosibirsk, Russia

Obtaining the shortest possible bunch length in combination with the smallest transverse emittances and highest bunch intensity – this is the wish list of the proton-bunch driven, plasma wakefield acceleration experiment AWAKE currently under feasibility study at CERN. A few measurement sessions were conducted to determine the achievable bunch properties and their reproducibility. To obtain a short bunch length, the bunches were rotated in longitudinal phase space using the maximum available RF voltage prior to extraction. Measurements were carried out in two optics with different transition energies. The main performance limitation is longitudinal beam instability that develops during the acceleration ramp. With lower transition energy, beam stability is improved, but the bucket area is smaller for the same voltage. Based on the results obtained, we shall discuss the choice of optics, the impact of longitudinal instabilities, the importance of reproducibility, as well as options for improving the bunch parameters.

TUPWO005

Survey of Beam Optics Solutions for the MLS Lattice

emittance, quadrupole, lattice, cavity

1883

M. Ries, J. Feikes, T. Goetsch, G. Wüstefeld
HZB, Berlin, Germany

The Metrology Light Source (MLS) is an electron storage ring containing 24 quadrupole magnets which can be powered individually. Fully exploring the capabilities of the machine optics by tracking or experiment would be very time consuming. Therefore the quadrupoles were combined in five families and a numerical brute force approach was used to scan for areas of stable solutions in the scope of linear beam optics. In order to get information on the expected beam lifetimes for each generated optics, a model for the Touschek lifetime was implemented. Simulation results as well as experimental tests of selected optics will be presented.

TUPWO006

Orbit Correction System at the Collector Ring

sextupole, closed-orbit, quadrupole, dipole

1886

A. Dolinskyy, O. Chorniy, O.E. Gorda, A.G. Kalimov, H. Leibrock, S.A. Litvinov, M. Steck
GSI, Darmstadt, Germany

The CR is dedicated ring for cooling of hot beam coming either from the antiproton separator or SFRS. It is anticipated that the understanding and control of the beam orbits will be important for achieving low beam losses. We describe our plans for measuring and correcting the COD of the CR. The closed orbit of the CR, which is distorted due to magnets misalignments, can reduce the ring acceptance by factor of 2, if a special correction system is not applied. The system, which is developed for the CR should be periodically or manually invoked to correct the global closed orbit and used to adjust the orbit position at some point using local bump. BPM and corrector magnets, which are planned to be used at the CR, are described in this paper. SVD method is used to obtain the corrector strength or corrector factors in global or local orbit correction.

TUPWO011

Invariant Criterion for the Design of Multiple Beam Profile Emittance and Twiss Parameters Measurement Sections

emittance, betatron, coupling, simulation

1901

V. Balandin, W. Decking, N. Golubeva
DESY, Hamburg, Germany

By studying errors in the reconstructed beam parameters as functions of the errors in the beam size measurements, we introduce an optimality criteria which can be used for the design and comparison of multiple beam profile emittance and Twiss parameters measurement sections and which is independent from the position of the reconstruction point.

TUPWO013

Non-linear Beam Transport Optics for a Laser Wakefield Accelerator

undulator, radiation, focusing, electron

1907

C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner
KIT, Karlsruhe, Germany
O. Jäckel, M. Kaluza, M. Reuter
HIJ, Jena, Germany
M. Kaluza, M. Nicolai, T. Rinck, A. Sävert
IOQ, Jena, Germany
M. Scheer
HZB, Berlin, Germany

Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2
The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented.

TUPWO031

Double-mini-beta Optics for the SSRF Storage Ring

dynamic-aperture, storage-ring, emittance, injection

1943

S.Q. Tian, B.C. Jiang, M.Z. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

The two long straight sections of the SSRF storage ring will be installed by dual canted in-vacuum insertion devices in the near future. In order to get high brightness and maintain good machine performance, the vertical beta function must be reduced by a triplet of quadrupole between the two source points, which is the so-called double-mini-beta optics. We have designed this kind of optics for SSRF, and the results are presented in this paper.

TUPWO033

Effects Estimation of Superconducting Wiggler in SSRF

emittance, lattice, dynamic-aperture, quadrupole

1946

Q.L. Zhang, B.C. Jiang, S.Q. Tian, W.Z. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

Superconducting wiggler (SW) may greatly impact on the beam dynamics in a storage ring. The effects of a 4.5T SW has been studied in SSRF including impaction on the emittance and the energy spread. To keep an undegraded storage ring performance, a local achromatic lattice is considered. The combat between the damping effect of the SW and emittance growth of local achromatic lattice is the main concern of this paper. Other effects (tune shift, beta beating, dynamics aperture, etc.) with the SW are also simulated and optimized in this paper.

TUPWO047

Preliminary Results of Linear Optics From Orbit Response in the CERN PSB

quadrupole, dipole, booster, coupling

1973

M.J. McAteer, C. Carli, B. Mikulec, R. Tomás
CERN, Geneva, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland

Funding: This research project is supported by a Marie Curie Early Initial Training Network Fellowship of the European Community's Seventh Framework Programme under contract number (PITN-GA-2011-289485-OPAC)
Future operations for the CERN accelerator complex will require the PS Booster to deliver higher intensity beam without increasing emittances, and having an accurate knowledge of the machine’s lattice imperfections will be necessary. We present preliminary results of the analysis of orbit response measurements in the PS Booster to determine the linear optics and to identify field errors in each of the machine’s four rings.

TUPWO050

Commissioning and Operation at β^* = 1000 m in the LHC

proton, scattering, quadrupole, insertion

1982

H. Burkhardt, T. Persson, R. Tomás, J. Wenninger
CERN, Geneva, Switzerland
S. Cavalier
LAL, Orsay, France

We have developed a special optics with a β^* of 1000 m for two interaction regions (IR1 and IR5) in the LHC, to produce very low divergence beams required for elastic proton-proton scattering. We describe the design, commissioning and operation of this optics in the LHC. The β^* of 1000 m was reached by de-squeezing the beams using 17 intermediate steps beyond the β^* of 90 m, which had been the previous highest β^* value reached in the LHC. The optics was measured and the beta beating globally corrected to a level of 10 per cent.

TUPWO051

Geometry and Optics of the Electrostatic ELENA Transfer Lines

extraction, quadrupole, proton, ion

1985

G. Vanbavinckhove, W. Bartmann, F. Butin, O. Choisnet
CERN, Geneva, Switzerland
R.A. Baartman
TRIUMF, Vancouver, Canada
D. Barna, H. Yamada
University of Tokyo, Tokyo, Japan

The future ELENA ring at CERN will decelerate the AD antiproton beam further from 5.3 MeV to 100 keV kinetic energy, to increase the efficiency of antiproton trapping. At present there are four experimental areas in the AD hall which will be complemented with the installation of ELENA by additional three experiments and an additional source for commissioning. This paper describes the optimisation of the transfer line geometry, ring rotation and source position. The optics of the transfer lines and error studies to define field and alignment tolerances are shown, and the optics particularities of electrostatic elements and their optimisation highlighted.

TUPWO057

Active Shimming of Dynamic Multipoles of an APPLE II Undulator in the Diamond Storage Ring

polarization, injection, vacuum, undulator

1997

B. Singh, R. Bartolini, R.T. Fielder, E.C. Longhi, I.P.S. Martin, S.P. Mhaskar, R.P. Walker
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Diamond plans to operate a 5 m, long period length, APPLE undulator in a long insertion straight section. Theoretical investigations showed a severe impact on machine dynamics especially when the device is operated in vertical polarization mode. The use of local optics corrections and/or lowering of beta functions were initially investigated as possible solutions but with limited success. Active shimming of dynamic multipoles, following the approach at BESSY-II, proved more effective. The optimum shiming has been devised using kick map approach. In this paper we review the theoretical analysis, the commissioning of the active shims and the undulator, and the net effect of the undulator after compensation.

TUPWO064

Online Optimization Algorithms for Accelerators and Experimental Results

injection, coupling, quadrupole, simulation

2012

X. Huang, W.J. Corbett, J.A. Safranek, J. Wu
SLAC, Menlo Park, California, USA

Online optimization of accelerators is becoming increasingly more important as accelerator systems become more and more complex. Online accelerator optimization is generally a multi-variant nonlinear problem with considerable noise. Efficiency and robustness are critical for online applications. Therefore optimization algorithms require special considerations. In this study we evaluate the viability of several online optimization algorithms for both ring and linac machines. Numerical simulations and experimental tests are presented to investigate performance of the algorithms.

TUPWO069

Optimization of FACET Optics

sextupole, lattice, chromatic-effects, simulation

2024

M.-H. Wang, F.-J. Decker, N. Lipkowitz, Y. Nosochkov, G.R. White, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Funding: supported by the US Department of Energy contract DE-AC02-76SF00515.
The FACET accelerator facility is designed to provide short and intense e^- or e⁺ bunches with small spot size for plasma wakefield accelerator research and other experiments. It is based on the SLAC linac with a compressor chicane in sector-10, and a second compressor chicane and final focus in sector-20 (S20). Originally, the S20 chicane was designed to be compatible with an upgrade to include a second S20 chicane for simultaneous transport of e^- and e⁺ bunches. This placed additional optics constraints which lead to strong focusing in the S20 chicane. The latter increases the effects of errors causing emittance growth. Lately, it has been decided not to proceed with the upgrade option. Therefore, there is a potential for improving the optics by relaxing the constraints. In this study, we explore alternative optics designs where beta functions in the S20 chicane and final focus are reduced in order to minimize the error effects. The optics and non-linear aberrations are evaluated, and the chromatic correction is optimized for each design. Beam tracking simulations are performed using Elegant and Lucretia. The most optimal designs are identified based on these simulations.

TUPWO073

Precision Tune, Phase and Beta Function Measurement by Frequency Analysis in RHIC

dipole, betatron, kicker, booster

2027

C. Liu, R.L. Hulsart, A. Marusic, R.J. Michnoff, M.G. Minty, P. Thieberger
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The high quality of the RHIC turn-by-turn (TbT) data obtained from the beam position monitor (BPM) system was fully exploited by using two analysis approaches. One is a time domain least square fitting technique and the other one is a frequency domain interpolated Fourier Transform technique. Both methods were applied to 1024-turn data from kicked beam and from continuous coherent excitation experiments. The betatron phase precisions obtained with both methods were ~0.1 degree for the continuous excitation and ~0.2 degree for the impulse excitation. The algorithms of these two analyses and comparison of their results will be presented in this report.

WEXB101

Optics Optimization for Reducing Collective Effects and Raising Instability Thresholds in Lepton and Hadron Rings

emittance, synchrotron, collective-effects, brightness

2033

Y. Papaphilippou, F. Antoniou, H. Bartosik
CERN, Geneva, Switzerland

This paper covers recent progress in the design of optics solutions to minimize collective effects such as beam instabilities, intra-beam scattering or space charge in hadron and lepton rings. The necessary steps are reviewed for designing the optics of high-intensity and high-brightness synchrotrons but also ultra-low emittance lepton storage rings, whose performance is strongly dominated by collective effects. Particular emphasis is given to proposed and existing designs illustrated by simulations and beam measurements.

Slides WEXB101 [24.511 MB]

WEOAB101

Single Particle Tracking for Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring

cavity, HOM, simulation, synchrotron

2038

M. Ruprecht, A. Jankowiak, A. Neumann, M. Ries, G. Wüstefeld
HZB, Berlin, Germany
T. Weis
DELTA, Dortmund, Germany

A scheme where 1.5 ps and 15 ps long bunches (rms) can be stored simultaneously in the BESSY II storage ring has recently been proposed (BESSY^VSR*). This paper presents simulations of single particle beam dynamics influenced by superconducting cavities used for the strong longitudinal beam focusing. The effect of RF jitter on (very short) bunches is investigated and results are discussed. Furthermore, possible effects on beam dynamics during ramp up and ramp down of the high gradient fields in the cavities are studied. The primary goal is to reveal preliminary design specifications for RF jitter on the basis of single particle dynamics.
* G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries, Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring, Proceedings of IPAC2011, San Sebastián, Spain

Slides WEOAB101 [3.955 MB]

WEOAB202

JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs

linac, electron, quadrupole, dipole

2085

S.A. Bogacz, G.A. Krafft, V.S. Morozov, Y. Roblin
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We propose a demonstration experiment for a new concept of a ‘dogbone’ RLA with multi-pass return arcs – JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security.

Slides WEOAB202 [1.485 MB]

WEOBB203

Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors

kicker, quadrupole, pick-up, target

2097

P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts
CERN, Geneva, Switzerland
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts
JAI, Oxford, United Kingdom
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
A. Ghigo, F. Marcellini
INFN/LNF, Frascati (Roma), Italy
E. Ikarios
National Technical University of Athens, Athens, Greece

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579
The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam.
We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.

Slides WEOBB203 [6.770 MB]

WEPWA004

Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes

linac, cryomodule, injection, acceleration

2129

Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
HZB, Berlin, Germany

The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability.

WEPWA030

Using the Power Spectral Density Method to Characterize and Evaluate the X-ray Mirrors Surfaces

synchrotron, simulation, focusing, brilliance

2196

W.Q. Hua, F.G. Bian, Y.M. He, W.H. Lin, L. Song, J. Wang, N. Zhao
SINAP, Shanghai, People's Republic of China

Rapid progress in synchrotron X-ray beams’ coherence and X-ray optics performance places a high demand on characterization and evaluation of optical surface figure and slope errors and roughness on meter-long optics over spatial frequencies as short as 0.1mm. In this paper, the propagation model of hard X-ray beams through reflecting mirror surface is proposed based on wave-front propagation, and numerical simulations are performed for predicting the hard X-ray focusing performance of different imperfect mirrors using a Fresnel diffraction calculation. The imperfect mirror surface height maps synthesized from power spectral functions are used to analyze and evaluate the influences of different mirror surface errors on the reflected hard X-ray beam properties.

WEPWA051

Extraction Beam Line for Light Sources

extraction, emittance, injection, kicker

2232

M. Aiba, M. Böge, T. Garvey, N. Milas, A. Saá Hernández, A. Streun
PSI, Villigen PSI, Switzerland

Most of measurements, with circulating beam in a ring, to determine transverse and longitudinal phase space volume are rather indirect although it is of importance to characterize these beam parameters for better understanding the machine. Direct measurements may be performed when the beam is extracted to a beam line, where destructive methods are available. However, light sources can tolerate internal beam dumping and thus do not have an extraction line in general. We, therefore, propose a diagnostic dedicated extraction line, motivated by precise determination of the geometrical vertical emittance, which can be a few pm or even less and general comparisons of direct and indirect measurements. Such an extraction beam line has been realized in several accelerator facilities, e.g. KEK-ATF. The idea is, however, to equip a compact beam line, which fits into the existing tunnel and allows us to measure transverse and longitudinal emittances. We present possible design of an extraction beam line assuming typical light source parameters.

WEPEA021

Influence of the Vacuum Chamber Limitation on Dynamic Aperture Calculations

dynamic-aperture, vacuum, multipole, resonance

2543

M. Attal
SESAME, Allan, Jordan

In a storage ring the evaluation of the dynamic aperture taking into account the vacuum chamber limitation is more accurate and may display nonlinearities that could not be seen in the conventional absolute dynamic aperture calculations. This has been investigated in this paper and demonstrated in SESAME dynamic aperture case where taking into account the vacuum chamber uncovered the seriousness of a 5th order resonance mainly when errors like high order multipoles were introduced to the lattice. The destructive effect of the 5th order resonance has been avoided by changing the fractional part of the tunes. The problem has also been more investigated using the Frequency Map Analysis technique.

WEPEA045

Specifications of the Field Quality at Injection Energy of the New Magnets for the HL-LHC Upgrade Project

injection, dynamic-aperture, multipole, simulation

2603

R. De Maria, S.D. Fartoukh, M. Giovannozzi
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The HL-LHC project relies on new magnet designs and technologies to achieve very small β^* values. In particular, Nb3Sn magnets show large allowed multipole imperfections at low current. These field errors may have a non-negligible impact on the dynamic aperture and beam life time in the HL-LHC, also because of the smaller-than-nominal β^* values foreseen IR1 and IR5 at injection energy, which aims at decreasing the dynamic range of the squeeze and therefore contributing to optimize the turn around time. The paper describes an analysis of the machine performance based on analytical estimates and tracking simulations with the goal of providing field quality specifications for the new magnets.

WEPEA047

Dynamic Aperture Performance for Different Collision Optics Scenarios for the LHC Luminosity Upgrade

multipole, luminosity, dynamic-aperture, injection

2609

M. Giovannozzi, R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland
A. Chancé, B. Dalena, J. Payet
CEA/IRFU, Gif-sur-Yvette, France
K.M. Hock, M. Korostelev, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The ATS[1] optics solution for the HL-LHC offers the possibility of different collision optics, with a β^* as small as 10 cm in both transverse planes, or with a β^* aspect ratio of up to 4 pushing β^* to even smaller value (5cm) in the parallel separation plane while relaxing it (20 cm) in the crossing plane. The latter configuration features two possible options for alternated orientations of the crossing plane in the two high luminosity insertions, both considered in this study. In this paper we study the impact of few selected field imperfection models of the new magnets foreseen for the upgrade through tracking simulations and scaling laws.
[1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA048

Specification of a System of Correctors for the Triplets and Separation Dipoles of the LHC Upgrade

multipole, dipole, simulation, insertion

2612

M. Giovannozzi, R. De Maria, S.D. Fartoukh
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The luminosity upgrade of the LHC aims at reducing β^* from 55 cm to 15 cm or beyond. This can be achieved by the ATS* scheme and means of new large aperture superconducting triplet (IT) quadrupoles (150 mm), preferably using the Nb3Sn technology in order to keep the gradient reasonably high (140 T/m). The field quality requires careful specification in order to ensure a large enough dynamic aperture. In this context, dedicated corrector magnets are foreseen to provide semi-local corrections of specific multipole components and find the best possible compromise between the demand and what can be realistically achieved by the magnet manufacturer. In this paper the layout and main parameters of the IT corrector package are presented together with the correction strategy. Moreover, the foreseen performance is discussed in detail.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA049

Analysis of the Non-linear Fringe Effects of Large Aperture Triplets for the HL LHC Project

quadrupole, dipole, simulation, luminosity

2615

A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov
BINP SB RAS, Novosibirsk, Russia
A. Chancé, B. Dalena, J. Payet
CEA/IRFU, Gif-sur-Yvette, France
R. De Maria, S.D. Fartoukh, M. Giovannozzi
CERN, Geneva, Switzerland

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404.
The HL-LHC project relies on large aperture quadrupoles which are compatible with the very large beam sizes in the inner triplets resulting from the strong reduction of β^*. As a result the beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. The spatial extension of these fringe fields increases as well more or less linearly with the coil aperture, which is an additional motivation to analyse this aspect in detail in the framework of the High Luminosity LHC design study. This paper will quantify this effect both by direct analytical estimates using first order Hamiltonian perturbation theory, and via numerical studies thanks to the dedicated implementation of a fringe field symplectic integrator in SixTrack.

WEPEA054

CERN PS Optical Properties Measured with Turn-by-turn Orbit Data

resonance, simulation, extraction, kicker

2627

C. Hernalsteens, T. Bach, S.S. Gilardoni, M. Giovannozzi, A. Lachaize, G. Sterbini, R. Tomás, R. Wasef
CERN, Geneva, Switzerland

The performance of the PS has been constantly increasing over the years both in terms of beam parameters (intensity and brightness) and beam manipulations (transverse and longitudinal splitting). This implies a very good knowledge of the linear and non-linear model of the ring. In this paper we report on a detailed campaign of beam measurements based on turn-by-turn orbit data aimed at measuring the optics in several conditions as well as the resonance driving terms. The goal of this study is to assess whether any specific correction system should be envisaged to achieve the required future performance.

WEPEA058

LSS Layout Optimizations for Low-beta Optics for the HL-LHC

quadrupole, sextupole, luminosity, chromatic-effects

2639

B.J. Holzer, R. De Maria
CERN, Geneva, Switzerland
R. Appleby, L.N.S. Thompson
UMAN, Manchester, United Kingdom
L.N.S. Thompson
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
The High Luminosity LHC (HL-LHC) project aims to upgrade the existing LHC to a peak luminosity of the order 10³⁵cm^-2s⁻¹, while retaining as much of the nominal layout and hardware as possible. The current baseline for this upgrade is the use of the Achromatic Telescopic Squeeze (ATS) concept, which allows mini-Beta squeeze in IRs 1 and 5 (ATLAS and CMS respectively) far below that possible with nominal optics. However it is useful to both explore the parameter space of the ATS scheme while also attempting to push the boundaries of the nominal layout. This paper presents a study into maximising optical flexibility of the nominal LHC Long Straight Sections (LSSs) around IPs 1 and 5. This involves replacing, moving or adding magnets within the LSS to investigate feasibility of exploiting a more conventional optical scheme than the ATS scheme. In particular the option of replacing single LSS quadrupoles with doublets is explored. The study also looks at making similar changes to the LSS while also implementing the ATS scheme, to further explore the ATS parameter space with the benefit of experience gained into flexibility of a modified nominal LHC optical scheme.

WEPEA059

Study of the Impact of Fringe Fields of the Large Aperture Triplets on the Linear Optics of the HL-LHC

quadrupole, luminosity, collider, focusing

2642

B.J. Holzer, R. De Maria, S. Russenschuck
CERN, Geneva, Switzerland
R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
UMAN, Manchester, United Kingdom
L.N.S. Thompson
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
High-luminosity hadron colliders such as the High Luminosity LHC (HL-LHC) project place demanding requirements on existing and new magnet technology. The very low β^* achieved by the Achromatic Telescopic Squeeze (ATS) optics scheme* for the HL-LHC in particular, requires large apertures in the high gradient Nb3Sn final focusing inner triplet triplet. Such magnets have extended fringe fields which perturb the linear and non-linear optics. This paper presents results of studies into the liner optics of the LHC using a range of fringe field models, including measurements of fringe fields from prototype magnets, and presents calculations of the beta-beating in the machine. Furthermore a similar study is presented on the nominal LHC optics, which uses final focus quadrupoles of higher gradient but significantly smaller aperture.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for
LHC Upgrade’’, in proceedings of IPAC11, p. 2088.

WEPEA067

Beam Optics Measurements through Turn by turn Beam Position Data in the SLS

betatron, storage-ring, luminosity, positron

2663

P. Zisopoulos, Y. Papaphilippou
CERN, Geneva, Switzerland
A. Streun
PSI, Villigen PSI, Switzerland
V.G. Ziemann
Uppsala University, Uppsala, Sweden

Refined Fourier analysis of turn-by-turn (TBT) transverse position data measurements can be used for determining several beam properties of a ring, such as transverse tunes, optics functions, phases, chromatic properties and coupling. In particular, the Numerical Analysis of Fundamental Frequencies (NAFF) algorithm is used to analyze TBT data from the Swiss Light Source (SLS) storage ring in order to estimate on and off-momentum beam characteristics. Of particular interest is the potential of using the full position information within one turn in order to measure beam optics properties.

WEPEA082

AGS Model in Zgoubi. RHIC Run 13 Polarization Modeling. Status.

simulation, polarization, extraction, injection

2699

F. Méot, L. A. Ahrens, K.A. Brown, Y. Dutheil, J.W. Glenn, C.E. Harper, H. Huang, V.H. Ranjbar, T. Roser, V. Schoefer, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
This paper gives a status of the AGS model in the ray-tracing code Zgoubi and its operation via the ‘‘AgsZgoubiModel'' and the ‘‘AgsModelViewer'' applications available from the controls system application launcher, ‘‘StartUp''. Examples of typical uses and studies performed using these are included, as optics controls, spin matching to RHIC, etc. A companion paper (MOPWA085) gives additional details, regarding especially spin dynamics and polarization studies aimed at determining optimal AGS settings for polarization during RHIC Run 13. This work is an additional step towards further combination with the already existing RHIC spin tracking model in Zgoubi, and AGS's Booster model in Zgoubi, a promising suite for detailed beam and spin dynamics studies and optimizations.

WEPME003

Determination of Optics Transfer between the Kicker and BPMs for Transverse Feedback System

kicker, feedback, betatron, synchrotron

2923

M. Alhumaidi, A.M. Zoubir
TU Darmstadt, Darmstadt, Germany
J. Grieser
TU Darmstadt, RTR, Darmstadt, Germany

The knowledge of the transfer optics between the positions of the Kicker and the BPMs is required for the calculation of the correction signal in transverse feedback systems. Therefore, using nominal values of the transfer optics with uncertainties leads to feedback quality degradation, and thus beam disturbances. In this work, we propose a method for measuring the phase advances and amplitude scaling between the positions of the kicker and the BPMs. Directly after applying a kick on the beam by means of the kicker, we record the BPM signals. Consequently, we use the Second-Order Blind Identification (SOBI) algorithm to decompose the noised recorded signals into independent sources mixture. Finally, we determine the required optics parameters by identifying and analyzing the betatron oscillation sourced from the kick based on its mixing and temporal patterns. Results for the heavy ions synchrotron SIS 18 at the GSI are shown.

WEPME055

Investigation of Source Point Instabilities in Dipole Magnet Based Beamlines

dipole, synchrotron, feedback, radiation

3055

M. Apollonio, R. Bartolini
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

At Diamond the source point in the second dipole of the Double Bend Achromats can vary due the lack of adjacent BPMs constraining angle and position of the electron beam at the dipole. We have implemented a code based on our AT model to predict the effects of a corrector strength change and compared our predictions to data both from a beamline and from our pinhole cameras. We discuss the possibility of interfacing the code to a ray tracing routine in order to infer beam spot changes in the downstream beamline and suggest a procedure to restore the original source point.

THPEA046

Machine Protection at the LHC - Experience of Three Years Running and Outlook for Operation at Nominal Energy

injection, feedback, synchrotron, extraction

3246

D. Wollmann, R. Schmidt, J. Wenninger, M. Zerlauth
CERN, Geneva, Switzerland

With above 22fb-1 integrated luminosity delivered to the experiments ATLAS and CMS the LHC surpassed the results of 2011 by more than a factor 5. This was achieved at 4TeV, with intensities of ~2e14p per beam. The uncontrolled loss of only a small fraction of the stored beam is sufficient to damage parts of the sc. magnet system, accelerator equipment or the particle physics experiments. To protect against this a correct functioning of the complex LHC machine protection (MP) systems through the operational cycle is essential. Operating with up to 140MJ stored beam energy was only possible due to the experience and confidence gained in the two previous running periods, where the intensity was slowly increased. In this paper the 2012 performance of the MP systems is discussed. The strategy applied for a fast, but safe, intensity ramp up and the monitoring of the MP systems during stable running periods are presented. Weaknesses in the reliability of the MP systems, set-up procedures and setting adjustments for machine development periods, discovered in 2012, are critically reviewed and improvements for the LHC operation after the up-coming long shut-down of the LHC are proposed.

THPWA004

The HIT Gantry: From Commissioning to Operation

ion, proton, dipole, diagnostics

3636

M. Galonska, S. Brons, R. Cee, Th. Haberer, K. Höppner, J.M. Mosthaf, A. Peters, S. Scheloske, T. Winkelmann
HIT, Heidelberg, Germany

The patient treatment at the first 360° raster scanning heavy ion gantry of the Heidelberg Ion Therapy Facility (HIT) started in October 2012 using proton and carbon ion beams. HIT is the first dedicated proton and carbon cancer therapy facility in Europe. It uses full 3D intensity controlled raster scanning dose delivering method of pencil beams. The ion energy ranges from ~50 up to 430 MeV/u (ion penetration depths of 20 to 300 mm in water). Beams are provided by a linac-synchrotron-system to four high energy beam lines: 2 horizontal patient treatment rooms; 1 horizontal experimental cave for quality assurance, development, and research work; and the heavy ion gantry. From the first commissioning the libraries of carbon and proton pencil beams at the gantry had been offered with the whole variety of ion beam properties: 255 energy steps, 4 beam foci, 360°, and 10 intensities (10⁶-10¹⁰/spill) regarding the central beam. This paper reflects the impact of the subsequent preclinical testing including beam size/position, and dose measurements within the irradiation field of 20x20 cm² on the further improvement of the ion optical settings of the gantry high energy transfer line.

THPWO046

The Preparation for the Commissioning of CSNS Accelerators

injection, DTL, linac, target

3872

S. Wang, S. Fu, H.F. Ouyang, J. Peng
IHEP, Beijing, People's Republic of China

The China Spallation Neutron Source (CSNS) is now under construction, and the beam commissioning of ion source will start from the end of 2013, and will last several years for whole accelerators. The commissioning plan for the CSNS accelerators will be presented, including the commissioning correlated parameters, beam instrumentation in used commissioning, the goal at different commissioning stages. The development of high level application software will also be presented.

THPWO065

Optics Design and Correction of High Order Aberration of the Charge Stripper Beam Line of RAON

stripper, sextupole, ion, emittance

3906

H.J. Kim, D. Jeon, H.J. Kim
IBS, Daejeon, Republic of Korea
J.G. Hwang, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea

RAON (Rare isotope Accelerator Of Newness) in Korea will be providing the 400 kW of 238U⁷⁹⁺ beam with 8 puA and 200 MeV/u. One of the critical components of this project in the SCL is the design of the charge stripper. Between the two segments of the SCL, the charge stripper strips electrons from ion beams to enhance the acceleration efficiency in the following SCL2. For high efficiency of the acceleration and high power in SCL2, the optimum energy of striped ion in solid carbon foil stripper for SCL1 was estimated by using code LISE. The thickness of the solid carbon foil is 300 ug/m2. Based on this study, the charge stripping efficiency of solid carbon stripper is ~80 %. For the charge selection from ions which produced by the solid carbon stripper, the dispersive section is required in down-stream of the foil. The designed optics for dispersive section is based on the mirror-symmetric optics to minimize the effect of high-order aberration. And the high-order aberration in designed optics was investigated and performed the correction of high-order effect using sextupole magnets.

THPWO080

Operational Performance of the LHC Proton Beams with the SPS Low Transition Energy Optics

emittance, brightness, extraction, injection

3945

Y. Papaphilippou, G. Arduini, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, C. Bracco, S. Cettour-Cave, K. Cornelis, L.N. Drøsdal, J. Esteban Müller, B. Goddard, A. Guerrero, W. Höfle, V. Kain, G. Rumolo, B. Salvant, E.N. Shaposhnikova, H. Timko, D. Valuch, G. Vanbavinckhove, J. Wenninger
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, USA

An optics in the SPS with lower integer tunes (20 versus 26) was proposed and introduced in machine studies since 2010, as a measure for increasing transverse and longitudinal instability thresholds, especially at low energy, for the LHC proton beams. After two years of machine studies and careful optimisation, the new “Q20” optics became operational in September 2012 and steadily delivered beam to the LHC until the end of the run. This paper reviews the operational performance of the Q20 optics with respect to transverse and longitudinal beam characteristics in the SPS, enabling high brightness beams injected into the LHC. Aspects of longitudinal beam stability, transmission, high-energy orbit control and beam transfer are discussed.

THPWO081

Design Options of a High-power Proton Synchrotron for LAGUNA-LBNO

space-charge, dipole, proton, emittance

3948

Y. Papaphilippou, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, I. Efthymiopoulos, R. Garoby, F. Gerigk, B. Goddard, C. Lazaridis, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg
CERN, Geneva, Switzerland

Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology beam loss control and RF considerations. Optics optimization studies are also presented including beam transfer and collimation considerations.

THPWO083

Simulation of a Beam Rotation System for the SINQ Spallation Source at PSI

target, proton, simulation, neutron

3954

D. Reggiani, T. Reiss, M. Seidel, V. Talanov, M. Wohlmuther
PSI, Villigen PSI, Switzerland

With a nominal beam power of nearly 1 MW on target, the PSI-SINQ ranks among the world's most powerful neutron spallation sources. The proton beam transport to the SINQ target is carried out exclusively by means of linear elements. As a consequence, at the SINQ target entrance the beam presents Gaussian transverse x and y distributions with tails cut short by collimators. This leads to a highly uneven temperature distribution inside the SINQ zircaloy target, giving rise to thermal and mechanical stress. In view of a future beam intensity upgrade, the possibility of homogenizing the beam distribution by means of a fast beam rotation system is currently under study. Important aspects of this method concern the resulting neutron spectrum and flux distribution. The simulations of the beam distribution achievable thanks to this technique as well as its consequences in terms of neutron production are presented in this contribution.

THPWO092

Update of Beam Optics and SRF Cavities for Project X

linac, cavity, cryomodule, solenoid

3975

T.N. Khabiboulline, P. Berrutti, V.A. Lebedev, A. Lunin, T.H. Nicol, J.-F. Ostiguy, T.J. Peterson, L. Ristori, A. Saini, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

The Project X staging [1] requires reconsideration of the beam optics and thus, the SRF system for the 3 GeV CW linac of the Project X. The revised beam optics is presented in the paper as well as revised cavity design for SSR2 section and a new concept of the linac segmentation. The new versions for the Project X cryo-modules for the SSR2 section, low-beta 650 MHz section and high-beta 650 MHz section are discussed. The beam extraction scheme at 1 GeV is discussed also. [1] S. Holmes, “Project X News, Strategy, Meeting Goals,” 2012 Fall Project X Collaboration Meeting, 27-28 November 2012, Fermilab.