05 Beam Dynamics and Electromagnetic Fields
D01 Beam Optics - Lattices, Correction Schemes, Transport
Paper Title Page
MOYCA01 Review of Linear Optics Measurements and Corrections in Accelerators 20
 
  • R. Tomás
    CERN, Geneva, Switzerland
  • M. Aiba
    PSI, Villigen PSI, Switzerland
  • A. Franchi
    ESRF, Grenoble, France
  • U. Iriso
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  The measurement and correction of optics parameters has been a major concern since the advent of strong focusing synchrotron accelerators. Traditionally, colliders have led the development of methods for optics control based on turn-by-turn centroid data, while lepton storage rings have focused on closed orbit response techniques. Recently considerable efforts are being invested in comparing these techniques in different light sources and colliders. An emerging class of less invasive optics control techniques based on the optimization of performance related observables is demonstrating a great potential. A review of the existing techniques is presented highlighting comparisons, merits and limitations.  
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TUOAB01 Optimization of the Dechirper for Electron Bunches of Arbitrary Longitudinal Shapes 1054
SUPSS049   use link to see paper's listing under its alternate paper code  
 
  • J.M. Seok, M. Chung
    UNIST, Ulsan, Republic of Korea
  • J.H. Han, J.H. Hong, H.-S. Kang
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Dechirper is a passive device composed of a vacuum chamber of two corrugated, metallic plates with an adjustable gap. By introducing a small offset in the dechirper with respect to the reference axis, one might generate transverse wakefields and use the dechirper as a deflector. Understanding the interactions between electron beams of various longitudinal shapes with the wakefields generated by the dechirper is important to assess the feasibility of the dechirper for use as a deflector. Recently, using a set of alpha-BBO crystals, shaping of laser pulses and electron bunches on the order of ps is tested at the Injector Test Facility (ITF) of Pohang Accelerator Laboratory (PAL). Furthermore, we have investigated propagation of electron bunches of arbitrary longitudinal shapes through the dechirper. In the numerical simulations, we observed that the arbitrary electron beams were successful deflected except for lethal beam shape problems. Hence, in this work, we study optimization of the dechirper for electron bunches of arbitrary longitudinal shapes, using analytical theory and numerical simulations with the ASTRA and ELEGANT codes.  
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THOBA03 Start-to-end Calculations and Trajectory Correction for BERLinPro 3167
 
  • B.C. Kuske, C.J. Metzger-Kraus
    HZB, Berlin, Germany
 
  Funding: Work funded by the Bundesministerium für Bildung und Forschung, Land Berlin and grants of the Helmholtz Association
BERLinPro is an ERL project under construction at the Helmholtz-Zentrum Berlin, with the goal to illuminate the challenges and promises of a high brightness 100 mA superconducting RF gun in combination with a 50 MeV return loop and energy recovery. Latest changes to the optics code OPAL allow for the first time to perform start-to-end tracking studies including space charge in a single run, without switching between codes. This opens the way to apply correction schemes to displaced trajectories in the complete machine and to study the effect of jitter sources, including the space charge dominated injector, on the machine performance parameters. Trajectory correction is discussed. Jitter is studied with respect to its potential impact on the recovery process and parameter changes before the dump.

 
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THPMB001 Muon Production via the ESSnuSB Project 3213
 
  • E. Bouquerel, E. Baussan, M. Dracos
    IPHC, Strasbourg Cedex 2, France
  • N. Vassilopoulos
    IHEP, Beijing, People's Republic of China
 
  Funding: This project is now supported by the COST Action CA15139 "Combining forces for a novel European facility for neutrino-antineutrino symmetry-violation discovery" (EuroNuNet).
ESSnuSB plans to produce very intense neutrino beams using the protons from the ESS linac (5 MW, 2 GeV) and a 4-targets horn system. In the ESSnuSB proposed facility a copious number of muons will also be produced. These muons could be used by a future Neutrino Factory to study CP violation in the leptonic sector but also to study neutrino cross-sections. They could also be used to feed a future muon collider. The feasibility and the issues of extracting the intense muon beam produced together with neutrinos are discussed.
 
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THPMB002 Beam Dynamics and Closed Orbit Correction at the Collector Ring 3216
 
  • O.E. Gorda, A. Dolinskyy, O.A. Kovalenko
    GSI, Darmstadt, Germany
  • I. Koop, D.B. Shwartz
    BINP SB RAS, Novosibirsk, Russia
  • Yu. A. Rogovsky
    Budker INP & NSU, Novosibirsk, Russia
 
  The Collector Ring (CR) has been designed for fast cooling of hot antiproton or ion beams at FAIR. Its ion-optical layout and system design has been recently finalized after careful optimizations aiming at improvement of the beam parameters and machine performance. In this paper we present the simulations of the transverse beam dynamics for the different ion-optical modes of the CR. Particle tracking calculations have been performed to evaluate an influence of the magnet imperfections on the dynamic aperture. The analysis and correction of the closed orbit distortions due to the magnet misalignments is also discussed.  
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THPMB003 Orbit Response Matrix Analysis for FAIR Storage Rings 3219
 
  • O.A. Kovalenko, A. Dolinskyy, O.E. Gorda, S.A. Litvinov
    GSI, Darmstadt, Germany
 
  The Orbit Response Matrix (ORM) analysis is a method which allows to find the sources of discrepancies between design and real optics of an accelerator machine. In particular, with this technique one retrieves information about gradient errors, dipole corrector gain errors etc. Orbit response matrix is computed by measuring orbit deviations caused by single kicks of corrector magnets. With fitting the matrix one obtains the ion optics which best describes the real accelerator. The ORM analysis, presented in the paper, is employed to find error sources in the FAIR storage rings CR and HESR during and after the beam commissioning. The algorithm itself was implemented in Python programming language with a help of linear algebra libraries. The ORM analysis accuracy as well as its limitations are addressed in the paper.  
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THPMB004 Improving Energy Spread and Stability of a Recirculating Few-turn Linac 3222
 
  • F. Hug
    IKP, Mainz, Germany
  • M. Arnold, T. Kürzeder, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • R.G. Eichhorn
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Supported by the DFG through CRC 634, RTG 2128 and PRISMA cluster of excellence
A non-isochronous recirculation scheme which helps cancelling out errors coming from the RF-jitters in a recirculating linac will be presented. Non-isochronous recirculation is the common operation mode for synchrotrons or microtrons. In such a scheme the recirculation arcs provide a non-zero longitudinal dispersion, while the particle bunches are accelerated at a certain phase off-crest with respect to the maximum of the accelerating field. In few-turn linacs and microtrons such beam dynamics can be used to reduce the energy spread. To do so the longitudinal phase advance needs to be set to a half-integer number of oscillations in phase space. Then errors from linac RF-systems cancel out and the energy spread remains closely to the value at injection. In addition to the improved energy spread the beam stability of few-turn recirculators can be increased as well using such a system. We will present operational experience with the non-isochronous recirculation system of the twice recirculating superconducting accelerator S-DALINAC operated at TU Darmstadt including beam-dynamics calculations and measurements of the energy spread.
 
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THPMB005 Notes on Steffen Parameters of Extended Fringe-Field Quadrupoles 3226
 
  • V. Balandin, W. Decking, N. Golubeva
    DESY, Hamburg, Germany
 
  We consider some theoretical aspects of the Steffen hard-edge model of quadrupoles with extended fringe-fields and discuss possibilities of usage of this model in online beam dynamics applications.  
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THPMB006 Unclosed Lattice Dispersions as a Tool for Partial Removal of Transverse to Longitudinal Beam Correlations 3229
 
  • V. Balandin, W. Decking, N. Golubeva
    DESY, Hamburg, Germany
 
  We show how to choose unclosed lattice dispersions in order to zero either linear beam dispersions (linear correlations between energy of particles and their transverse positions and momenta) or linear beam tilts (linear correlations between longitudinal positions of particles and their transverse coordinates). Besides that, we prove that while removal of beam dispersions always leads to reduction of transverse projected emittances, zeroing of beam tilts cannot guarantee it.  
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THPMB007 Numerical Computation of Transport Matrices of Axisymmetric RF Cavities for Online Beam Dynamics Applications 3233
 
  • V. Balandin, W. Decking, N. Golubeva
    DESY, Hamburg, Germany
 
  The RF focusing effect plays a considerable role at low particle energies and cannot be neglected in many online beam dynamics applications. Unfortunately, known analytical expressions for the transfer matrix of a cavity typically are applicable only to ultra-relativistic beams and demonstrate notable differences with accurate numerical simulations at low energies. So, in this paper, we present practical numerical algorithm for calculation of the linear transfer matrices of axisymmetric RF cavities which we developed for online modeling of the beam dynamics in the European XFEL linac.  
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THPMB008 Compensation of Steerer Crosstalk between FLASH1 and FLASH2 3237
 
  • F. Christie, B. Schmidt, M. Vogt
    DESY, Hamburg, Germany
 
  The free-electron laser in Hamburg (FLASH) is a user facility delivering soft X-ray radiation. Starting from 2014, a second beam line for user operation, FLASH2, has been commissioned. It uses the same accelerating modules as the initial FLASH beam line (FLASH1) and the beam is deflected into a separate beam line downstream the linac. In the region, where the FLASH2 beam is extracted, both beam lines are close, the angle in between is 6.5 degrees. It has been observed, that steering dipoles in the extraction area, have an influence on both beam lines. Thus steering the orbit in one beam line, perturbs the orbit in the other beam line. This perturbation can significantly degrade the SASE energy in the other beam line. We have found a solution to this problem based the combination of local orbit bumps. The crosstalk from one steerer is corrected using additional steerers in the other beam line. This concept has already been tested at FLASH and has proven to work sufficiently well.  
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THPMB009 Model Driven Machine Improvement of COSY Based on ORM Data 3240
 
  • C. Weidemann, M. Bai, F. Hinder, B. Lorentz
    FZJ, Jülich, Germany
 
  The COoler SYnchrotron in Jülich accelerates and stores unpolarized and polarized proton or deuteron beams in the momentum range between 0.3 GeV/c and 3.65 GeV/c [*,**]. This, in combination with its diverse capabilities of phase space cooling and the flexibility of the lattice with respect to ion-optical settings makes COSY an ideal test facility for accelerator technology development. High demands on beam control and beam based measurements have to be fulfilled for future experiments such as the proposed precursor experiment for a direct measurement of the electric dipole moment of the deuteron (see [***] and references within). The analysis of measured orbit response matrices (ORM), which com- prise the focussing structure of the ring, allows for a better understand- ing of machine imperfections such as gradient errors and misalignments of quadrupole magnets. This contribution presents the development of a MAD-X based LOCO (Linear Optics from Closed Orbits) algorithm [****] in a C++ program aiming to calibrate and correct linear optics as well as improving beam control at COSY.
* R. Maier, NIM A 390, 1 (1997).
** S.A. Martin et al., NIM A 236, 249-255 (1985).
*** D. Eversmann et al. [JEDI Collaboration], Phys. Rev. Lett. 115, 094801 (2015).
**** J. Safranek, NIM A 388, 27 (1997).
 
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THPMB010 Dogleg Design for the SINBAD Linac 3244
 
  • J. Zhu, R.W. Aßmann, U. Dorda, B. Marchetti
    DESY, Hamburg, Germany
  • R. Rossmanith
    KIT, Karlsruhe, Germany
 
  The SINBAD facility (Short and INnovative Bunches and Accelerators at DESY) is foreseen to provide sub-fs to tens of fs electron bunches for the R&D of novel acceleration concepts and applications, e.g. Laser Wake-Field Acceleration (LWFA), Dielectric Laser Acceleration (DLA) and medical imaging. We present the design study of the dogleg at the SINBAD linac, which is capable of delivering ultra-short bunches to the second beamline. The longitudinal dispersion of the dogleg can be finely tuned so that it can either transport the ultra-short bunch produced upstream by velocity bunching, or compress the incoming long bunch. The achievable beam parameters are investigated by start-to-end simulations.  
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THPMB011 Beam Based Alignment Methods for Cavities and Solenoids in Photo-Injectors 3247
 
  • M. Rossetti Conti
    Universita' degli Studi di Milano & INFN, Milano, Italy
  • A. Bacci
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
 
  Solenoids are often used as lens-like beam focusing elements in electron linacs, especially in the low energy beam lines aside the Gun solenoid for emittance compensation, a common element of high brightness photo-injectors. There are also many electron linacs worldwide which use the Velocity Bunching beam compression technique, which needs solenoids wrapping the first acceleration cavity. A misalignment between the beam trajectory and the magnetic center of the solenoids produces a decrease in the beam quality and makes it necessary to find a complex steering setting to force the beam on a good orbit. In this proceeding we present a study of two beam based alignment techniques, which are correlated: the first shows a method to find the correct electromagnetic axis of an acceleration cavity, the second shows how to align the solenoids (wrapping the cavity) on this axis. Therefore the study permits to find the best steering setting and the solenoids positions corrections which have to be done. The work is based on real data acquired on the SPARC linac and on a virtual experiment.  
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THPMB012 The HMBA Lattice Optimization for the New 3 GeV Light Source 3251
 
  • K. Harada, M. Adachi, N. Funamori, T. Honda, Y. Kobayashi, N. Nakamura, K. Oide, H. Sakai, S. Sakanaka, K. Tsuchiya
    KEK, Ibaraki, Japan
 
  For the design study of the HMBA (hybrid multi bend achromat) type most advanced light source, the new storage ring was designed from the lattice of the phase II upgrade project of the ESRF (ESRF II). Although the original 3 GeV test lattice from Dr. Pantaleo Raimondi of ESRF has no problem about the optical and magnetic parameters including the dynamic aperture, we reduce the cell numbers and inserted the short straight sections for the in-vacuum short-gap undulators. After the optimization of the linear and non-linear optics as the original design principle of ESRF II, the altered lattice has the circumference of about 440 m with 16 HMBA cells, the emittance about 440 pm rad with the intra-beam scattering effect at the beam current of 500 mA, and the large dynamic aperture of about 2 cm at the injection point even with the usual magnetic errors.  
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THPMB013 Proposal of 6 GeV Energy Recovery Linac Hybrid Machine 3254
 
  • M. Shimada, K. Yokoya
    KEK, Ibaraki, Japan
  • R. Hajima
    JAEA, Ibaraki-ken, Japan
  • M. Tecimer
    University of Hawaii at Manoa, Honolulu, USA
 
  We proposed 6 GeV Energy Recovery Linac (ERL) as an intense gamma-ray source for the polarized positron source of International Linear Collider (ILC)*. In this scheme, Coherent Synchrotron Radiation from quasi-CW 6 GeV electron beam is stacked in optical cavity at middle infrared region, and it is used for inverse Compton scattering to generate 10 MeV polarized gamma-ray. The same 6 GeV superconducting linac accelerates both the electron and positron beams up to 5 GeV for injection to the dumping ring. Furthermore, it is available for X-ray light source by adding another recirculation loop. It can be expected as a diffraction limit light source at 10 keV, and the target of the brilliance is 1022-23 ph/s/mm2/mrad2/b.w.0.1%.
* M. Shimada, Proceedings of IPAC'13
 
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THPMB015 Muon Charge Separation by Mixed Structure of Dipoles and Solenoids 3257
SUPSS050   use link to see paper's listing under its alternate paper code  
 
  • Y.P. Song, H.T. Jing, J.Y. Tang
    IHEP, Beijing, People's Republic of China
 
  A charge separation system comprised by dipoles and solenoids is described which aims to separate positive particles and negative particles apart in secondary beam with a large emittance and huge momentum spread, particularly for mixed-charge muon beams. Nonlinear effect and fringe field effect due to large aperture and large moment range are crucial under this circumstance, which make the charge separation extremely complicated. The design schemes by dipoles and bent solenoids and also simulation results are showed in the paper.  
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THPMB017 The Errors Study on a Recent Heps Low-Beta Design 3260
 
  • D. Ji, Y. Jiao, G. Xu
    IHEP, Beijing, People's Republic of China
 
  The next synchrotron light source High Energy Photon Source is currently studied at Beijing. A nominal design for the HEPS, in a hybrid 7BA lattice and with an emittance of 60 pm.rad in a circumference of 1.3 kilometers, is completed for further study. In this paper, we present some work on error effect based on the nominal lattice design. Topics covered include dynamic aperture and beam parameters affected by magnetic field error, systematic and random multipole errors and misalignment effect.  
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THPMB018 Candidate Booster Design for the HEPS Project 3263
 
  • Y.M. Peng, Y.Y. Guo, Y. Jiao, Y. Wei, G. Xu
    IHEP, Beijing, People's Republic of China
 
  The High Energy Photon Source (HEPS), with trans-verse emittances of a few tens of pm.rad, is to be built in the suburbs of Beijing, China. The HEPS booster is a 2 Hz electron synchrotron. It accelerates electron bunches from a 300 MeV linac to a final energy of 6 GeV, and then extracts and injects them into the stor-age ring. We have made a candidate booster design, with a circumference of about 432 m and a natural emittance of about 4 nm.rad at 6GeV, which will be located in a separate tunnel. This lattice has a four-fold symmetry. Each super-period is composed of 13 iden-tical cells and two matching cells. The lattice design and optimization and other considerations are present-ed in a detail.  
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THPMB021 Design of the Magnets of the Far-Infrared FEL Project at NSRL 3269
 
  • T.L. He, H. Xu, W. Xu, S.C. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: National Natural Science Foundation of China (10875118); National Natural Science Foundation of China (11375176)
This paper describes the magnetic design of the magnets of the far-infrared free electron laser at NSRL, including dipole magnets and quadrupole magnets with limited installing space. The dipoles are of three different effective lengths and strengths. All the magnets are designed and optimized by using POSSION and OPERA-3D. The end shimming and chamfer are modeled and fully determined by 3D simulation to meet the field uniformity requirement. The design consideration and simulation results are presented in detail.
 
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THPMB022 Direct and High Resolution Beta-Function Measurements for Storage Ring Lattice Characterization 3272
 
  • W. Li, H. Hao, Y.K. Wu
    FEL/Duke University, Durham, North Carolina, USA
  • W. Li, W. Xu
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Betatron functions are a set of commonly used merits to characterize the lattice performance of a circular accelerator. The betatron functions in many accelerators can be computed using a lattice model trained or calibrated using a set of closed orbit responses, which is exemplified by the widely used LOCO technique. However, for some accelerators, like Duke storage ring with quad-sextupole combined function magnets, LOCO cannot be employed in any straight forward manner. In this case, direct measurements for betatron function are required. One way to determine betatron functions at the location of quadrupoles for a circular accelerator is to use the relationship between the quadrupole strength variations and the corresponding betatron tune change. In this paper, we present a set of carefully developed techniques to accurately measure the betatron functions at the location of quadrupoles, which allow us to achieve extremely high accuracy. Measurement errors will be discussed, and the detailed measurement technique will be present. Finally, we'll report preliminary experimental results of beta function measurements in the Duke storage ring with statistical error on the order of 1%.  
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THPMB023 Lattice Compensation of the Wiggler Effect in HLSII with Particle Swarm Optimization 3275
 
  • G. Liu, L. Wang, K. Xuan
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  The upgrade project of Hefei Light Source (HLSII) has successfully reduced the natural emittance of the electron beam to lower than 40 nm·rad at 800 MeV with five insertion devices installed. To provide enough straight sections for these insertion devices, the lattice structure has been changed to four double bend achromatic (DBA) with two super-periods from the former four triple bend achromatic (TBA). These different types of the insertion devices can greatly improve the performance of the light source, but simultaneously they can also influence the dynamics of the electron beam in the storage ring. Especially they can bring the distortion of the linear beam optics seriously. In order to make sure the stability and the quality of the beam meeting the design goal, the effect of these insertion devices must be compensated. In this paper, a direct compensation method is applied for the wiggler in the HLSII storage ring with the particle swarm optimization.  
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THPMB024 Error Analysis for the Lattice of FELiChEM 3278
 
  • S. Huang, Z.G. He, W. Xu, S.C. Zhang, T. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  FELiChEM is a new experimental facility under construction at University of Science and Technology of China (USTC).The facility consists of the middle-infrared (MID-FEL) beam line for 2.5-50 um and the Far-infrared (FAR-FEL) beam line for 40-200um. To achieve the design FEL performance of IR-FEL, the beam with 30 mm-mrad emittance, 5 ps rms length and 1nC bunch charge is required. We conduct error analysis in order to evaluate the tolerances of machine parameters and alignments. In this paper, we simulate the orbit corrections and emittance growth under exist of misalignments and strength errors of magnets. The simulation results show that the trajectory errors can be corrected to mm levels in the whole lattice and the emittance increase is acceptable. At the entrance of undulator, the position and angular errors can be corrected very well. So the trajectory can be controlled in the undulator to meet the requirement of FEL.  
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THPMB027 Beam Transport Line of the LPA-FEL Facility Based on Transverse Gradient Undulator 3287
 
  • T. Liu, B. Liu, D. Wang, T. Zhang
    SINAP, Shanghai, People's Republic of China
  • Z. Huang
    SLAC, Menlo Park, California, USA
  • J.S. Liu
    Shanghai Institute of Optics and Fine Mechanics, Shanghai, People's Republic of China
 
  Free electron lasers (FELs) based on Laser Plasma Accelerators (LPAs) present a main research direction for achieving next generation compact advanced light sources. There are several major challenges of the LPA beam to generate high-brilliance FEL radiation including the large initial angular divergence and the large energy spread. Based on the LPA facility in SIOM that has successfully obtained quasi-monochromatic beam with the central energy of hundreds of MeV, a specific design of a beam transport line is proposed to realize FEL gain using Transverse Gradient Undulator to compensate the relatively large beam energy spread. This beamline uses a single dipole, several strong focusing quadrupoles and correcting sextupoles to match proper beta functions and linear dispersion from the LPA beam to FEL radiation. The corresponding experimental facility of LPA-FEL in SIOM has been set up and will perform first tests to generate FEL radiation.  
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THPMB028 Beam Optics of 180-degree Bending Section including a Charge Stripper 3291
 
  • J.-H. Jang, H. Jin, J. Song
    IBS, Daejeon, Republic of Korea
 
  Funding: This work was supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea.
The linac of RISP (Rare Isotope Science Project) includes a charge stripper to obtain better acceleration efficiency. It is located after the lower energy part of the superconducting linac which accelerates 2 charge states, 33 and 34 of uranium beams to about 18 MeV/u. After the charge stripper, 5 charge states around 79 are selected and transported into the higher energy part of the linac through a 180-degree bending section. This work focused on the charge stripper effects on the beam optics in the bending section.
 
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THPMB029 Simultaneous Two Beam Acceleration Lattice Design Study for the Post Linear Accelerator of RISP 3294
 
  • S.W. Jang
    KNU, Deagu, Republic of Korea
  • E.-S. Kim
    Korea University Sejong Campus, Sejong, Republic of Korea
 
  The Rare Isotope Science Project, RISP, is the research complex by using heavy ion accelerator, which RISP research complex consists of front-end system, super conducting linear accelerator(SCL), ISOL system, In-fight system. The original purpose of post linear accelerator was for the alternative acceleration of stable driver beam from ECR ion source and unstable rare isotope beam from ISOL system. The new concept of acceleration method by using post accelerator lattice was studied to get more benefits. The idea was the simultaneous acceleration of stable driver beam and RI beam by using the average A/q value of post accelerator lattice. For the simultaneous two beam acceleration study, we used two ion beams the first one was 58Ni+8 and the other one was 132Sn+20. The beam dynamics simulation was performed by TRACK and TraceWin codes. In this poster, we will describe the results of beam dynamics study for the simultaneous two beam acceleration of the post linear accelerator of RISP.  
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THPMB030 Operation Improvement by Tuning of Storage Ring at PLS-II 3297
 
  • I. Hwang, M. Kim, T.-Y. Lee, C.D. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  After upgrade of the pohang light source (PLS-II), several problems reduced the quality of the top-up operation. Unbalance of the injection kicker system and it's lack of control had limited the efficiency of the injection from the linac to the storage ring. We tuned the storage ring to improve the injection efficiency and to stabilize the orbit during the injection.  
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THPMB032 Design Study and Multi-particle Tracking Simulation of the IH-DTL with KONUS Beam Dynamics for KHIMA Project 3299
 
  • Y. Lee, E.-S. Kim
    Korea University Sejong Campus, Sejong, Republic of Korea
  • G. Hahn
    KIRAMS, Seoul, Republic of Korea
  • Z. Li
    SCU, Chengdu, People's Republic of China
 
  The Korea Heavy Ion Medical Accelerator (KHIMA) project of the Korea Institute of Radiological and Medical Sciences (KIRAMS) has developed heavy ion medical accelerator. The injector system of the accelerator for the KHIMA project is composed of a low energy beam transport line (LEBT), radio frequency quadrupole (RFQ), interdigit H-mode drift tube linac (IH-DTL), and medium energy beam transport line (MEBT). The IH-DTL is designed with KONUS beam dynamics, and KONUS indicates a combined 0˚ structure. Optimization aims are to increase the quality of the beam and to reduce the beam loss. KONUS beam dynamics design and multi-particle tracking simulations of the IH-DTL with LORASR and TraceWIN code are performed.  
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THPMB033 Beam Tracking on the High Energy Beam Transport Line in KHIMA Medical Machine 3302
 
  • C.W. Park
    KIRAMS/KHIMA, Seoul, Republic of Korea
  • D.H. An, H. Yim
    KIRAMS, Seoul, Republic of Korea
 
  The Korea Heavy Ion Medical Accelerator (KHIMA) launched the synchrotron based hadron beam therapy facility for combined medical cancer treatment and cancer related research. The Korea Institute of Radiological & Medical Sciences (KIRAMS) synchrotron system has been designed to accelerate the particle beams having the kinetic energy interval of 60-230 MeV proton and 110-430 MeV/u carbon ions respectively. An accelerated beam from the synchrotron is transported to the patient position through the High Energy Beam Transport (HEBT) lines. In the HEBT lines, the lattice was designed with beam optics codes. In order to check and confirm the beam loss at the HEBT lines, the tracking code, TRACK, has been used with encoded field map and also with simulated field map by Opera3D code. The performances are described and also compared with two methods for manufacturing the components in the HEBT lines.  
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THPMB034 Short Bunch Operation Mode Development at the Synchrotron Radiation Source Siberia-2 3305
 
  • Y.A. Fomin, V. Korchuganov, S.I. Tomin, A.G. Valentinov
    NRC, Moscow, Russia
 
  Decrease of the electron bunch length gives rise to coherent synchrotron radiation in the THz spectral region. Also, the short photons pulse could provide an option for time-resolved processes studies. Currently the possibility to operate with short electron bunch of the synchrotron radiation source Siberia-2 is under consideration for this purpose. In the report the techniques of electron bunch shortening are described as well as the requirements are given for the parameters of the electron bunch and lattice. The authors present a modified lattice for the synchrotron radiation source Siberia-2 with low momentum compaction factor and the results of the beam dynamics studies.  
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THPMB035 A Comparative Study of Low Energy Compact Storage Rings for a Thomson Scattering X-ray Source 3308
 
  • L. Ovchinnikova, V.I. Shvedunov
    SINP MSU, Moscow, Russia
  • E.G. Bessonov, M.V. Gorbunkov
    LPI, Moscow, Russia
  • A.A. Mikhailichenko
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • V.I. Shvedunov
    LEA MSU, Moscow, Russia
 
  A low-energy (<50 MeV) compact storage ring is a basic component of an X-ray source with high average flux based on Thomson scattering. Such ring provides electron bunches with ~1 nC charge and repetition rate up to 100 MHz for interaction with intense laser pulses. Such ring should provide a small (tens of microns rms) beam radius at interaction point, must have large dynamic aperture, sufficient space for allocation of different elements, such as laser resonator, RF cavity, fast beam injection/extraction systems, beam pick-ups and correctors. In this report, we present the results of comparative study of four versions of storage ring with different structure of lattices.  
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THPMB036 Model­-Dependent Accelerator Lattice Fit Based on BPM Data and Generating Functions 3311
 
  • Yu. Maltseva, I.A. Morozov
    BINP SB RAS, Novosibirsk, Russia
 
  Obtaining accurate linear and nonlinear accelerator models is critical for routine accelerator operation. Here we consider a method based on BPM data and generating functions that provides fitted accelerator model. Using measurements from at least three BPMs and generating functions between them allows obtaining momenta at BPMs as the functions of model parameters and comparing them. Thus, lattice parameters can be fitted. Theoretical results are presented and the method is applied to the model examples.  
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THPMB037 Comparing the Transverse Dynamics of the ESS Linac Simulator and the Spallation Neutron Source Linac 3314
 
  • E. Laface, Y.I. Levinsen
    ESS, Lund, Sweden
  • T.A. Pelaia II
    ORNL, Oak Ridge, Tennessee, USA
 
  The ESS Linac Simulator (ELS) is the model that will be used at the European Spallation Source ERIC in Lund, Sweden, to simulate the transport of the beam envelope during operations. On August 12th 2015, we had the opportunity to use two hours of beam time in the linac of the Spallation Neutron Source in Oak Ridge to benchmark ELS. In this paper we present the results of the transverse dynamics measurements. Such measurements are obtained upon kicking the beam in the medium-energy beam transport (MEBT) and measuring the effect of the oscillation of the beam centroid in 58 beam position monitors (BPMs). The ELS model and these measurements are in agreement with an average discrepancy of 4% in the superconducting section of the accelerator.  
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THPMB038 Comparing RF-Cavity Phase-Scan Simulations in the ESS Linac Simulator with Measurements Taken in the Spallation Neutron Source Coupled-Cavity Linac 3317
 
  • E. Laface, Y.I. Levinsen
    ESS, Lund, Sweden
  • I. List
    Cosylab, Ljubljana, Slovenia
  • T.A. Pelaia II
    ORNL, Oak Ridge, Tennessee, USA
 
  The ESS Linac Simulator (ELS) is the model that will be used at the European Spallation Source ERIC in Lund, Sweden, to simulate the transport of the beam envelope for the operations. During the machine restart in August 2015 at the Spallation Neutron Source (SNS) in Oak Ridge, USA, we were able to perform the first benchmarking studies of the ELS. In this paper, we present the results of the phase-scans performed in four RF cavities of the coupled-cavity linac at SNS compared with the same scans simulated in the ELS. The phase of the cavity was modified while the phase of the beam was recorded in two BPMs downstream from the cavity. This measurement was repeated for four independent cavities and the results are compared here with the model, which favourably reproduces the BPM response to the cavity scans.  
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THPMB039 Voltage Error Studies in the ESS RFQ 3320
 
  • A. Ponton, Y.I. Levinsen, E. Sargsyan
    ESS, Lund, Sweden
  • A.C. France, O. Piquet, B. Pottin
    CEA/IRFU, Gif-sur-Yvette, France
 
  During the fabrication of an RFQ, deviation from the perfect geometry will occur during assembling, brazing and machining the different parts. These geometrical defects will impact the theoretical inter-vane voltage, given by the beam dynamics, by altering the quadrupolar component as well as adding dipolar terms in the voltage function. Tuners can correct partially the effect of the manufacturing. The study summarizes the effects of the voltage errors on the beam quality in the case of the ESS RFQ with a harmonic analysis of the voltage function. We discuss the acceptable level of voltage errors and associated mechanical tolerances.  
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THPMB040 Charged Particle Transport, Gaussian Optics, Error Propagation: It's all the Same 3324
 
  • V.G. Ziemann
    Uppsala University, Uppsala, Sweden
 
  We derive a correspondence between the parameters used in Gaussian light beam propagation with wavelength, beam size, and wave front curvature to the description in terms of emittance and Twiss parameters commonly used in charged particle optics. Furthermore, we discuss the analogy of transporting beams to the propagation of measurement uncertainties.  
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THPMB041 Optics-measurement-based BPM Calibration 3328
SUPSS047   use link to see paper's listing under its alternate paper code  
 
  • A. Garcia-Tabares, F.S. Carlier, J.M. Coello de Portugal, A. Langner, E.H. Maclean, L. Malina, T. Persson, P.K. Skowroński, M. Solfaroli Camillocci, R. Tomás
    CERN, Geneva, Switzerland
 
  The LHC beta functions (β) can be measured using the phase or the amplitude of betatron oscillations obtained with beam position monitors (BPMs). Using the amplitude information results in a β measurement affected by BPM calibration. This work aims at calibrating BPMs using optics measurements. For this, βs from amplitude and phase and normalized dispersion obtained from many different measurements in 2015 with different optics and corrections are analyzed. Simulations are also performed to support the analyses.  
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THPMB042 Residual Orbit Correction Studies for the FCC-hh 3332
 
  • D. Boutin, B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Chancé, J. Payet
    CEA/DSM/IRFU, France
  • B.J. Holzer, R. Martin, D. Schulte
    CERN, Geneva, Switzerland
 
  The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the three options considered for the next genera-tion accelerator in high-energy physics as recommended by the European Strategy Group [*]. Preliminary studies have started to estimate the design parameters of FCC-hh. One of these studies is the calculation of the residual orbit in the arcs of the collider. This is very important for the evaluation of the alignment tolerances of the quadru-poles used in the arcs, the dimensioning of the correctors and of the beam screen. Moreover it has an impact on the dynamic aperture of the ring and the field tolerances of the arc multipoles. To perform the simulations, the beam transport code MADX has been used. Systematic studies of the residual orbit and of the correctors' strength de-pendence on the magnets misalignment or field errors are presented and discussed.
[*] A. Ball et al., EDMS-0134202.
 
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THPMB043 Progress in Ultra-Low β* Study at ATF2 3335
 
  • M. Patecki, D.R. Bett, F. Plassard, R. Tomás
    CERN, Geneva, Switzerland
  • K. Kubo, S. Kuroda, T. Naito, T. Okugi, T. Tauchi, N. Terunuma
    KEK, Ibaraki, Japan
  • M. Patecki
    Warsaw University of Technology, Warsaw, Poland
  • T. Tauchi, N. Terunuma
    Sokendai, Ibaraki, Japan
 
  A nanometer beam size in the interaction point (IP) is required in case of future linear colliders for achieving the desired rate of particle collisions. KEK Accelerator Test Facility (ATF2), a scaled down implementation of the beam delivery system (BDS), serves for investigating the limits of electron beam focusing at the interaction point. The goal of the ultra-low beta∗ study is to lower the IP vertical beam size by lowering the betay∗ value while keeping the betax∗ value unchanged. Good control over the beam optics is therefore required. The first experience with low beta∗ optics revealed a mismatch between the optics designed in the model with respect to the beam parameters observed in the experiment. Additionally, existing methods of beam parameters characterization at the IP were biased with high uncertainties making it difficult to set the desired optics. In this paper we report on the new method introduced in ATF2 for IP beam parameters characterization which gives a good control over the applied optics and makes the ultra-low beta∗ study possible to conduct. It can be also used for verifying the performance of some of the existing beam instrumentation devices.  
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THPMB044 Limitations on Optics Measurements in the LHC 3339
 
  • P.K. Skowroński, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, A. Langner, E.H. Maclean, L. Malina, M. McAteer, T. Persson, R. Tomás
    CERN, Geneva, Switzerland
  • A. Langner
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • L. Malina
    University of Oslo, Oslo, Norway
 
  In preparation of the optics commissioning at an energy of 6.5 TeV, many improvements have been done to cope with the expected reduced signal to noise ratio due to lowered bunch intensities imposed by machine protection considerations. This included, among others, an increase of the flat top duration of the AC dipole excitations, which allowed to use more turn-by-turn data for the analysis. The longer data acquisition revealed slow drifts of the optics, which limited the increased measurement precision. Furthermore, we will present how orbit drifts influenced dispersion measurements and, as a consequence, posed another limitation for the optics correction. In this paper we will discuss the implications of these observations for the measurement and correction of the optics.  
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THPMB045 Comparison of Optics Measurement Methods in ESRF 3343
 
  • L. Malina, J.M. Coello de Portugal, A. Langner, T. Persson, P.K. Skowroński, R. Tomás
    CERN, Geneva, Switzerland
  • L. Farvacque, A. Franchi
    ESRF, Grenoble, France
 
  The N-BPM and the Amplitude methods, which are used in the LHC for beam optics measurement, were applied to the ESRF storage ring. We compare the results to the Orbit Response Matrix (ORM) method that is routinely used in the ESRF. These techniques are conceptually different since the ORM is based on the orbit response upon strength variation of steering magnets while the LHC techniques rely on the harmonic analysis of turn-by-turn position excited by a kicker or an AC dipole. Finally, we compare these methods and show the differences in their performance in the ESRF environment.  
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THPMB047 Beam Dynamics Studies of the ELENA Electrostatic Transfer Lines in the Presence of Magnetic Stray Fields 3351
 
  • J. Jentzsch, W. Bartmann, M.A. Fraser, R. Ostojić, G. Tranquille
    CERN, Geneva, Switzerland
  • D. Barna
    University of Tokyo, Tokyo, Japan
 
  The ELENA (Extra Low ENergy Antiproton) ring at CERN will further decelerate antiprotons produced at the AD (Antiproton Decelerator) facility from a kinetic energy of 5.3 MeV to 100 keV. The antiprotons will be distributed through a network of electrostatic transfer lines to several experiments, which will replace the existing magnetic transfer lines. The existing experiments and limited space in the AD hall forces the new transfer lines into close proximity to the high-field solenoids used by some experiments to trap the antiprotons. The stray fields from the experimental magnets are known to perturb beam delivery and are a concern for operation at the decreased beam rigidity provided by ELENA. A study was carried out to investigate the influence of stray magnetic fields on the beam, including different ramping periods and operational scenarios. The analytical model of the fields used for simulation will be discussed. Furthermore, trajectory correction algorithms using MADX optic model of the lines have been investigated. The results of these studies as well as specifications of acceptable stray field limits and field attenuation requirements will be presented.  
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THPMB048 Design and Optimisation of the ELENA Electron Cooler Gun and Collector 3354
 
  • G. Tranquille, J. Cenede
    CERN, Geneva, Switzerland
 
  Phase space compression of the antiproton beam in ELENA will be performed by a new electron cooler. The performance of the cooler is greatly influenced by the properties of the electron beam. Careful design of the electron gun electrodes, the quality of the guiding magnetic field and the efficient recuperation of the electrons in the collector ensure that the cooler performance is optimal. We have used COMSOL Multiphysics to design and optimise the complete electron cooler with particular attention to the gun and collector. This software suite uses physics interfaces for modelling common applications and then allows the user to combine the different interfaces in one multi-physics simulation.  
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THPMB049 Optics Calibration During Commissioning of the Taiwan Photon Source 3357
 
  • F.H. Tseng, C.H. Chen, J.Y. Chen, M.-S. Chiu, C.-C. Kuo, Y.-C. Liu, H.-J. Tsai
    NSRRC, Hsinchu, Taiwan
 
  The Taiwan Photon Source is a 3-GeV low emittance synchrotron light machine with circumference of 518.4m. The lattice is with 24-cell DBA structure and emittance is 1.6 nm-rad. During the commissioning in the past year, we employed MATLAB-based high level applications to calibrate the optical functions in three different operation lattice modes. In particular, we used LOCO (Linear Optics from Closed Orbit) to restore the machine optical functions and reduce emittance coupling ratio. The beam-based alignment (BBA) measurements as well as BPM and corrector errors were identified.  
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THPMB052 Studies on Electron Beam Injector System for Linac-based Coherent Thz Source in Thailand 3366
SUPSS051   use link to see paper's listing under its alternate paper code  
 
  • W. Thongpakdi, S. Rimjaem
    Chiang Mai University, Chiang Mai, Thailand
 
  Funding: The Department of Physics and Materials Science, Faculty of Science, Chiang Mai University and the Development and Promotion of Science and Technology Talents Project (DPST).
At the Plasma and Beam Physics Research Facility, Chiang Mai University, a thermionic cathode RF electron gun and alpha magnet are used together as an injector system for a linac-based THz source. Investigate the optimal performance of the injector system, beam dynamic simulations are performed by computer codes PARMELA, ASTRA and ELEGANT. The input 3D field distributions of the RF-gun for PARMELA and ASTRA simulations are obtained from the RF modeling program CST Microwave Studio. The beam transport calculation using the program ELEGANT is performed to study behavior of electrons from the gun exit through the alpha magnet, a travelling wave linac, magnet elements, drift tubes, and related beam diagnostic components. Energy slits inside the alpha magnet vacuum chamber is used to select electrons with desired kinetic energies. The alpha magnet compresses electron bunches with certain bunch length before the beam entering the linac to obtain minimum energy spread and shortest bunch length at the experimental station. Results of electron beam optimization with appropriated conditions for generation of intense coherent THz radiation will be reported and discussed in this contribution.
This work has been supported by the CMU Junior Research Fellowship Program, the Department of Physics and Materials Science, Faculty of Science, Chiang Mai University and DPST.
 
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THPMB053 nuSTORM FFAG Decay Ring 3369
 
  • J.-B. Lagrange, J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • R.B. Appleby, J.M. Garland, H.L. Owen, S.C. Tygier
    UMAN, Manchester, United Kingdom
  • R.B. Appleby
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.D. Bross, A. Liu
    Fermilab, Batavia, Illinois, USA
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
 
  The neutrino beam produced from muons decaying in a storage ring would be an ideal tool for precise neutrino cross section measurements and search for sterile neutrinos due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a racetrack storage ring, where circulating muon beam would be captured. The storage ring has two options: a FODO solution with large aperture quadrupoles and a racetrack FFAG (Fixed Field Alternating Gradient) using the recent developments in FFAGs. Machine parameters, linear optics design and beam dynamics are discussed in this paper.  
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THPMB054 FFAG Beam Line for nuPIL - Neutrinos from PIon Beam Line 3372
 
  • J.-B. Lagrange, J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • R.B. Appleby, S.C. Tygier
    UMAN, Manchester, United Kingdom
  • R.B. Appleby
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A.D. Bross, A. Liu
    Fermilab, Batavia, Illinois, USA
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
 
  The Long Baseline Neutrino Facilities (LBNF) program aims to deliver a neutrino beam for the Deep Underground Neutrino Experiment (DUNE). The current baseline for LBNF is a conventional magnetic horn and decay pipe system. Neutrinos from PIon beam Line (nuPIL) is a part of the optimization effort to optimize the LBNF. It consists of a pion beam line after the horn to clean the beam of high energy protons and wrong-sign pions before transporting them into a decay beam line, where instrumentation could be implemented. This paper focuses on the FFAG solution for this pion beam line. The resulting neutrino flux is also presented.  
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THPMB055 A FODO Beam Line Design for nuPIL 3375
 
  • A. Liu, A.D. Bross
    Fermilab, Batavia, Illinois, USA
  • J.-B. Lagrange
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Funding: Fermi National Accelerator Laboratory
The Fermilab Deep Underground Neutrino Experiment (DUNE) was proposed to determine the neutrino mass hierarchy and demonstrate leptonic CP violation. The current design of the facility that produces the neutrino beam (LBNF) uses magnetic horns to collect pions and a decay pipe to allow them to decay. In this paper, a design of a possible alternative for the conventional neutrino beam in LBNF is presented. In this design, a FODO magnet beam line is used to collect the pions from the downstream face of a horn, bend them by  ∼ 5.8 degrees and then transport them in a straight beam line where they decay to produce neutrinos. The idea of using neutrinos from the PIon beam Line (nuPIL) provides flavor-pure neutrino beams that can be well understood by implementing standard beam measurement technology. The neutrino flux and the resulting δCP sensitivity from the FODO nuPIL are also presented in the paper.
 
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THPMB056 Witness Beam Production with an RF Gun and a Travelling Wave Booster Linac for AWAKE Experiment at CERN 3378
 
  • O. Mete Apsimon, G.X. Xia
    UMAN, Manchester, United Kingdom
  • R. Apsimon, G. Burt
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • S. Döbert
    CERN, Geneva, Switzerland
 
  Funding: This work is supported by the Cockcroft Institute Core Grant and STFC.
AWAKE is a unique experiment that aims to demonstrate the proton driven plasma wakefield acceleration. In this experiment, proton bunches from the SPS accelerator will be injected into a 10m long pre-formed plasma section to form wakefields of hundreds MV/m to several GV/m. A second beam, e.g., the witness beam, will be injected after the protons in an appropriate phase to gain energy from the wakefields. A photo-injector will be utilised to deliver this second beam. It consists of an S-band RF gun followed by a meter long accelerating travelling wave structure (ATS). The RF gun was recuperated from existing PHIN photo-injector. A 3D RF design of the ATS was done by using the CST code and the field maps produced were used to characterise the electron beam dynamics under space charge effect by using the PARMELA code. The impact of the mechanical errors on the beam dynamics were investigated.
 
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THPMR001 Online Suppression of the Sextupole Resonance Driving Terms in the Diamond Storage Ring 3381
 
  • I.P.S. Martin, M. Apollonio, R. Bartolini
    DLS, Oxfordshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
 
  Suppression of the sextupole resonance driving terms (RDTs) is a widely used technique for optimising the theoretical on and off-momentum dynamic aperture for electron storage rings. Recently, this technique was applied online to the Diamond storage ring, with suppression of individual RDTs achieved via a sextupole family to RDT response matrix*. In this paper we present recent studies of the method, in which the ability to improve the lifetime and injection efficiency are investigated. An extension of the technique is investigated by combining it with the Robust Conjugate Direction Search (RCDS) optimisation algorithm**.
*J. Bengtsson, et al., Phys. Rev. ST Accel. Beams 18, 074002, (2015).
**X. Huang, et al., Nucl. Instrum. Methods Phys. Res. Sect. A 726, 77, (2013).
 
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THPMR002 Optics Corrections with LOCO in the Fermilab Booster 3385
 
  • C.-Y. Tan, L.R. Prost, K. Seiya, A.K. Triplett
    Fermilab, Batavia, Illinois, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The optics of the Fermilab Booster has been corrected with LOCO (Linear Optics from Closed Orbits). However, the first corrections did not show any improvement in capture efficiency at injection. A detailed analysis of the results showed that the problem lay in the MADX optics file. Both the quadrupole and chromatic strengths were originally set as constants independent of beam energy. However, careful comparison between the measured and calculated tunes and chromatcity show that these strengths are energy dependent. After the MADX model was modified with these new energy dependent strengths, the LOCO corrected lattice has been applied to Booster. The effect of the corrected lattice will be discussed here.
 
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THPMR003 Failure Modes and Beam Losses Studies in ILC Bunch Compressors and Main Linac 3388
 
  • A. Saini, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, Illinois, USA
 
  Proposed International linear collider (ILC) involves high average beam power. Dealing with high average beam power and smaller beam sizes result in stringent tolerances on beam losses and therefore, extensive studies are required to investigate every possible scenarios that lead to beam losses. In this paper we discuss beam losses due to failure of critical elements in beamline for ILC bunch compressors and main linac.  
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THPMR004 Design of a Compact ion Beam Transport System for the BELLA Ion Accelerator 3391
 
  • Q. Ji, S.S. Bulanov, E. Esarey, W. Leemans, T. Schenkel, S. Steinke
    LBNL, Berkeley, California, USA
 
  Funding: This work was supported by LDRD funding from Lawrence Berkeley National Lab, provided by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Berkeley Lab Laser Accelerator (BELLA) Center hosts a Ti:sapphire CPA laser providing laser pulses at petawatt-level peak power with a repetition rate of 1 Hz. High irradiances of 1022 W/cm2 can be achieved with a short focal length beamline when the laser is focused to a spot of w0 < 5 um. Under this condition, theoretical and particle-in-cell (PIC) simulations have shown that protons and helium ions at energies up to several hundred MeV/u can be expected from the interaction between BELLA laser pulses and different targets. High ion energies*, low energy spread with high controllability and stability, a new generation of ion accelerators using high performance laser-driven ion beam has numerous potential applications such as injectors for conventional accelerators, radiation therapy, as well as high energy density laboratory physics and material science studies. We will present a preliminary ion optics design to collect, transport, and focus the ions generated from the laser-driven ion accelerator, and beam dynamics results using the ion distribution from the PIC simulation.
* S.S. Bulanov et al, Physical Review Special Topics: Accelerators and Beams 18, 061302 (2015).
 
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THPMR005 Systematic Errors Investigation in Frozen and Quasi-Frozen Spin Lattices of Deuteron EDM Ring 3394
 
  • V. Senichev, B. Lorentz
    FZJ, Jülich, Germany
  • S.N. Andrianov, A.N. Ivanov
    St. Petersburg State University, St. Petersburg, Russia
  • M. Berz, E. Valetov
    MSU, East Lansing, Michigan, USA
  • S. Chekmenev, J. Pretz
    RWTH, Aachen, Germany
 
  The search for the electric dipole moment (EDM) in the storage ring raises two questions: how to create conditions for maximum growth of the total EDM signal of all particles in bunch, and how to differentiate the EDM signal from the induced magnetic dipole moment (MDM) signal. The T-BMT equation distinctly addresses each issue. Because the EDM signal is proportional to the projection of the spin on the direction of the momentum, it is desirable to freeze the spin direction of all particles in a bunch along momentum. It can be successfully implemented in the Quasi Frozen (QFS) and Frozen (FS) Spin structures. However, in case of magnet misalignments, the induced MDM signal may arise in the same plane as the EDM signal and thereby prevent its registration. In this paper, we analyze the effect of errors together with the spin-tune decoherence of all particles in the bunch for FS and QFS options.  
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THPMR008 Experimental Crosscheck of Algorithms for Magnet Lattice Correction 3400
 
  • V.V. Smaluk, W. Guo, Y. Hidaka, Y. Li, G.M. Wang, L. Yang, X. Yang
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by DOE contract DE-AC02-98CH10886
Performance, capabilities and limitations of various algorithms for linear magnet optics correction have been studied experimentally at NSLS-II. For the crosscheck, we have selected 4 algorithms based on turn-by-turn beam position analysis: weighted correction of betatron phase and amplitude, independent component analysis, model-independent analysis, and driving-terms-based linear optics characterization. A LOCO algorithm based on closed orbit measurement has been used as a reference. For the correction, either iterative solving of linear problem (matrix inversion with singular-value decomposition) or variational optimization has been used. For all the algorithms, accuracy limitations and convergence of linear lattice correction are discussed.
 
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THPMR010 Electron Polarization in the eRHIC Ring-Ring Design 3403
 
  • V. Ptitsyn, C. Montag, S. Tepikian
    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.
High electron beam polarization (70-80%) is required in the future electron-ion collider eRHIC over the whole electron beam energy range from 5 GeV to 20 GeV. This paper analyzes important aspects for achieving a high electron polarization level in the ring-ring design option of eRHIC and presents the design of spin rotators required to generate the longitudinal polarization orientation at the interaction point. Experiment considerations require bunch spin patterns with both spins up and down. A highly polarized beam will be produced by a photo-injector, accelerated to full collision energy by an injector accelerator and injected into the storage ring. Beam depolarization time in the storage ring has to be minimized in the presence of spin rotators, detector solenoid and damping wiggler, which establishes specific requirements for the ring lattice.
 
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THPMR013 A New Optics for Sirius 3413
 
  • L. Liu, X.R. Resende, F. H. de Sá
    LNLS, Campinas, Brazil
 
  We report on the latest optics modifications for the 3 GeV Sirius electron storage ring presently under construction at the Brazilian Synchrotron Light Laboratory, LNLS. Although the basic parameters are set and frozen, improvements in the magnetic lattice and beam optics are still being implemented. In particular, the central dipole in the 5BA cell has been replaced by an all-permanent-magnet dipole with a thin superbend in the center with peak magnetic field of 3.2 T and the operation mode has now symmetry 5, with 15 low βx straight sections and 5 high βx sections. The 3 GeV ring bare lattice emittance is now 0.25 nm.rad.  
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THPMR016 Horizontal Phase Space Shaping for Optimized Off-axis Injection Efficiency 3424
 
  • S.M. White, S. Lagarde, S.M. Liuzzo, B. Ogier, T.P. Perron, P. Raimondi
    ESRF, Grenoble, France
 
  With the introduction of top-up operation at the ESRF it becomes important to reduce as much as possible any kind of perturbation seen by the users during injection. For this purpose, a novel technique to improve injection efficiency by shaping the horizontal beam phase space to better match the storage ring acceptance and hence reduce the duration of injections was developed. Theoretical concept, simulations and first experimental results are presented.  
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THPMR040 Local Optics Corrections in the HL-LHC IR 3480
SUPSS046   use link to see paper's listing under its alternate paper code  
 
  • J.M. Coello de Portugal, F.S. Carlier, A. Garcia-Tabares, A. Langner, E.H. Maclean, L. Malina, T. Persson, P.K. Skowroński, R. Tomás
    CERN, Geneva, Switzerland
 
  For the high luminosity upgrade of the LHC optics correction in the interaction regions is expected to be challenged by the very low β* and the sizable expected quadrupolar errors in the triplet. This paper addresses the performance and limitations of the segment-by-segment technique to correct quadrupolar and skew quadrupolar errors in the HL-LHC IR via computer simulations. Required improvements to this technique and possible combinations with other correction approaches are also presented including experimental tests in the current LHC IR.  
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THPMR046 Advanced BBA Techniques for the Final Focuses of Future Linear Colliders 3504
 
  • J. Snuverink, A. Latina, D. Schulte, R. Tomás
    CERN, Geneva, Switzerland
  • R.M. Bodenstein
    JAI, Oxford, United Kingdom
 
  Tuning the Final-Focus System of future linear colliders is one of the open challenges the linear collider community is undertaking. Future colliders like ILC and CLIC will feature complex lattice design to focus the beams to nanometer level at the Interaction Point. Standard Beam-Based Alignment (BBA) techniques have proven to hardly meet the requirements in terms of acceptable emittance growth, in both machines. A set of new techniques, respectively called: nonlinear Dispersion-Free Steering (DFS), DFS-knobs scan, and hybrid DFS-knobs with beamsize measurements, have been put in place to cope with the challenge. This paper will reveal the key ideas behind the new techniques, and compare their effectiveness w.r.t. the conventional BBA tuning procedures.  
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THPMR047 Two-beam Tuning in the CLIC BDS 3508
 
  • J. Snuverink, R.M. Bodenstein
    JAI, Egham, Surrey, United Kingdom
  • R. Tomás
    CERN, Geneva, Switzerland
 
  Beam tuning in the beam delivery system (BDS) is one of the major challenges for the future linear colliders. In those colliders, due to fast detuning of the final focus optics both beamlines will need to be tuned simultaneously. An initial two-beam tuning study for the Compact Linear Collider (CLIC) BDS had been performed, but was not fully satisfactory. In this paper a more extensive study is presented, as well as several improvements to the tuning algorithm. A comparative study between two competing CLIC final focus systems (FFS), the traditional and the compact FFS, will be discussed.  
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THPOR002 Chromaticity Compensation Schemes for the Arc Lattice of the FCC-ee Collider 3763
SUPSS048   use link to see paper's listing under its alternate paper code  
 
  • B. Härer
    KIT, Karlsruhe, Germany
  • A. Doblhammer, B.J. Holzer
    CERN, Geneva, Switzerland
 
  FCC-ee is an 100 km e+/e collider that is being designed within the Future Circular Collider Study organised by CERN. It's layout is optimised for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1035 cm-2s-1. Extremely small vertical beta functions of 1 - 2 mm are required at the two interaction points to reach this goal. The strong focusing required in the final doublet quadrupoles drives the chromaticity to more than -2000 units, far beyond the values that had been achieved in previous storage rings. As a consequence a pure linear chromaticity compensation scheme will not be sufficient to obtain the required ± 2 % energy acceptance. A state of the art multi-family sextupole scheme will have to be combined with a local chromaticity correction. This paper presents the design of the arc lattice, optimised for highest momentum acceptance and the results of systematic studies of the sextupole scheme in the arcs in order to gain highest chromaticity performance.  
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THPOR003 Tapering Options and Emittance Fine Tuning for the FCC-ee Collider 3767
 
  • B. Härer, A. Doblhammer, B.J. Holzer
    CERN, Geneva, Switzerland
 
  The lepton collider version of the FCC study describes a future electron-positron collider with a circumference in the order of 100 km, optimised for operation with collision energies in the range of 90 GeV to 350 GeV (FCC- ee). This paper presents the layout of the machine and the constraints on the design of the arc lattice in the context of the four different beam energies that are foreseen for beam operation. Special emphasis is put on the compensation of the effect of the strong synchrotron radiation losses. The beam orbit as well as the optics have to be re-optimised for a given operation energy in order to achieve the foreseen emittance of ε = 1 nm in the horizontal and 1 pm in the vertical plane. Counter measures of the so-called saw-tooth effect of the design orbit are needed as well as a compensation of the energy loss on the beam optics. The paper summarizes different scenarios of how to achieve this goal as well as the need for additional emittance fine tuning using wiggler magnets.  
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THPOR054 Analysis of the SPS Long Term Orbit Drifts 3914
 
  • F.M. Velotti, C. Bracco, K. Cornelis, L.N. Drøsdal, M.A. Fraser, B. Goddard, V. Kain, M. Meddahi
    CERN, Geneva, Switzerland
  • E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois, USA
 
  The Super Proton Synchrotron (SPS) is the last accelerator in the Large Hadron Collider (LHC) injector chain, and has to deliver the two high-intensity 450 GeV proton beams to the LHC. The transport from SPS to LHC is done through the two Transfer Lines (TL), TI2 and TI8, for Beam 1 (B1) and Beam 2 (B2) respectively. During the first LHC operation period Run 1, a long term drift of the SPS orbit was observed, causing changes in the LHC injection due to the resulting changes in the TL trajectories. This translated into longer LHC turnaround because of the necessity to periodically correct the TL trajectories in order to preserve the beam quality at injection into the LHC. Different sources for the SPS orbit drifts have been investigated: each of them can account only partially for the total orbit drift observed. In this paper, the possible sources of such drift are described, together with the simulated and measured effect they cause. Possible solutions and countermeasures are also discussed.  
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