Keyword: lattice
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MOA2CO03 Measurement of Tune Shift with Amplitude from BPM Data with a Single Kicker Pulse ion, kicker, feedback, experiment 6

• Y. Hidaka, W.X. Cheng, B. Podobedov
BNL, Upton, Long Island, New York, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-AC02-98CH10886.
Measurements of amplitude-dependent tune shift are critical for understanding of nonlinear single particle dynamics in storage rings. The conventional method involves scanning of the kicker amplitude while having a short bunch train at the top of the kicker pulse. In this paper we present a novel, alternative technique that uses a long continuous bunch train, or a sequence of bunch trains, that are spread along the ring, such that different bunches experience different kick amplitudes with a single shot of a kicker pulse. With these beams, a curve of tune shift with amplitude can be extracted from the recently added new NSLS-II BPM feature called gated turn-by-turn (TbT) BPM data that can resolve bunches within a turn, either alone or together with a bunch-by-bunch BPM data. This technique is immune to pulse-to-pulse jitters and long-term machine drift.

Slides MOA2CO03 [1.961 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOA2CO03
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TUB2IO01 Accelerator Physics Challenges in the Design of Multi Bend Achromat Based Storage Rings ion, emittance, storage-ring, injection 278

• M. Borland
ANL, Argonne, Illinois, USA
• R.O. Hettel
SLAC, Menlo Park, California, USA
• S.C. Leemann
MAX IV Laboratory, Lund University, Lund, Sweden
• D. Robin
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
With the recent success in commissioning of MAX IV, the multi-bend achromat (MBA) lattice has begun to deliver on its promise to usher in a new generation of higher-brightness synchrotron light sources. In this paper, we begin by reviewing the challenges, recent success, and lessons learned of the MAX-IV project. Drawing on these lessons, we then describe the physics challenges in even more ambitious rings and how these can be met. In addition, we touch on engineering issues and choices that are tightly linked with the physics design.

Slides TUB2IO01 [3.723 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB2IO01
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TUPOA58 Minimization of Emittance at the Cornell Electron Storage Ring With Sloppy Models ion, emittance, simulation, storage-ring 402

• W.F. Bergan, A.C. Bartnik, I.V. Bazarov, H. He, D. L. Rubin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
• J.P. Sethna
Cornell University, Ithaca, New York, USA

Funding: DOE DE-SC0013571 NSF DGE-1144153
Our current method to minimize the vertical emittance of the beam at the Cornell Electron Storage Ring (CESR) involves measurement and correction of the dispersion, coupling, and orbit of the beam and lets us reach emittances of 10 pm, but is limited by finite dispersion measurement resolution.* For further improvement in the vertical emittance, we propose using a method based on the theory of sloppy models.** The storage ring lattice permits us to identify the dependence of the dispersion and emittance on our corrector magnets, and taking the singular value decomposition of the dispersion/corrector Jacobian gives us the combinations of these magnets which will be effective knobs for emittance tuning, ordered by singular value. These knobs will permit us to empirically tune the emittance based on direct measurements of the vertical beam size. Simulations show that when starting from a lattice with realistic alignment errors which has been corrected by our existing method to have an emittance of a few pm, this new method will enable us to reduce the emittance to nearly the quantum limit, assuming that vertical dispersion is the primary source of our residual emittance.
* J. Shanks, D.L. Rubin, and D. Sagan, Phys. Rev. ST Accel. Beams 17, 044003 (2014).
** K.S. Brown and J.P. Sethna, Phys. Rev. E 68, 021904 (2003).

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA58
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TUPOB11 Quantification of Octupole Magnets at the University of Maryland Electron Ring ion, octupole, quadrupole, multipole 503

• H. Baumgartner, B. Beaudoin, S. Bernal, I. Haber, T.W. Koeth, D.B. Matthew, K.J. Ruisard, M.R. Teperman
UMD, College Park, Maryland, USA

Funding: Funding for this project is provided by DOE-HEP and the NSF Accelerator Science Program
The intensity frontier is limited by the ability to propagate substantial amounts of beam current without resulting in particle scrapping and/or losses from resonant growth and halo formation. Modern accelerators are based on the theories developed in the 1950's that assume particle motion is bounded and subject to linear forces. Recent theoretical developments have demonstrated that a strongly nonlinear lattice can be used to stably transport an intense beam has resulted in a fundamental rethinking of the conventional wisdom. A lattice composed of strong nonlinear magnets is predicted by theory to damp resonances while maintaining dynamic aperture. Results of rotating coil measurements, magnetic field scans and simulations will be presented, quantifying the multi-pole moments and fringe fields in the 1st generation Printed Circuit Board (PCB) octupoles for UMER's nonlinear lattice experiments.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB11
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TUPOB12 Experimental Plans for Single-Channel Strong Octupole Fields at the University of Maryland Electron Ring ion, octupole, quadrupole, focusing 507

• K.J. Ruisard, H. Baumgartner, B. Beaudoin, I. Haber, T.W. Koeth, M.R. Teperman
UMD, College Park, Maryland, USA

Funding: Funding for this project and travel is provided by DOE-HEP, NSF GRFP and NSF Accelerator Science Program
Nonlinear quasi-integrable optics is a promising development on the horizon of high-intensity ring design. Large amplitude-dependent tune spreads, driven by strong nonlinear magnet inserts, lead to decoupling from incoherent tune resonances. This reduces intensity-driven beam loss while quasi-integrability ensures a well-contained beam. In this paper we discuss on-going work to install and interrogate a long-octupole channel at the University of Maryland Electron Ring (UMER). This is a discrete insert that occupies 20 degrees of the ring, consisting of independently powered printed circuit octupole magnets. Transverse confinement is obtained with quadrupoles external to this insert. Operating UMER as a non-FODO lattice, in order to meet the beam-envelope requirements of the quasi-integrable lattice, is a challenge. We discuss efforts to match the beam and optimize steering solutions. We also discuss our experiences operating a distributed strong octupole lattice.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB12
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TUPOB15 Implementing the Fast Multipole Boundary Element Method With High-Order Elements ion, multipole, simulation, controls 518

• A.J. Gee, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA

The next generation of beam applications will require high-intensity beams with unprecedented control. For the new system designs, simulations that model collective effects must achieve greater accuracies and scales than conventional methods allow. The fast multipole method is a strong candidate for modeling collective effects due to its linear scaling. It is well known the boundary effects become important for such intense beams. We implemented a constant element fast boundary element method (FMBEM) * as our first step in studying the boundary effects. To reduce the number of elements and discretization error, our next step is to allow for curvilinear elements. In this paper we will present our study on a quadratic and a cubic parametric method to model the surface.
* A.Gee and B.Erdelyi, "A Differential Algebraic Framework for the Fast Indirect Boundary Element Method," in Proc. IPAC'16. Busan, South Korea.

Poster TUPOB15 [1.727 MB]
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TUPOB26 Dynamics of Intense Beam in Quadrupole-Duodecapole Lattice Near Sixth Order Resonance ion, resonance, quadrupole, focusing 552

• Y.K. Batygin, T.T. Fronk
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by US DOE under contract DE-AC52-06NA25396
The presence of duodecapole components in quadrupole focusing field results in excitation of sixth-order single-particle resonance if the phase advance of the particles transverse oscillation is close to 60 deg. This phenomenon results in intensification of beam losses. We present analytical and numerical treatment of particle dynamics in the vicinity of sixth-order resonance. The topology of resonance in phase space is analyzed. Beam emittance growth due to crossing of resonance islands is determined. Halo formation of intense beams in presence of resonance conditions is examined.

Poster TUPOB26 [3.523 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB26
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TUPOB52 Linear Optics Characterization and Correction Method Using Turn-By-Turn BPM Data Based on Resonance Driving Terms with Simultaneous BPM Calibration Capability ion, coupling, experiment, quadrupole 605

• Y. Hidaka, B. Podobedov
BNL, Upton, Long Island, New York, USA
• J. Bengtsson
J B Optima, LLC, Rocky Point, USA

Funding: The study is supported by U.S. DOE under Contract No. DE-AC02-98CH10886.
A fast new linear lattice characterization / correction method based on turn-by-turn (TbT) beam position monitor (BPM) data in storage rings has been recently developed and experimentally demonstrated at NSLS-II. This method performs least-square fitting iteratively on the 4 frequency components extracted from TbT data and dispersion functions. The fitting parameters include the errors for normal/skew quadrupole strength and 4 types of BPM errors (gain, roll, and deformation). The computation of the Jacobian matrix for this system is very fast as it utilizes analytical expressions derived from the resonance driving terms (RDT), from which the method name DTBLOC (Driving-Terms-Based Linear Optics Characterization/Correction) originates. At NSLS-II, a lattice corrected with DTBLOC was estimated to have beta-beating of <1%, dispersion errors of ~1 mm, and emittance coupling ratio on the order of 10-4.

Poster TUPOB52 [2.206 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB52
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TUPOB54 Using Square Matrix to Realize Phase Space Manipulation and Dynamic Aperture Optimization ion, resonance, sextupole, dynamic-aperture 609

• Y. Li, L. Yu
BNL, Upton, Long Island, New York, USA

We introduce a new method of using square matrix to realize phase space manipulation and dynamic aperture optimization in storage rings. Both the tracking simulation and the experimental observation in the NSLS-II ring lattice are presented.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB54
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TUPOB55 Optimize the Algorithm for the Global Orbit Feedback at Fixed Energies and During Acceleration in RHIC ion, feedback, acceleration, proton 612

• C. Liu, R.L. Hulsart, K. Mernick, R.J. Michnoff, M.G. Minty
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
To combat triplets vibration, the global orbit feedback system with frequency about 10 Hz was developed and en- gaged in operation at injection and top energy in 2010, dur- ing beam acceleration in 2012 at RHIC. The system has performed well with keeping 6 out of 12 eigenvalues for the orbit response matrix. However, we observed correc- tor current transients with the lattice for polarized proton program in 2015 which resulted in corrector power supply trips. In this report, we will present the observation, an- alyze the cause and also optimize the feedback algorithm to overcome the newly emerged problem with the feedback system.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB55
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TUPOB61 Recent Improvements to TAPAs, the Android Application for Accelerator Physics and Engineering Calculations ion, cavity, emittance, storage-ring 625

• M. Borland

The Android application TAPAs, the Toolkit for Accelerator Physics on Androids, was released in 2012 and at present has over 300 users. TAPAs provides over 50 calculations, many of which are coupled together. Updates are released about once a month and have provided many new capabilities. Calculations for electron storage rings are a particular emphasis, and have expanded to include CSR threshold, ion trapping, Laslett tune shift, and emittance dilution. Other additions include helical superconducting undulators, rf cavity properties, Compton backscattering, and temperature calculations for mixing water.
Poster TUPOB61 [2.925 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB61
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WEA1CO03 Simulations of Booster Injection Efficiency for the APS-Upgrade ion, booster, injection, simulation 647

• J.R. Calvey, M. Borland, K.C. Harkay, R.R. Lindberg, C. Yao
ANL, Argonne, Illinois, USA

The APS-Upgrade will require the injector chain to provide high single bunch charge for swap-out injection. One possible limiting factor to achieving this is an observed reduction of injection efficiency into the booster synchrotron at high charge. We have simulated booster injection using the particle tracking code elegant, including a model for the booster impedance and beam loading in the RF cavities. The simulations point to two possible causes for reduced efficiency: energy oscillations leading to losses at high dispersion locations, and a vertical beam size blowup caused by ions in the particle accumulator ring. We also show that the efficiency is much higher in an alternate booster lattice with smaller vertical beta function and zero dispersion in the straight sections.
Slides WEA1CO03 [0.682 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEA1CO03
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WEA1CO05 Microwave Instability Studies in NSLS-II ion, simulation, wiggler, electron 655

• A. Blednykh, B. Bacha, G. Bassi, Y. Chen-Wiegart, W.X. Cheng, O.V. Chubar, V.V. Smaluk
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by Department of Energy contract DE-AC02-98CH10886.
The microwave instability in the NSLS-II has been studied for the current configuration of insertion devices, 9 In-Vacuum Undulators (IVU's), 3EPU's, 3 Damping Wigglers. The energy spread as a function of single bunch current has been measured based on the frequency spectrum of IVU for X-Ray Spectroscopy (SRX) beam line. The results for two lattices, bare lattice with nominal energy spread 0.0005 and a lattice with one DW magnet gap closed (nominal energy spread 0.0007) are compared. In addition we used a Spectrum Analyzer to measure the beam spectrum. The instability thresholds for two different lattices cross-checked numerically using the particle tracking code SPACE and longitudinal impedance.

Slides WEA1CO05 [2.380 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEA1CO05
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WEA2IO01 Calculating Spin Lifetime ion, resonance, polarization, synchrotron 667

• V.H. Ranjbar
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US Department of Energy under contract number DE-SC0012704.
We have extended a lattice independent code to integrate the Thomas-BMT equation over 2 hours of beam time in the presence of two orthogonal Siberian snakes. In tandem to this we have recast the Thomas-BMT equation in the presences of longitudinal dynamics, into the parametric resonance formalism recently developed to understand overlapping spin resonances *
* V. H. Ranjbar, "Approximations for crossing two nearby spin
resonances," Phys. Rev. ST Accel. Beams 18, no. 1, 014001
(2015). doi:10.1103/PhysRevSTAB.18.014001

Slides WEA2IO01 [2.252 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEA2IO01
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WEPOA12 Interleaving Lattice Design for APS Linac ion, linac, electron, gun 713

• S. Shin, Y. Sun, A. Zholents
ANL, Argonne, Illinois, USA

In order to realize and test advanced accelerator concepts and hardware, the existing beamline with both old and new components are being reconfigured in Linac Extension Area (LEA) of APS linac. Photo injector, which had been installed in the beginning of APS linac, will provide low emittance electron beam into the LEA. The thermionic RF gun beam for storage ring and photo-cathode RF gun beam for LEA will be operated though the LINAC in an interleaved fashion. In this presentation, technical issues as well as beam dynamics on the design for interleaving operation will be described.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA12
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WEPOA13 RF Design and Simulation of a Non-Periodic Lattice Photonic Band Gap (PBG) Accelerating Structure ion, cavity, photon, wakefield 716

• N. Zhou, A. Nassiri
ANL, Argonne, Illinois, USA

Photonic Band Gap (PBG) structures (metallic and or dielectric) have been proposed for accelerators. These structures act like a filter, allowing RF field at some frequencies to be transmitted through, while rejecting RF fields in some (unwanted) frequency range. Additionally PBG structures are used to support selective field patterns (modes) in a resonator or waveguide. In this paper, we will report on the RF design and simulation results of an X-band PBG structure, including lattice optimization, to improve RF performance.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA13
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WEPOA22 nuPIL - Neutrinos from a PIon Beam Line ion, optics, proton, detector 739

• A. Liu, A.D. Bross
Fermilab, Batavia, Illinois, USA
• J.-B. Lagrange
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

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, an FFAG 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 either a LBNF-like decay pipe, or a straight FODO beam line where they decay to produce neutrinos. Using neutrinos from this 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 current version of nuPIL design are also presented in the paper.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA22
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WEPOA36 Simulated Measurements of Beam Cooling in Muon Ionization Cooling Experiment ion, emittance, solenoid, experiment 771

• T.A. Mohayai
IIT, Chicago, Illinois, USA
• D.V. Neuffer, D.V. Neuffer, P. Snopok
Fermilab, Batavia, Illinois, USA
• C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
• P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Science Graduate Student Research (SCGSR) under contract No. DE-AC05-06OR23100.
Cooled muon beams are essential to enable future Neutrino Factory and Muon Collider facilities. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate muon beam cooling through ionization energy loss in material. A figure of merit for muon beam cooling in MICE is the transverse root-mean-square (RMS) emittance reduction and to measure this, the individual muon positions and momenta are reconstructed using two scintillating-fiber tracking detectors housed in spectrometer solenoid modules. The reconstructed positions and momenta before and after a low-Z absorbing material are then used for constructing the covariance matrix and measuring normalized transverse RMS emittance of MICE muon beam. However, RMS emittance is sensitive to nonlinear effects in beam optics. In this study, the direct measurement of phase-space density as an alternative approach to measuring the muon beam cooling using the novel Kernel Density Estimation (KDE) method, is described.

Poster WEPOA36 [1.855 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA36
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WEPOB01 Lower Emittance Lattice for the Advanced Photon Source Upgrade Using Reverse Bending Magnets ion, emittance, quadrupole, damping 877

• M. Borland, T.G. Berenc, R.R. Lindberg, V. Sajaev, Y.P. Sun
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
he Advanced Photon Source (APS) is pursuing an upgrade to the storage ring to a hybrid seven-bend-achromat design*. The nominal design provides a natural emittance of 67 pm. By adding reverse dipole fields to several quadrupoles**, we can reduce the natural emittance to 41 pm while simultaneously providing more optimal beta functions in the insertion devices. The improved emittance results from a combination of increased energy loss per turn and a change in the damping partition. At the same time, the nonlinear dynamics performance is very similar, thanks in part to increased dispersion in the sextupoles. This paper describes the properties, optimization, and performance of the new lattice.
* L. Farvacque et al., IPAC13, 79 (2013).
** J.P. Delahaye \em et al., PAC89, 1611 (1990); A. Streun, NIM A 737, 148 (2014).

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB01
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WEPOB02 Simulation of Swap-Out Reliability for the Advance Photon Source Upgrade ion, operation, injection, simulation 881

• M. Borland
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The proposed upgrade of the Advanced Photon Source (APS) to a multibend achromat lattice relies on the use of swap-out injection to accommodate the small dynamic acceptance, allow use of unusual insertion devices, and minimize collective effects at high single-bunch charge. This, combined with the short beam lifetime, will make injector reliability even more important than it is for top-up operation. We used historical data for the APS injector complex to obtain probability distributions for injector up-time and down-time durations. Using these distributions, we simulated several years of swap-out operation for the upgraded lattice for several operating modes. The results indicate that obtaining very high availability of beam in the storage ring will require improvements to injector reliability.

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WEPOB08 Collective Effects at Injection for the APS-U MBA Lattice ion, feedback, injection, collective-effects 901

• R.R. Lindberg, M. Borland
ANL, Argonne, Illinois, USA
• A. Blednykh
BNL, Upton, Long Island, New York, USA

Funding: U.S. Dept. of Energy Office of Sciences under Contract No. DE-AC02-06CH11357
The Advanced Photon Source has proposed an upgrade to a multi-bend achromat (MBA) with a proposed timing mode calls for 48 bunches of 15 nC each. In this mode of operation we find that phase space mismatch from the booster can drive large wakefields that in turn may limit the current below that of the nominal collective instability threshold. We show that collective effects at injection lead to emittance growth that makes usual off-axis accumulation very challenging. On-axis injection ameliorates many of these issues, but we find that transverse feedback is still required. We explore the role of impedance, feedback, and phase-space mismatch on transverse instabilities at injection.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB08
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• J. Liu, M. Borland, R.J. Dejus, A.T. Donnelly, C.L. Doose, J.S. Downey, M.S. Jaski
ANL, Argonne, Illinois, USA
• A.K. Jain
BNL, Upton, Long Island, New York, USA

Funding: *Work supported by U.S. Department of Energy, Office of Science, under contract No. DE-AC02-06CH11357 and contract number DE-SC0012704 for work associated with Brookhaven National Laboratory.
The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is considering upgrading the current double-bend, 7-GeV, 3rd generation storage ring to a 6-GeV, 4th generation storage ring with a Multibend Achromat (MBA) lattice. In this study, a novel method is proposed to determine fabrication and assembly tolerances through a combination of magnetic and mechanical tolerance analyses. Mechanical tolerance stackup analyses using Teamcenter Variation Analysis are carried out to determine the part and assembly level fabrication tolerances. Finite element analyses using OPERA are conducted to estimate the effect of fabrication and assembly errors on the magnetic field of a quadrupole magnet and to determine the allowable tolerances to achieve the desired magnetic performance. Finally, results of measurements in R&D quadrupole prototypes are compared with the analysis results.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB09
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WEPOB10 Simulation Study of the Helical Superconducting Undulator Installation at the Advanced Photon Source ion, undulator, sextupole, injection 907

• V. Sajaev, M. Borland, Y.P. Sun, A. Xiao
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
A helical superconducting undulator is planned for installation at the APS. Such an installation would be first of its kind – helical devices were never installed in synchrotron light sources before. Due to its reduced horizontal aperture, a lattice modification is required to accommodate for large horizontal oscillations during injection. We describe the lattice change details and show the new lattice experimental test results. To understand the effect of the undulator on single-particle dynamics, first, its kick maps were computed using different methods. We have found that often-used Elleaume formula* for kick maps gives wrong results for this undulator. We then used the kick maps obtained by other methods to simulate the effect of the undulator on injection and lifetime.
*P. Elleaume, EPAC 1992

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB10
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WEPOB12 Multi-Objective Online Optimization of Beam Lifetime at APS ion, sextupole, simulation, storage-ring 913

• Y.P. Sun
ANL, Argonne, Illinois, USA

In this paper, online optimization of beam lifetime at the APS (Advanced Photon Source) storage ring is presented. A general genetic algorithm (GA) is developed and employed for some online optimizations in the APS storage ring. Sextupole magnets in 40 sectors of the APS storage ring are employed as variables for the online nonlinear beam dynamics optimization. The algorithm employs several optimization objectives and is designed to run with topup mode or beam current decay mode. Up to 50\% improvement of beam lifetime is demonstrated, without affecting the transverse beam sizes and other relevant parameters. In some cases, the top-up injection efficiency is also improved.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB12
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WEPOB13 Online Minimization of Vertical Beam Sizes at APS ion, storage-ring, operation, photon 916

• Y.P. Sun
ANL, Argonne, Illinois, USA

In this paper, online minimization of vertical beam sizes along the APS (Advanced Photon Source) storage ring is presented. A genetic algorithm (GA) was developed and employed for the online optimization in the APS storage ring. A total of 59 families of skew quadrupole magnets were employed as knobs to adjust the coupling and the vertical dispersion in the APS storage ring. Starting from initially zero current skew quadrupoles, small vertical beam sizes along the APS storage ring were achieved in a short optimization time of one hour. The optimization results from this method are briefly compared with the one from LOCO (Linear Optics from Closed Orbits) response matrix correction.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB13
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WEPOB14 APS-U Lattice Design for Off-Axis Accumulation ion, emittance, injection, quadrupole 920

• Y.P. Sun, M. Borland, R.R. Lindberg, V. Sajaev
ANL, Argonne, Illinois, USA

A 67-pm hybrid-seven-bend achromat (H7BA) lattice is being proposed for a future Advanced Photon Source (APS) multi-bend-achromat (MBA) upgrade project. This lattice design pushes for smaller emittance and requires use of a swap-out (on-axis) injection scheme due to limited dynamic acceptance. Alternate lattice design work has also been performed for the APS upgrade to achieve better beam dynamics performance than the nominal APS MBA lattice, in order to allow off-axis accumulation. Two such alternate H7BA lattice designs, which target a still-low emittance of 90 pm, are discussed in detail in this paper. Although the single-particle-dynamics performance is good, simulations of collective effects indicate that surprising difficulty would be expected accumulating high single-bunch charge in this lattice. The brightness of the 90-pm lattice is also a factor of two lower than the 67-pm H7BA lattice.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB14
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WEPOB15 Comparison of Nonlinear Dynamics Optimization Methods for APS-U ion, sextupole, octupole, optics 924

• Y.P. Sun, M. Borland
ANL, Argonne, Illinois, USA

Many different objectives and genetic algorithms have been proposed for storage ring nonlinear dynamics performance optimization. These optimization objectives include nonlinear chromaticities and driving/detuning terms, on-momentum and off-momentum dynamic acceptance, chromatic detuning, local momentum acceptance, variation of transverse invariant, Touschek lifetime, etc. In this paper, the effectiveness of several different optimization methods and objectives are compared for the nonlinear beam dynamics optimization of the Advanced Photon Source upgrade (APS-U) lattice. The optimized solutions from these different methods are preliminarily compared in terms of the dynamic acceptance, local momentum acceptance, chromatic detuning, and other performance measures.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB15
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WEPOB18 Bend Magnet Head Loads and Out of Orbit Scenarios ion, photon, software, electron 931

• T.T. Valicenti, J.A. Carter, P.K. Den Hartog, K.J. Suthar
ANL, Argonne, Illinois, USA

This paper presents an analytical calculation of the spatial power spectrum emitted from relativistic electrons passing through a series of bend magnets. Using lattice files from the software Elegant, both the ideal and missteered trajectories taken by the beam are considered in determination of the power profile. Calculations were performed for the Advanced Photon Source Upgrade multi-bend-achromat storage-ring. Results were validated with Synrad, a monte-carlo based program designed at CERN. The power distribution and integrated total power values are in agreement with Synrad's results within one percent error. The analytic solution used in this software gives a both quick and accurate tool for calculating the heat load on a photon absorber. The location and orientation can be optimized in order to reduce the peak intensity and thus the maximum thermal stress. This can be used with any optimization or FEA software and gives rise to a versatile set of uses for the developed program.
Poster WEPOB18 [2.491 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB18
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WEPOB36 Upgrade of the Cornell Electron Storage Ring as a Synchrotron Light Source ion, undulator, injection, emittance 980

• D. L. Rubin, J.A. Crittenden, J.P. Shanks, S. Wang
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: NSF-DMR 13-32208
The planned upgrade of the Cornell Electron Storage Ring as an X-ray source for CHESS will include an increase in beam energy and decrease in emittance from 100 nm-rad at 5.3 GeV to 30 nm-rad at 6 GeV, increase in beam current from 120 to 200 mA, continuous top-off injection of the single circulating beam, and four new zero dispersion inser- tion straights that can each accommodate a pair of canted undulators. The existing sextant of the storage ring arc that serves as the source for all of the CHESS X-ray beam lines will be reconfigured with 6 double-bend achromats, each consisting of two pairs of horizontally focusing quadrupoles, and a single pair of combined-function gradient bend magnets. The chromaticity will be compensated by the existing sextupoles in the legacy FODO arcs. We describe details of the linear optics, sextupole distributions to maximize dynamic aperture and injection efficiency, and characterization of magnetic field and alignment error tolerance.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB36
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WEPOB65 Experiments of Lossless Crossing - Resonance With Tune Modulation by Synchrotron Oscillations ion, resonance, experiment, quadrupole 1036

• G.M. Wang, B. Holub, Y. Li, J. Rose, T.V. Shaftan, V.V. Smaluk
BNL, Upton, Long Island, New York, USA

It had become a standard practice to constrain particle's tune footprint while designing the storage ring lattice so that the tunes fit between harmful resonances that limit ring dynamic aperture (DA). However, in recent ultra-bright light source design, the nonlinearities of storage ring lattices are much enhanced as compared with the 3rd generation light source one. It is becoming more and more difficult to keep the off-momentum tune footprint confined and even more, the solution cannot be found to confine off-energy tune footprint in certain cases. The questions have been asked whether crossing of a resonance stopband from off-momentum particle will necessarily lead to particle loss. In NSLS-II, we modified the lattice working point to mimic machine tune footprint crossing half integer with beam synchrotron oscillation excitation and demonstrated that beam can cross a resonance without loss with control of stopband width and high order chromaticity.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOB65
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THA1CO03 MAX IV and Solaris 1.5 GeV Storage Rings Magnet Block Production Series Measurement Results ion, storage-ring, synchrotron, magnet-design 1058

• M.A.G. Johansson
MAX IV Laboratory, Lund University, Lund, Sweden
• K. Karaś
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
• R. Nietubyć
NCBJ, Świerk/Otwock, Poland

The magnet design of the MAX IV and Solaris 1.5 GeV storage rings replaces the conventional support girder + discrete magnets scheme of previous third-generation synchrotron radiation light sources with an integrated design having several consecutive magnet elements precision-machined out of a common solid iron block, with mechanical tolerances of ±0.02 mm over the 4.5 m block length. The production series of 12+12 integrated magnet block units, which was totally outsourced to industry, was completed in the spring of 2015, with mechanical and magnetic QA conforming to specifications. This article presents mechanical and magnetic field measurement results of the full production series.
Slides THA1CO03 [7.517 MB]
Poster THA1CO03 [1.117 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THA1CO03
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• M. Borland, R.R. Lindberg
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice requires shorter and much stronger quadrupole magnets than are present in the existing ring. This results in longitudinal gradient profiles that differ significantly from a hard-edge model. Additionally, the lattice assumes the use of five-segment longitudinal gradient dipoles. Under these circumstances, the effects of fringe fields and detailed field distributions are of interest. We evaluated the effect of soft-edge fringe fields on the linear optics and chromaticity, finding that compensation for these effects is readily accomplished. In addition, we evaluated the reliability of standard methods of simulating hard-edge nonlinear fringe effects in quadrupoles.

DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA13
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THPOA19 Design Considerations for Proposed Fermilab Integrable RCS ion, booster, optics, proton 1138

• J.S. Eldred, A. Valishev
Fermilab, Batavia, Illinois, USA

Integrable optics is an innovation in particle accelerator design that provides strong nonlinear focusing while avoiding parametric resonances. One promising application of integrable optics is to overcome the traditional limits on accelerator intensity imposed by betatron tune-spread and collective instabilities. The efficacy of high-intensity integrable accelerators will be undergo comprehensive testing over the next several years at the Fermilab Integrable Optics Test Accelerator (IOTA) and the University of Maryland Electron Ring (UMER). We propose an integrable RCS (iRCS) as a replacement for the Fermilab Booster to achieve multi-MW beam power for the Fermilab high-energy neutrino program. We provide a overview of the machine parameters and discuss an approach to lattice optimization. Integrable optics requires arcs with integer-pi phase advance followed by drifts with matched beta functions. We provide an example integrable lattice with features of a modern RCS - long dispersion-free drifts, low momentum compaction, superperiodicity, chromaticity correction, separate-function magnets, and bounded beta functions.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA19
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THPOA22 Linear Lattice and Trajectory Reconstruction and Correction at FAST Linear Accelerator ion, experiment, cavity, solenoid 1149

• A.L. Romanov, D.R. Edstrom
Fermilab, Batavia, Illinois, USA
• A. Halavanau
Northern Illinois University, DeKalb, Illinois, USA

Low energy part of FAST linear accelerator based on 1.3 GHz superconducting RF cavities was successfully commissioned. During commissioning, beam based model dependent methods were used to correct linear lattice and trajectory. Lattice correction algorithm is based on analysis of beam shape from profile monitors and trajectory responses to dipole correctors. Trajectory responses to field gradient variations in quadrupoles and phase variations in superconducting RF cavities were used to correct bunch offsets in quadrupoles and accelerating cavities relative to its magnetic axes. Details of used methods and experimental results are presented.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA22
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THPOA23 Adaptive Matching of the IOTA Ring Linear Optics for Space Charge Compensation ion, space-charge, insertion, experiment 1152

• A.L. Romanov, A. Valishev
Fermilab, Batavia, Illinois, USA
• D.L. Bruhwiler, N.M. Cook, C.C. Hall

Many present and future accelerators must operate with high intensity beams when distortions induced by space charge forces are among major limiting factors. Betatron tune depression of above approximately 0.1 per cell leads to significant distortions of linear optics. Many aspects of machine operation depend on proper relations between lattice functions and phase advances, and can be improved with proper treatment of space charge effects. We implement an adaptive algorithm for linear lattice re-matching with full account of space charge in the linear approximation for the case of Fermilab's IOTA ring. The method is based on a search for initial second moments that give closed solution and, at the same time, satisfy predefined set of goals for emittances, beta functions, dispersions and phase advances at and between points of interest. Iterative singular value decomposition based technique is used to search for optimum by varying wide array of model parameters.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA23
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THPOA24 Testing of Advanced Technique for Linear Lattice and Closed Orbit Correction by Modeling Its Application for IOTA Ring at Fermilab ion, experiment, closed-orbit, insertion 1155

• A.L. Romanov
Fermilab, Batavia, Illinois, USA

Many modern and most future accelerators rely on precise configuration of lattice and trajectory. Integrable Optics Test Accelerator (IOTA) at Fermilab that is coming to final stages of construction will be used to test advanced approaches of control over particles dynamics. Various experiments planned at IOTA require high flexibility of lattice configuration as well as high precision of lattice and closed orbit control. Dense element placement does not allow to have ideal configuration of diagnostics and correctors for all planned experiments. To overcome this limitations advanced method of lattice analysis is proposed that can also be beneficial for other machines. Developed algorithm is based on LOCO approach, extended with various sets of other experimental data, such as dispersion, BPM-to-BPM phase advances, beam shape information from synchrotron light monitors, responses of closed orbit bumps to variations of focusing elements and other. Extensive modeling of corrections for a big number of random seed errors is used to illustrate benefits from developed approach.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA24
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THPOA35 Analysis of Microbunching Structures in Transverse and Longitudinal Phase Spaces ion, bunching, simulation, electron 1177

• C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
• R. Li
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Microbunching instability (MBI) has been a challenging issue in high-brightness electron beam transport for modern accelerators. The existing Vlasov analysis of MBI is based on single-pass configuration*. For multi-pass recirculation or a long beamline, the intuitive argument of quantifying MBI, by successive multiplication of MBI gains, was found to underestimate the effect**. More thorough analyses based on concatenation of gain matrices aimed to combine both density and energy modulations for a general beamline**. Yet, quantification still focuses on characterizing longitudinal phase space; microbunching residing in (x,z) or (x',z) was observed in particle tracking simulation. Inclusion of such cross-plane microbunching structures in Vlasov analysis shall be a crucial step to systematically characterize MBI for a beamline complex in terms of concatenating individual beamline segments. We derived a semi-analytical formulation to include the microbunching structures in longitudinal and transverse phase spaces. Having numerically implemented the generalized formulae, an example lattice*** is studied and reasonable agreement achieved when compared with particle tracking simulation.
* Heifets et al., PRSTAB 5, 064401 (2002), Huang and Kim, PRSTAB 5, 074401 (2002), and Vneturini, PRSTAB 10, 104401 (2007)
** Tsai et al., IPAC'16 (TUPOR020)
*** Di Mitri, PRSTAB 17, 074401 (2014)

Poster THPOA35 [4.710 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA35
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THPOA58 Multiple Bunch Length Operation Mode Design at HLS-II Storage Ring ion, cavity, radiation, storage-ring 1220

• W.W. Gao
Fujian University of Technology, Fuzhou, People's Republic of China
• W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: * Project supported by the National Natural Science Foundation of China (Grant No.11305170)
In this paper we design a simultaneous three bunch length operating mode at the HLS-II (Hefei Light Source II) storage ring by installing two harmonic cavities and minimizing the momentum compaction factor. The short bunches (2.6 mm) presented in this work will meet the requirement of coherent THz radiation experiments, and the long bunches (20 mm) will efficiently increase the total beam current. Therefore, this multiple-bunch-length operating mode allows present synchrotron users and THz users to carry out their experiments simultaneously. Also we analyzed the physical properties such as the CSR effect, RF jitter and Touschek lifetime of this operating mode.

Poster THPOA58 [0.611 MB]
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA58
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THPOA61 A Possible Emittance Reduction Scheme for PLSII ion, emittance, quadrupole, electron 1226

• T.-Y. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

As the upgrade of PLS, PLSII is a 3 GeV light source in 12 super-periods (281.8 m circumference) with 5.8 nm design emittance and can store electron beam up to 400 mA with 3 superconducting RF cavities. PLSII lattice is a double bend achromatic (DBA) lattice with 2 straight sections for each cell (24 straight sections). After comple-tion of PLSII, multi-bend achromatic lattice has widely been adopted to accomplish low emittance. This paper discusses how a minimal change can modify the PLSII's DBA to a quadruple bend achromatic (QBA) lattice and reduce the emittance to about a half value.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA61
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THPOA65 Double Triple Bend Achromat for Next Generation 3 GeV Light Sources ion, injection, optics, SRF 1237

• A. Alekou, R. Bartolini
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
• A. Alekou, R. Bartolini
JAI, Oxford, United Kingdom
• A. Alekou, R. Bartolini, T. Pulampong, R.P. Walker
DLS, Oxfordshire, United Kingdom
• N. Carmignani, S.M. Liuzzo, P. Raimondi
ESRF, Grenoble, France

The Double Triple Bend Achromat (DTBA) is a newly designed cell for a next generation 3 GeV synchrotron light source. DTBA is inspired by the Double-Double Bend Achromat (DDBA) cell designed for Diamond and originates from a modification of the ESRF HMBA 6 GeV cell, combining in this way the best characteristics of each lattice. The lattice achieves a natural emittance as low as 131 pm, together with a sufficient Dynamic Aperture (DA) for injection and lifetime. Two cells are designed with different end-drift lengths providing two different Long Straight Sections (LSS) for insertion devices, 5 and 7.5 m long, in addition to a new middle-straight section of 3 m. The characteristics of the lattice together with the results on emittance, DA and Touschek lifetime are presented after extensive linear and non-linear optimisations, with and without the presence of errors and corrections.
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA65
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