IPAC2016 - List of Keywords (insertion)

Paper	Title	Other Keywords	Page
MOPMR057	Measurements using Button BPM SUM Signal	electronics, storage-ring, operation, beam-losses	377
	W.X. Cheng, K. Ha, J. Mead, O. Singh, G.M. Wang BNL, Upton, Long Island, New York, USA
	Modern digital BPM detectors measure not only the beam positions, four buttons SUM signal can be very helpful for machine developments and operations. At NSLS-II, BPM SUM signal has been used from commissioning stage, to investigate localized beam losses. During top-off operation, precise beam lifetime measurement within relative short period of time becomes important. With many BPMs along the ring, BPM SUM can be a much more accurate tool to measure the beam current and lifetime. BPM SUM signal shall be proportional to beam current, and it may depends on button sizes and BPM chamber geometry, cable attenuations, electronics attenuations, beam position, bunch lengths, fill pattern etc. Experience of BPM SUM signals measurements will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR057
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MOPOR007	Local Impedance Measurements at ALBA from Turn-by-Turn Acquisition	impedance, lattice, vacuum, optics	598
	M. Carlà, G. Benedetti, T.F.G. Günzel, U. Iriso, Z. Martí ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	A transverse impedance source manifests itself, among other ways, by producing a small defocusing kick which depends on the beam bunch charge. By repeating optics measurements for different bunch charges, it is possible to disentangle the contribution produced by each impedance source from the dominating focusing effects given by the machine optics. But hunting for such faint defocusing effects poses strong requirements on the precision and sensibility of the measurements, and slow machine drifts or different thermal conditions shall be avoided. In this report, we present a novel method to assess in a fast and precise manner machine optics for different bunch charges using BPM turn-by-turn data and hybrid filling patterns. Finally, measurements for different ALBA machine components like scrapers and In-vacuum undulators are compared with simulation results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR007
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MOPOY028	Low Power RF Tuning of the CSNS DTL	DTL, cavity, linac, neutron	913
	H.C. Liu, Q. Chen, M.X. Fan, S. Fu, K.Y. Gong, A.H. Li, J. Peng, S. Wang, X. Wu, F.X. Zhao IHEP, Beijing, People's Republic of China B. Li, P.H. Qu, Y. Wang CSNS, Guangdong Province, People's Republic of China
	The China Spallation Neutron Source (CSNS) is an accelerator-based neutron source being built at dongguan, Guangdong province in China. A conventional 324MHz Alvarez-type Drift tube linac (DTL) is utilized to accelerate an H⁻ ion beam from 3MeV to 80MeV. The RF field tuning of DTL is necessary for compensating the unexpected error caused by manufacturing and assembling. For reasons of RF power saving it is convenient to build a long DTL tank, but this choice involves risks of accelerating field instability. This problem can be fixed by using the resonant coupling stabilization method and equipping DTL cavities with a series of post-couplers. A practical tuning method was proposed, an acceptable field distribution with a good stability was achieved for CSNS DTL-1.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY028
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TUPMR054	Simulation of the FCC-hh Collimation System	collimation, betatron, proton, simulation	1381
	J. Molson, P. Bambade, S. Chancé, A. Faus-Golfe LAL, Orsay, France
	Funding: Funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305. Funding also from ANR-11-IDEX-0003-02. The proposed CERN FCC-hh proton-proton collider will operate at unprecedented per-particle (50 TeV) and total stored beam energies (8.4 GJ). These high energies create the requirement for an efficient collimation system in order to protect the accelerator components and experiments. In order to verify the performance of proposed collimation system designs, loss map simulations have been performed using the code Merlin. Results for the current baseline layout are presented for both betatron and off-momentum loss maps.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR054
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TUPMW014	Improved Aperture Measurements at the LHC and Results from their Application in 2015	alignment, injection, operation, beam-losses	1446
	P.D. Hermes, R. Bruce, M. Fiascaris, H. Garcia, M. Giovannozzi, A. Mereghetti, D. Mirarchi, E. Quaranta, S. Redaelli, B. Salvachua, G. Valentino CERN, Geneva, Switzerland R. Kwee-Hinzmann Royal Holloway, University of London, Surrey, United Kingdom E. Quaranta Politecnico/Milano, Milano, Italy
	A good knowledge of the available aperture in the LHC is essential for a safe operation due to the risk of magnet quenches or even damage in case of uncontrolled beam losses. Experimental validations of the available aperture are therefore crucial and were in the past carried out by either a collimator scan combined with beam excitations or through the use of local orbit bumps. In this paper, we show a first comparison of these methods in the same machine configuration, as well as a new very fast method based on a beam-based collimator alignment and a new faster variant of the collimator scan method. The methods are applied to the LHC operational configuration for 2015 at injection and with squeezed beams and the measured apertures are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW014
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TUPMW021	Roman Pot Insertions in High-Intensity Beams for the CT-PPS Project at LHC	impedance, proton, luminosity, vacuum	1473
	M. Deile, R. Bruce, A. Mereghetti, D. Mirarchi, S. Redaelli, B. Salvachua, B. Salvant, G. Valentino CERN, Geneva, Switzerland
	The CMS-TOTEM Precision Proton Spectrometer (CT-PPS) at the LHC IP5 aims at exploring diffractive physics at high luminosity in standard LHC fills. It is based on 14 Roman Pots (RPs), designed to host tracking and time-of-flight detectors for measuring the kinematics of leading protons. To reach the physics goals, the RPs will finally have to approach the beams to distances of 15 beam σs (i.e. ~1.5 mm) or closer. After problems with showers and impedance heating in first high-luminosity RP insertions in 2012, the LS1 of LHC was used for upgrades in view of impedance minimisation and for adding new collimators to intercept RP-induced showers. In 2015 the effectiveness of these improvements was shown by successfully inserting the RPs in all LHC beam intensity steps to a first-phase distance of ~25 σs. This contribution reviews the measurements of debris showers and impedance effects, i.e. the data from Beam Loss Monitors, beam vacuum gauges and temperature sensors. The dependences of the observables on the luminosity are shown. Extrapolations to L=10³⁴ cm^-2 s^-1 and smaller distances to the beam do not indicate any fundamental problems. The plans for 2016 are outlined.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW021
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WEPMR038	Frequency Tuning for a DQW Crab Cavity	cavity, operation, simulation, SRF	2357
	S. Verdú-Andrés, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA K. Artoos, R. Calaga, O. Capatina, R. Leuxe, C. Zanoni CERN, Geneva, Switzerland I. Ben-Zvi Stony Brook University, Stony Brook, USA
	Funding: Work supported by US DOE via BSA LLC contract No.DE-AC02-98CH10886, the US LARP program, US DOE contract No. DE-AC02-05CH1123 (NERSC resources) and by HiLumi project. The nominal operating frequency for the HL-LHC crab cavities is 400.79 MHz within a bandwidth of ±60kHz. Attaining the required cavity tune implies a good understanding of all the processes that influence the cavity frequency from the moment when the cavity parts are being fabricated until the cavity is installed and under operation. Different tuning options will be available for the DQW crab cavity of LHC. This paper details the different steps in the cavity fabrication and preparation that may introduce a shift in the cavity frequency and introduces the different tuning methods foreseen to bring the cavity frequency to meet the specifications.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR038
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WEPMR058	Survey and Alignment for Taiwan Photon Source Storage Ring	survey, storage-ring, network, alignment	2405
	W.Y. Lai, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, C.J. Lin, S.Y. Perng, C.W. Tsai, T.C. Tseng, H.S. Wang NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a 3 Gev synchrotron light source located in Hsinchu, Taiwan. The commissioning of the beam began on December 2014, and the phase 1 stored current of 100mA was achieved on March 2015. Then the installation and alignment of insertion device were complete during the shutdown from April to July, and also the scheduled maintenance of survey control points was complete in the meantime. This report presents survey alignment results and experience of the TPS .
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR058
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WEPMW006	First Design of a Proton Collimation System for 50 TeV FCC-hh	collimation, betatron, collider, proton	2423
	M. Fiascaris, R. Bruce, D. Mirarchi, S. Redaelli CERN, Geneva, Switzerland
	We present studies aimed at defining a first conceptual solution for a collimation system for the hadron-hadron option for the Future Circular Collider (FCC-hh). The baseline collimation layout is based on the scaling of the present LHC collimation system to the FCC-hh energy. It currently includes a dedicated betatron cleaning insertion as well as collimators in the experimental insertions to protect the inner triplets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at top energy taking into account mechanical and optics imperfections. Based on these studies the collimator settings needed to protect the machine are defined. The performance of the collimation system is then assessed with particle tracking simulation tools assuming a perfect machine.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW006
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WEPMW030	Cleaning Performance of the Collimation System of the High Luminosity Large Hadron Collider	collimation, ion, luminosity, simulation	2494
	D. Mirarchi, A. Bertarelli, R. Bruce, F. Cerutti, P.D. Hermes, A. Lechner, A. Mereghetti, E. Quaranta, S. Redaelli CERN, Geneva, Switzerland R.B. Appleby UMAN, Manchester, United Kingdom H. Garcia Morales, R. Kwee-Hinzmann Royal Holloway, University of London, Surrey, United Kingdom
	Different upgrades of the LHC will be carried out in the framework of the High Luminosity project (HL-LHC), where the total stored energy in the machine will increase up to about 700 MJ. This unprecedented stored energy poses serious challenges for the collimation system, which was designed to handle safely up to about 360 MJ. In this paper the baseline collimation layout for HL-LHC is described, with main focus on upgrades related to the cleaning of halo and physics debris, and its expected performance is discussed. The main upgrade items include the presence of new collimators in the dispersion suppressor of the betatron cleaning insertion installed between two 11 T dipoles, and two additional collimators for an improved local protection of triplet magnets. Thus, optimized settings for the entire and upgraded collimation chain were conceived and are shown here together with the resulting cleaning performance. Moreover, the cleaning performance taking into account crab cavities it is also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW030
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WEPMY038	Optimization of C-band RF Input Coupler as a Mode Converter for 20-K Cryocooled Photocathode RF Gun	cavity, gun, coupling, simulation	2638
	T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka LEBRA, Funabashi, Japan M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT). Development of a cryocooled 2.6-cell C-band photocathode RF gun has been conducted at Nihon University in collaboration with KEK. An RF mode converter from square TE10 to circular TM01 mode has been employed as an RF input coupler that has a coupling coefficient of approximately 20 at 20 K to the 2.6-cell accelerating structure. In the previous design, the circular waveguide in the mode converter formed part of the accelerating cavity. After the cold test of the cavity completed in 2014, the coupler design was modified to work as a pure mode converter with a VSWR of 1 at 5712 MHz. From the design simulation using CST-STUDIO, the insertion loss in the converter is 0.2 %. The TM010 and TM011 modes excited in the circular waveguide were separated by several ten MHz from the accelerating frequency. The simulation has suggested that the amplitude of the transverse electric filed on the axis in the circular waveguide is reduced to approximately 2 % of that in the longitudinal direction.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY038
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WEPOW018	Elettra Status and Upgrades	emittance, operation, insertion-device, wiggler	2864
	E. Karantzoulis, A. Carniel, S. Krecic, C. P. Pasotti Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the possible future upgrades especially concerning the next ultra low emittance light source Elettra2.0.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW018
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WEPOW046	Status of the Front Ends Project at MAXIV	storage-ring, radiation, vacuum, insertion-device	2947
	A. Bartalesi, Y. Cerenius MAX IV Laboratory, Lund University, Lund, Sweden S. Forcat Oller SLAC, Menlo Park, California, USA
	The MAX IV laboratory is a Swedish national laboratory for synchrotron radiation hosted by the Lund University. It will operate two storage rings to produce synchrotron light of very high intensity and quality over a broad wavelength range. A linear accelerator will feed these storage rings in topping up mode as well as serve as an electron source for a short pulse facility built on its extension. The storage rings have different sizes and operates at different energies: the MAX IV 1.5 GeV ring has 12 straight sections optimized for soft x-rays; while the MAX IV 3.0 GeV ring, has 20 straight sections, optimized for harder x-rays. In the initial stage of the project, five beamlines are foreseen to operate on the 3 GeV storage ring and an additional five on the 1.5 GeV ring. Each beamline requires a front end to interface the different characteristics in terms of vacuum level, heat loads, radiation safety, beam size and position, with respect to the storage ring. This paper describes the status of the different Front Ends project at MAXIV.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW046
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THEA01	Learn to Read Korean: An Introduction to the Hangul Alphabet	factory, ion, site, distributed	3207
	Z. Handel University of Washington, Seattle, Washington, USA
	In the mid 15th century the Korean scholar-king Sejong invented Hangul, the native Korean alphabet. This was the beginning of a long process by which Hangul has gradually supplanted Chinese characters as Korea's primary script, a process which is still ongoing today. This presentation will introduce the historical and cultural background behind the invention of Hangul and describe the systematic linguistic principles on which it is based. The 1446 text that introduced Hangul proclaimed that it was so simple that "a wise man can master it in a morning, and even a stupid person can learn it in ten days." We will put this claim to the test by attempting to learn to read Korean during the 30-minute presentation.
	Slides THEA01 [14.724 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THEA01
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THPMB023	Lattice Compensation of the Wiggler Effect in HLSII with Particle Swarm Optimization	wiggler, storage-ring, lattice, insertion-device	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.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB023
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THPMR038	Non-Linear Errors in the Experimental Insertions of the LHC	multipole, coupling, dipole, dynamic-aperture	3472
	E.H. Maclean, F.S. Carlier, M. Giovannozzi, A. Langner, S. Mönig, T. Persson, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland
	Correction of nonlinear magnetic errors in low-β insertions can be of critical significance for the operation of a collider. This is expected to be of particular relevance to LHC Run II and the HL-LHC upgrade, as well as to future colliders such as the FCC. Current correction strategies for these accelerators have assumed it will be possible to calculate optimized local corrections through the insertions using a magnetic model of the errors. To test this assumption the nonlinear errors in the LHC experimental insertions have been examined via feed-down and amplitude detuning. It will be shown that while in some cases the magnetic measurements provide a sufficient description of the errors, in others large discrepancies exist which will require beam-based correction techniques.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR038
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THPMR049	Minimization of Nonlinear Effects of Insertion Devices at SPS Storage Ring	electron, wiggler, multipole, storage-ring	3515
	P. Sunwong, P. Klysubun, S. Kongtawong, S. Krainara, T. Pulampong, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand T. Pulampong JAI, Oxford, United Kingdom
	Funding: Synchrotron Light Research Institute PO. Box 93 Nakhon Ratchasima 30000 Thailand Nonlinear effects of insertion devices were studied for the Siam Photon Source (SPS) storage ring. Despite the fact that shimming technique was used to minimize the nonlinear components of magnetic field integral arising from random errors, the nonlinear dynamics effects still remain. It was found that calculated dynamic field integrals are largest in the 2.2 T Hybrid Multipole Wiggler (MPW). Dynamics effects of insertion devices are attributed to the wiggling trajectory of electron in the region of magnetic field roll-off due to finite pole width. For better and more effective operation of the SPS storage ring, multipole components of the dynamic field integral in the MPW have to be further reduced.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR049
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THPOW046	Status of Insertion Device Measurement Systems at MAX IV Laboratory	insertion-device, controls, vacuum, undulator	4047
	M. Ebbeni, H. Tarawneh, A. Thiel MAX IV Laboratory, Lund University, Lund, Sweden
	An insertion device lab was setup at MAX IV Laboratory and the production of insertion devices, mainly out-of-vacuum is ongoing and aided by new magnetic measurement systems. A new 5.5 m long Hall probe bench is used for field map measurements and a new hybrid flip coil and stretch wire system will be used for field integrals of full devices as well as individual magnet blocks characterisation. This paper describes these magnetic measurement systems and their achieved and expected performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW046
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Paper

Title

Other Keywords

Page

MOPMR057

Measurements using Button BPM SUM Signal

electronics, storage-ring, operation, beam-losses

377

W.X. Cheng, K. Ha, J. Mead, O. Singh, G.M. Wang
BNL, Upton, Long Island, New York, USA

Modern digital BPM detectors measure not only the beam positions, four buttons SUM signal can be very helpful for machine developments and operations. At NSLS-II, BPM SUM signal has been used from commissioning stage, to investigate localized beam losses. During top-off operation, precise beam lifetime measurement within relative short period of time becomes important. With many BPMs along the ring, BPM SUM can be a much more accurate tool to measure the beam current and lifetime. BPM SUM signal shall be proportional to beam current, and it may depends on button sizes and BPM chamber geometry, cable attenuations, electronics attenuations, beam position, bunch lengths, fill pattern etc. Experience of BPM SUM signals measurements will be presented.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR057

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MOPOR007

Local Impedance Measurements at ALBA from Turn-by-Turn Acquisition

impedance, lattice, vacuum, optics

598

M. Carlà, G. Benedetti, T.F.G. Günzel, U. Iriso, Z. Martí
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

A transverse impedance source manifests itself, among other ways, by producing a small defocusing kick which depends on the beam bunch charge. By repeating optics measurements for different bunch charges, it is possible to disentangle the contribution produced by each impedance source from the dominating focusing effects given by the machine optics. But hunting for such faint defocusing effects poses strong requirements on the precision and sensibility of the measurements, and slow machine drifts or different thermal conditions shall be avoided. In this report, we present a novel method to assess in a fast and precise manner machine optics for different bunch charges using BPM turn-by-turn data and hybrid filling patterns. Finally, measurements for different ALBA machine components like scrapers and In-vacuum undulators are compared with simulation results.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR007

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MOPOY028

Low Power RF Tuning of the CSNS DTL

DTL, cavity, linac, neutron

913

H.C. Liu, Q. Chen, M.X. Fan, S. Fu, K.Y. Gong, A.H. Li, J. Peng, S. Wang, X. Wu, F.X. Zhao
IHEP, Beijing, People's Republic of China
B. Li, P.H. Qu, Y. Wang
CSNS, Guangdong Province, People's Republic of China

The China Spallation Neutron Source (CSNS) is an accelerator-based neutron source being built at dongguan, Guangdong province in China. A conventional 324MHz Alvarez-type Drift tube linac (DTL) is utilized to accelerate an H⁻ ion beam from 3MeV to 80MeV. The RF field tuning of DTL is necessary for compensating the unexpected error caused by manufacturing and assembling. For reasons of RF power saving it is convenient to build a long DTL tank, but this choice involves risks of accelerating field instability. This problem can be fixed by using the resonant coupling stabilization method and equipping DTL cavities with a series of post-couplers. A practical tuning method was proposed, an acceptable field distribution with a good stability was achieved for CSNS DTL-1.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY028

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TUPMR054

Simulation of the FCC-hh Collimation System

collimation, betatron, proton, simulation

1381

J. Molson, P. Bambade, S. Chancé, A. Faus-Golfe
LAL, Orsay, France

Funding: Funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305. Funding also from ANR-11-IDEX-0003-02.
The proposed CERN FCC-hh proton-proton collider will operate at unprecedented per-particle (50 TeV) and total stored beam energies (8.4 GJ). These high energies create the requirement for an efficient collimation system in order to protect the accelerator components and experiments. In order to verify the performance of proposed collimation system designs, loss map simulations have been performed using the code Merlin. Results for the current baseline layout are presented for both betatron and off-momentum loss maps.

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TUPMW014

Improved Aperture Measurements at the LHC and Results from their Application in 2015

alignment, injection, operation, beam-losses

1446

P.D. Hermes, R. Bruce, M. Fiascaris, H. Garcia, M. Giovannozzi, A. Mereghetti, D. Mirarchi, E. Quaranta, S. Redaelli, B. Salvachua, G. Valentino
CERN, Geneva, Switzerland
R. Kwee-Hinzmann
Royal Holloway, University of London, Surrey, United Kingdom
E. Quaranta
Politecnico/Milano, Milano, Italy

A good knowledge of the available aperture in the LHC is essential for a safe operation due to the risk of magnet quenches or even damage in case of uncontrolled beam losses. Experimental validations of the available aperture are therefore crucial and were in the past carried out by either a collimator scan combined with beam excitations or through the use of local orbit bumps. In this paper, we show a first comparison of these methods in the same machine configuration, as well as a new very fast method based on a beam-based collimator alignment and a new faster variant of the collimator scan method. The methods are applied to the LHC operational configuration for 2015 at injection and with squeezed beams and the measured apertures are presented.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW014

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TUPMW021

Roman Pot Insertions in High-Intensity Beams for the CT-PPS Project at LHC

impedance, proton, luminosity, vacuum

1473

M. Deile, R. Bruce, A. Mereghetti, D. Mirarchi, S. Redaelli, B. Salvachua, B. Salvant, G. Valentino
CERN, Geneva, Switzerland

The CMS-TOTEM Precision Proton Spectrometer (CT-PPS) at the LHC IP5 aims at exploring diffractive physics at high luminosity in standard LHC fills. It is based on 14 Roman Pots (RPs), designed to host tracking and time-of-flight detectors for measuring the kinematics of leading protons. To reach the physics goals, the RPs will finally have to approach the beams to distances of 15 beam σs (i.e. ~1.5 mm) or closer. After problems with showers and impedance heating in first high-luminosity RP insertions in 2012, the LS1 of LHC was used for upgrades in view of impedance minimisation and for adding new collimators to intercept RP-induced showers. In 2015 the effectiveness of these improvements was shown by successfully inserting the RPs in all LHC beam intensity steps to a first-phase distance of ~25 σs. This contribution reviews the measurements of debris showers and impedance effects, i.e. the data from Beam Loss Monitors, beam vacuum gauges and temperature sensors. The dependences of the observables on the luminosity are shown. Extrapolations to L=10³⁴ cm^-2 s^-1 and smaller distances to the beam do not indicate any fundamental problems. The plans for 2016 are outlined.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW021

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WEPMR038

Frequency Tuning for a DQW Crab Cavity

cavity, operation, simulation, SRF

2357

S. Verdú-Andrés, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA
K. Artoos, R. Calaga, O. Capatina, R. Leuxe, C. Zanoni
CERN, Geneva, Switzerland
I. Ben-Zvi
Stony Brook University, Stony Brook, USA

Funding: Work supported by US DOE via BSA LLC contract No.DE-AC02-98CH10886, the US LARP program, US DOE contract No. DE-AC02-05CH1123 (NERSC resources) and by HiLumi project.
The nominal operating frequency for the HL-LHC crab cavities is 400.79 MHz within a bandwidth of ±60kHz. Attaining the required cavity tune implies a good understanding of all the processes that influence the cavity frequency from the moment when the cavity parts are being fabricated until the cavity is installed and under operation. Different tuning options will be available for the DQW crab cavity of LHC. This paper details the different steps in the cavity fabrication and preparation that may introduce a shift in the cavity frequency and introduces the different tuning methods foreseen to bring the cavity frequency to meet the specifications.

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WEPMR058

Survey and Alignment for Taiwan Photon Source Storage Ring

survey, storage-ring, network, alignment

2405

W.Y. Lai, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, C.J. Lin, S.Y. Perng, C.W. Tsai, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is a 3 Gev synchrotron light source located in Hsinchu, Taiwan. The commissioning of the beam began on December 2014, and the phase 1 stored current of 100mA was achieved on March 2015. Then the installation and alignment of insertion device were complete during the shutdown from April to July, and also the scheduled maintenance of survey control points was complete in the meantime. This report presents survey alignment results and experience of the TPS .

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WEPMW006

First Design of a Proton Collimation System for 50 TeV FCC-hh

collimation, betatron, collider, proton

2423

M. Fiascaris, R. Bruce, D. Mirarchi, S. Redaelli
CERN, Geneva, Switzerland

We present studies aimed at defining a first conceptual solution for a collimation system for the hadron-hadron option for the Future Circular Collider (FCC-hh). The baseline collimation layout is based on the scaling of the present LHC collimation system to the FCC-hh energy. It currently includes a dedicated betatron cleaning insertion as well as collimators in the experimental insertions to protect the inner triplets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at top energy taking into account mechanical and optics imperfections. Based on these studies the collimator settings needed to protect the machine are defined. The performance of the collimation system is then assessed with particle tracking simulation tools assuming a perfect machine.

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WEPMW030

Cleaning Performance of the Collimation System of the High Luminosity Large Hadron Collider

collimation, ion, luminosity, simulation

2494

D. Mirarchi, A. Bertarelli, R. Bruce, F. Cerutti, P.D. Hermes, A. Lechner, A. Mereghetti, E. Quaranta, S. Redaelli
CERN, Geneva, Switzerland
R.B. Appleby
UMAN, Manchester, United Kingdom
H. Garcia Morales, R. Kwee-Hinzmann
Royal Holloway, University of London, Surrey, United Kingdom

Different upgrades of the LHC will be carried out in the framework of the High Luminosity project (HL-LHC), where the total stored energy in the machine will increase up to about 700 MJ. This unprecedented stored energy poses serious challenges for the collimation system, which was designed to handle safely up to about 360 MJ. In this paper the baseline collimation layout for HL-LHC is described, with main focus on upgrades related to the cleaning of halo and physics debris, and its expected performance is discussed. The main upgrade items include the presence of new collimators in the dispersion suppressor of the betatron cleaning insertion installed between two 11 T dipoles, and two additional collimators for an improved local protection of triplet magnets. Thus, optimized settings for the entire and upgraded collimation chain were conceived and are shown here together with the resulting cleaning performance. Moreover, the cleaning performance taking into account crab cavities it is also discussed.

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WEPMY038

Optimization of C-band RF Input Coupler as a Mode Converter for 20-K Cryocooled Photocathode RF Gun

cavity, gun, coupling, simulation

2638

T. Tanaka, M. Inagaki, R. Nagashima, K. Nakao, K. Nogami, T. Sakai, K. Takatsuka
LEBRA, Funabashi, Japan
M.K. Fukuda, T. Takatomi, N. Terunuma, J. Urakawa, M. Yoshida
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

Funding: Work supported by the Photon and Quantum Basic Research Coordinated Development Program of the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT).
Development of a cryocooled 2.6-cell C-band photocathode RF gun has been conducted at Nihon University in collaboration with KEK. An RF mode converter from square TE10 to circular TM01 mode has been employed as an RF input coupler that has a coupling coefficient of approximately 20 at 20 K to the 2.6-cell accelerating structure. In the previous design, the circular waveguide in the mode converter formed part of the accelerating cavity. After the cold test of the cavity completed in 2014, the coupler design was modified to work as a pure mode converter with a VSWR of 1 at 5712 MHz. From the design simulation using CST-STUDIO, the insertion loss in the converter is 0.2 %. The TM010 and TM011 modes excited in the circular waveguide were separated by several ten MHz from the accelerating frequency. The simulation has suggested that the amplitude of the transverse electric filed on the axis in the circular waveguide is reduced to approximately 2 % of that in the longitudinal direction.

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WEPOW018

Elettra Status and Upgrades

emittance, operation, insertion-device, wiggler

2864

E. Karantzoulis, A. Carniel, S. Krecic, C. P. Pasotti
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the possible future upgrades especially concerning the next ultra low emittance light source Elettra2.0.

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WEPOW046

Status of the Front Ends Project at MAXIV

storage-ring, radiation, vacuum, insertion-device

2947

A. Bartalesi, Y. Cerenius
MAX IV Laboratory, Lund University, Lund, Sweden
S. Forcat Oller
SLAC, Menlo Park, California, USA

The MAX IV laboratory is a Swedish national laboratory for synchrotron radiation hosted by the Lund University. It will operate two storage rings to produce synchrotron light of very high intensity and quality over a broad wavelength range. A linear accelerator will feed these storage rings in topping up mode as well as serve as an electron source for a short pulse facility built on its extension. The storage rings have different sizes and operates at different energies: the MAX IV 1.5 GeV ring has 12 straight sections optimized for soft x-rays; while the MAX IV 3.0 GeV ring, has 20 straight sections, optimized for harder x-rays. In the initial stage of the project, five beamlines are foreseen to operate on the 3 GeV storage ring and an additional five on the 1.5 GeV ring. Each beamline requires a front end to interface the different characteristics in terms of vacuum level, heat loads, radiation safety, beam size and position, with respect to the storage ring. This paper describes the status of the different Front Ends project at MAXIV.

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THEA01

Learn to Read Korean: An Introduction to the Hangul Alphabet

factory, ion, site, distributed

3207

Z. Handel
University of Washington, Seattle, Washington, USA

In the mid 15th century the Korean scholar-king Sejong invented Hangul, the native Korean alphabet. This was the beginning of a long process by which Hangul has gradually supplanted Chinese characters as Korea's primary script, a process which is still ongoing today. This presentation will introduce the historical and cultural background behind the invention of Hangul and describe the systematic linguistic principles on which it is based. The 1446 text that introduced Hangul proclaimed that it was so simple that "a wise man can master it in a morning, and even a stupid person can learn it in ten days." We will put this claim to the test by attempting to learn to read Korean during the 30-minute presentation.

Slides THEA01 [14.724 MB]

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THPMB023

Lattice Compensation of the Wiggler Effect in HLSII with Particle Swarm Optimization

wiggler, storage-ring, lattice, insertion-device

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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THPMR038

Non-Linear Errors in the Experimental Insertions of the LHC

multipole, coupling, dipole, dynamic-aperture

3472

E.H. Maclean, F.S. Carlier, M. Giovannozzi, A. Langner, S. Mönig, T. Persson, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland

Correction of nonlinear magnetic errors in low-β insertions can be of critical significance for the operation of a collider. This is expected to be of particular relevance to LHC Run II and the HL-LHC upgrade, as well as to future colliders such as the FCC. Current correction strategies for these accelerators have assumed it will be possible to calculate optimized local corrections through the insertions using a magnetic model of the errors. To test this assumption the nonlinear errors in the LHC experimental insertions have been examined via feed-down and amplitude detuning. It will be shown that while in some cases the magnetic measurements provide a sufficient description of the errors, in others large discrepancies exist which will require beam-based correction techniques.

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THPMR049

Minimization of Nonlinear Effects of Insertion Devices at SPS Storage Ring

electron, wiggler, multipole, storage-ring

3515

P. Sunwong, P. Klysubun, S. Kongtawong, S. Krainara, T. Pulampong, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand
T. Pulampong
JAI, Oxford, United Kingdom

Funding: Synchrotron Light Research Institute PO. Box 93 Nakhon Ratchasima 30000 Thailand
Nonlinear effects of insertion devices were studied for the Siam Photon Source (SPS) storage ring. Despite the fact that shimming technique was used to minimize the nonlinear components of magnetic field integral arising from random errors, the nonlinear dynamics effects still remain. It was found that calculated dynamic field integrals are largest in the 2.2 T Hybrid Multipole Wiggler (MPW). Dynamics effects of insertion devices are attributed to the wiggling trajectory of electron in the region of magnetic field roll-off due to finite pole width. For better and more effective operation of the SPS storage ring, multipole components of the dynamic field integral in the MPW have to be further reduced.

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THPOW046

Status of Insertion Device Measurement Systems at MAX IV Laboratory

insertion-device, controls, vacuum, undulator

4047

M. Ebbeni, H. Tarawneh, A. Thiel
MAX IV Laboratory, Lund University, Lund, Sweden

An insertion device lab was setup at MAX IV Laboratory and the production of insertion devices, mainly out-of-vacuum is ongoing and aided by new magnetic measurement systems. A new 5.5 m long Hall probe bench is used for field map measurements and a new hybrid flip coil and stretch wire system will be used for field integrals of full devices as well as individual magnet blocks characterisation. This paper describes these magnetic measurement systems and their achieved and expected performance.

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