IPAC2016 - List of Keywords (pick-up)

Paper	Title	Other Keywords	Page
MOPMB058	Bunch Arrival Time Monitor Test at PAL-XFEL ITF	LLRF, cavity, simulation, resonance	223
	J.H. Hong, J.H. Han, C. Kim, H. Yang PAL, Pohang, Kyungbuk, Republic of Korea
	Femtosecond resolution electron bunch arrival time monitor (BAM) will be required for the beam-based RF phase feedback during PAL-XFEL operation. Two S-band cavity-type BAMs were manufactured for the test at the PAL-XFEL injector test facility (ITF). The resonance frequencies of the cavities are 2856 MHz and 2826.25 MHz. Electron beam induced signal from the cavities was digitized using a low level RF (LLRF) module. In this paper, the resolution of these cavities are analyzed and a possible improvement for better resolution are discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB058
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MOPMB060	Upgrade of the LHC Schottky Monitor, Operational Experience and First Results	proton, ion, emittance, injection	226
	M. Betz, O.R. Jones, T. Lefèvre, M. Wendt CERN, Geneva, Switzerland
	The LHC Schottky system allows the measurement of beam parameters such as tune and chromaticity in an entirely non-invasive way by extracting information from the statistical fluctuations in the incoherent motion of particles. The system was commissioned in 2011 and provided satisfactory beam-parameter measurements during LHC run 1 for lead-ions. However, for protons its usability was substantially limited due to strong interfering signals originating from the coherent motion of the particle bunch. The system has recently been upgraded with optimized travelling-wave pick-ups and an improved 4.8~GHz microwave signal path, with the front-end and the triple down-mixing chain optimized to reduce coherent signals. Design and operational aspects for the complete system are shown and the results from measurements with LHC beams in Run II are presented and discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB060
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MOPMR002	Bunch by Bunch Position Measurement and Analysis at PLS-II	injection, kicker, operation, betatron	232
	J. Lee, M.-H. Chun, I. Hwang, D.T. Kim, G. Kim, T.-Y. Lee, D.C. Shin, S. Shin PAL, Pohang, Republic of Korea
	Beam dynamic phenomena described by bunch-by-bunch motion are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam position related to different dynamical mechanisms are a useful information to accelerator optimization. In PLS-II, 20 GHz sampling oscilloscope synchronized with injection event (or triggered by beam loss signal) is used to measure direct bunch by bunch motion. Based on the measured data, the principal component analysis had been performed to get the insight into beam dynamic phenomena such as couple bunch instability and beam oscillation due to kicker leakage. In this paper, we will describe the measurement method and the result of analysis for coupled bunch instability.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR002
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MOPMR014	Beam Diagnostics Overview for Collector Ring at FAIR	diagnostics, ion, antiproton, injection	255
	Yu. A. Rogovsky, E.A. Bekhtenev, M.I. Bryzgunov, O.I. Meshkov, D.B. Shwartz BINP SB RAS, Novosibirsk, Russia E.A. Bekhtenev, Yu. A. Rogovsky, D.B. Shwartz NSU, Novosibirsk, Russia O. Chorniy GSI, Darmstadt, Germany
	The Collector Ring (CR) is a dedicated storage ring in the FAIR project, where the main emphasis is laid on the effective stochastic precooling of intense secondary beams of stable ions, rare isotopes or antiprotons. A complex operation scheme with several types of operational cycles with beams in CR starting from injection, RF gymnastics, stochastic cooling then, and finishing to extraction is foreseen. Beam parameters changes significantly during the cycles. This demands an exceptional high dynamic range for the beam instrumentation. Non-destructive methods are mandatory for high currents as well as for the low current secondary beams due to the low repetition rate. Precise measurements of all beam parameters and automatic steering with short response time are required due to the necessary exploitation of the full ring acceptances. An overview of the challenges and solutions for various diagnostic installations will be given.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR014
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MOPMR019	Beam Tests of a Prototype Stripline Beam Position Monitoring System for the Drive Beam of the CLIC Two-beam Module at CTF3	electronics, impedance, vacuum, operation	270
	A. Benot-Morell, A. Faus-Golfe IFIC, Valencia, Spain A. Benot-Morell, M. Wendt CERN, Geneva, Switzerland A. Faus-Golfe LAL, Orsay, France J.M. Nappa, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France
	Funding: MINECO contract no. FPA2013-47883-C2-1-P. CLIC Collaboration Agreement, contract no. KE2638/BE. FNRA contract no. ANR-11-IDEX-0003-02. In collaboration with LAPP and IFIC, two units of a prototype stripline Beam Position Monitor (BPM) for the CLIC Drive Beam (DB), and its associated readout electronics have been successfully installed and tested in the Two-Beam-Module (TBM) at the CLIC Test Facility 3 (CTF3) at CERN. This paper gives a short overview of the BPM system and presents the performance measured under different Drive Beam configurations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR019
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MOPMR038	Design and Simulation Studies of the Novel Beam Arrival Monitor Pickup at Daresbury Laboratory	impedance, simulation, laser, FEL	334
	A. Kalinin, S.P. Jamison, T.T. Thakker STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R. Apsimon, G. Burt, A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	We present the novel beam arrival monitor pickup design currently under construction at Daresbury Laboratory, Warrington, UK. The pickup consists of four flat electrodes in a transverse gap. CST Particle Studio simulations have been undertaken for the new pickup design as well as a pickup design from DESY, which is used as a reference for comparison. Simulation results have highlighted two advantages of the new pickup design over the DESY design; the signal bandwidth is 25 GHz, which is half that of the DESY design and the response slope is a factor of 1.6 greater. We discuss optimisation studies of the design parameters in order to maximise the response slope for bandwidths up to 50 GHz and present the final design of the pickup.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR038
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MOPMW032	Study of RF Breakdown in 805MHz Pillbox Modular Cavity in Strong Magnetic Field	cavity, operation, radiation, site	466
	A.V. Kochemirovskiy University of Chicago, Chicago, Illinois, USA D.L. Bowring, A. Moretti, K. Yonehara Fermilab, Batavia, Illinois, USA B.T. Freemire IIT, Chicago, Illinois, USA Y. Torun Illinois Institute of Technology, Chicago, Illlinois, USA
	RF breakdown has a negative impact on a cavity's performance, especially with the presence of strong magnetic fields. This issue can arise in designs of muon ionization cooling channel, RF guns, klystrons and in many other applications. The MuCool Test Area at Fermilab is the facility that allows us to study the effects of static magnetic field on RF cavity operation. As a part of this research program, we have tested an 805MHz pillbox "modular" cavity in strong external magnetic fields. The design of the cavity allowed for a better control over sources of systematic error. "Modular" structure of the cavity enables easy dismounting of the endplates to perform inspection of inner surfaces after each run as well as swapping endplates to study the effects of various materials on breakdown phenomenon. Coupler design ensures maximum electric field enhancement on cavity axis, thus reducing breakdown probability in the coupler region. The results and analysis from high-power runs with zero and non-zero external magnetic fields will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW032
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TUPOW005	Update on Third Harmonic XFEL Activities at INFN LASA	cavity, HOM, operation, diagnostics	1751
	D. Sertore, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy C.G. Maiano DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	After the successful installation and beam operation of the first batch of 3.9 GHz cavities into the XFEL Third Harmonic Injector Module, ten more cavities have been tested and delivered to DESY to be assembled into a spare cryomodule. In this paper, we report on the activities related to the cavities fabrication, treatment and vertical testing at INFN LASA.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW005
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WEYB01	Diagnostic Systems of the PAL-XFEL	target, electron, electronics, diagnostics	2091
	C. Kim, S.Y. Baek, H. J. Choi, J.H. Hong, H.-S. Kang, G. Kim, J.H. Kim, I.S. Ko, S.J. Lee, G. Mun, B.G. Oh, B.R. Park, D.C. Shin, H. Yang PAL, Pohang, Kyungbuk, Republic of Korea
	The Pohang Accelerator Laboratory (PAL) started an x-ray free electron laser project (PAL-XFEL) in 2011. The construction was finished at the end of 2015 and the commissioning is planned from the beginning of 2016. In the PAL-XFEL, an electron beam with 200 pC will be generated from a photocathode RF gun and will be accelerated to 10 GeV by using a linear accelerator. The electron beam will pass through undulator section to produce hard X-ray radiation. For the successful commissioning and beam operation, various kinds of instruments were prepared.
	Slides WEYB01 [11.770 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEYB01
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WEOBB02	Status of Wakefield Monitor Experiments at the CLIC Test Facility	detector, emittance, experiment, electron	2099
	R.L. Lillestøl, E. Adli, J. Pfingstner University of Oslo, Oslo, Norway N. Aftab, S. Javeed PINSTECH, Islamabad, Pakistan R. Corsini, S. Döbert, W. Farabolini, A. Grudiev, W. Wuensch CERN, Geneva, Switzerland
	For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.
	Slides WEOBB02 [2.928 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBB02
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WEPMB003	Design of the HWR Cavities for SARAF	cavity, cryomodule, linac, simulation	2119
	G. Ferrand, L. Boudjaoui, D. Chirpaz-Cerbat, P. Hardy, F. Leseigneur, C. Madec, N. Misiara, N. Pichoff CEA/IRFU, Gif-sur-Yvette, France
	CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40 MeV. The SCL consists in 4 cryomodules. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.09) at 176 MHz. The last two identical cryomodule will host 7 HWR high-beta cavities (β = 0.18) at 176 MHz. Low-beta and high beta cavities have been optimized to limit electric and magnetic peak fields in the cavity, and to minimize the dissipated power. Manufacturing constraints and helium cooling were taken into consideration to minimize the risk during manufacturing and operation. Preliminary mechanical studies of the cavity and of the tuning system, as well as preliminary studies of the couplers and pick-up antennas were carried out. This work will be presented in this poster.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB003
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WEPMB006	XFEL Couplers RF Conditioning at LAL	vacuum, electron, site, controls	2125
	H. Guler, A. Gallas, W. Kaabi, D.J.M. Le Pinvidic, C. Magueur, M. Oublaid, A. Thiebault, A. Verguet LAL, Orsay, France
	The industrialization and the RF conditioning of 800 power couplers for the European XFEL have been performed by LAL-Orsay from fall 2013 to spring 2016. LAL laboratory has in charge the industrial monitoring, the quality control and the RF conditioning of the couplers fabricated by two different suppliers. It was the first experience of coupler production at such scale. The faced challenges, the different issues, and the lessons learned during the mass production will be reported. And finally the huge amount of RF conditioning data will be shown as one of key point on the conditioning process.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB006
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WEPMB050	RF Test of ESS Superconducting Spoke Cavities at Uppsala University	cavity, resonance, radiation, controls	2227
	H. Li, A.K. Bhattacharyya, V.A. Goryashko, L. Hermansson, R.J.M.Y. Ruber, R. Santiago Kern Uppsala University, Uppsala, Sweden N. Gandolfo, G. Olry IPN, Orsay, France
	The European Spallation Source (ESS) is an accelerator-driven neutron spallation source built in Sweden. It will deliver the first protons to a rotating tungsten target by 2019 and will reach the full 5 MW average beam power in the following years. The superconducting Spoke cavities are considered compact structures at low frequencies and having an excellent RF performance in both low and medium velocity regimes, therefore ESS will include a total of 26 double-spoke cavities. The testing of the double-spoke prototype cavity at high power has been conceded to Uppsala University, Sweden, where the Facility for Research Instrumentation and Accelerator development (FREIA) has been equipped with superconducting cavity test facility. A bare spoke cavity has been tested at the FREIA Laboratory with a self-exited loop at low power level to confirm its vertical test performance at IPNO. Similar test results as IPNO's previous test were obtained with FREIA system. In this paper we present the methods and preliminary study results of the cavity performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB050
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WEPMW034	First Operational Experience with Embedded Collimator BPMs in the LHC	alignment, embedded, collimation, interlocks	2510
	G. Valentino, G. Baud, R. Bruce, M. Gąsior, J. Olexa, S. Redaelli, A. Valloni, J. Wenninger CERN, Geneva, Switzerland
	During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also mean that margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts can be reduced, therefore increasing the beta-star and luminosity reach of the LHC. In this paper, the first operational results are presented, including a comparison with the standard alignment technique and a fill-to-fill analysis of the measured orbit in different machine modes in the first year of running after the shutdown.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW034
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WEPOY021	Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling	undulator, laser, radiation, kicker	3024
	M.B. Andorf, P. Piot Northern Illinois University, DeKalb, Illinois, USA V.A. Lebedev, P. Piot, J. Ruan Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359. Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator. A. Zholents, and M. Zolotorev. Proc. PAC'97, 1805 (1998).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY021
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WEPOY022	Light Optics for Optical Stochastic Cooling	undulator, radiation, kicker, electron	3028
	M.B. Andorf, P. Piot Northern Illinois University, DeKalb, Illinois, USA V.A. Lebedev, P. Piot, J. Ruan Fermilab, Batavia, Illinois, USA
	Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359. In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material. V. Lebedev, et al., Proc. COOL'15 (in press, 2015).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY022
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THPMW021	Performance of a Compensation Kicker Magnet for J-PARC Main Ring	timing, injection, kicker, proton	3588
	T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata KEK, Ibaraki, Japan K. Fan HUST, Wuhan, People's Republic of China
	Four lumped-type kicker magnets have been equipped in the J-PARC MR (Main Ring) to inject 8 proton bunches. To increase beam power, the bunch length will be increased up to 350 ns that will restricts the rise time of the injection kicker to be less than 250 ns. We have already developed a method to improve the rising time to 200 ns. However, two reflection pulses are appeared at the waveform tail, which will kick the circulating bunches and induce coherent oscillation leading to beam loss. To compensate reflection pulses, we decide to install two new lumped-type kicker magnets, which are excited independently making operation flexible. A ceramic vacuum duct with TiN coating is inserted in the compensation kickers. Magnetic field measurement and coupling impedance measurement have been carried. In this paper, the results of both these measurements and performance study using proton beam will be discussed. T.Sugimot et.al, "Upgrade of the Injection Kicker System for J-PARC Main Ring", MOPME069, IPAC14, Dresden, Germany, 2014.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW021
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THPOY036	A New Fast RF Trip Diagnostic System in SSRF	diagnostics, vacuum, cavity, klystron	4182
	S.J. Zhao, Q. Chang, H.T. Hou, Z. Li, K. Xu, W.Z. Zhang, Zh.G. Zhang, Y.B. Zhao, X. Zheng SINAP, Shanghai, People's Republic of China
	A RF trip diagnostic system is essential to find out the trip source when a trip happened. In this paper, a fast RF trip diagnostic system, in storage ring RF system of SSRF, is reported. This system includes a synchronous acquisition recorder to sampling the trip data and a trip server to analysis the data. The recorder has more than 100 channels and maximum sampling rate of each channel is up to 60 MSPS. High precision I/Q cards are designed to detect RF signals. Trip server has been developed to process the trip data.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY036
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Paper

Title

Other Keywords

Page

MOPMB058

Bunch Arrival Time Monitor Test at PAL-XFEL ITF

LLRF, cavity, simulation, resonance

223

J.H. Hong, J.H. Han, C. Kim, H. Yang
PAL, Pohang, Kyungbuk, Republic of Korea

Femtosecond resolution electron bunch arrival time monitor (BAM) will be required for the beam-based RF phase feedback during PAL-XFEL operation. Two S-band cavity-type BAMs were manufactured for the test at the PAL-XFEL injector test facility (ITF). The resonance frequencies of the cavities are 2856 MHz and 2826.25 MHz. Electron beam induced signal from the cavities was digitized using a low level RF (LLRF) module. In this paper, the resolution of these cavities are analyzed and a possible improvement for better resolution are discussed.

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MOPMB060

Upgrade of the LHC Schottky Monitor, Operational Experience and First Results

proton, ion, emittance, injection

226

M. Betz, O.R. Jones, T. Lefèvre, M. Wendt
CERN, Geneva, Switzerland

The LHC Schottky system allows the measurement of beam parameters such as tune and chromaticity in an entirely non-invasive way by extracting information from the statistical fluctuations in the incoherent motion of particles. The system was commissioned in 2011 and provided satisfactory beam-parameter measurements during LHC run 1 for lead-ions. However, for protons its usability was substantially limited due to strong interfering signals originating from the coherent motion of the particle bunch. The system has recently been upgraded with optimized travelling-wave pick-ups and an improved 4.8~GHz microwave signal path, with the front-end and the triple down-mixing chain optimized to reduce coherent signals. Design and operational aspects for the complete system are shown and the results from measurements with LHC beams in Run II are presented and discussed.

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MOPMR002

Bunch by Bunch Position Measurement and Analysis at PLS-II

injection, kicker, operation, betatron

232

J. Lee, M.-H. Chun, I. Hwang, D.T. Kim, G. Kim, T.-Y. Lee, D.C. Shin, S. Shin
PAL, Pohang, Republic of Korea

Beam dynamic phenomena described by bunch-by-bunch motion are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam position related to different dynamical mechanisms are a useful information to accelerator optimization. In PLS-II, 20 GHz sampling oscilloscope synchronized with injection event (or triggered by beam loss signal) is used to measure direct bunch by bunch motion. Based on the measured data, the principal component analysis had been performed to get the insight into beam dynamic phenomena such as couple bunch instability and beam oscillation due to kicker leakage. In this paper, we will describe the measurement method and the result of analysis for coupled bunch instability.

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MOPMR014

Beam Diagnostics Overview for Collector Ring at FAIR

diagnostics, ion, antiproton, injection

255

Yu. A. Rogovsky, E.A. Bekhtenev, M.I. Bryzgunov, O.I. Meshkov, D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia
E.A. Bekhtenev, Yu. A. Rogovsky, D.B. Shwartz
NSU, Novosibirsk, Russia
O. Chorniy
GSI, Darmstadt, Germany

The Collector Ring (CR) is a dedicated storage ring in the FAIR project, where the main emphasis is laid on the effective stochastic precooling of intense secondary beams of stable ions, rare isotopes or antiprotons. A complex operation scheme with several types of operational cycles with beams in CR starting from injection, RF gymnastics, stochastic cooling then, and finishing to extraction is foreseen. Beam parameters changes significantly during the cycles. This demands an exceptional high dynamic range for the beam instrumentation. Non-destructive methods are mandatory for high currents as well as for the low current secondary beams due to the low repetition rate. Precise measurements of all beam parameters and automatic steering with short response time are required due to the necessary exploitation of the full ring acceptances. An overview of the challenges and solutions for various diagnostic installations will be given.

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MOPMR019

Beam Tests of a Prototype Stripline Beam Position Monitoring System for the Drive Beam of the CLIC Two-beam Module at CTF3

electronics, impedance, vacuum, operation

270

A. Benot-Morell, A. Faus-Golfe
IFIC, Valencia, Spain
A. Benot-Morell, M. Wendt
CERN, Geneva, Switzerland
A. Faus-Golfe
LAL, Orsay, France
J.M. Nappa, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France

Funding: MINECO contract no. FPA2013-47883-C2-1-P. CLIC Collaboration Agreement, contract no. KE2638/BE. FNRA contract no. ANR-11-IDEX-0003-02.
In collaboration with LAPP and IFIC, two units of a prototype stripline Beam Position Monitor (BPM) for the CLIC Drive Beam (DB), and its associated readout electronics have been successfully installed and tested in the Two-Beam-Module (TBM) at the CLIC Test Facility 3 (CTF3) at CERN. This paper gives a short overview of the BPM system and presents the performance measured under different Drive Beam configurations.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR019

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MOPMR038

Design and Simulation Studies of the Novel Beam Arrival Monitor Pickup at Daresbury Laboratory

impedance, simulation, laser, FEL

334

A. Kalinin, S.P. Jamison, T.T. Thakker
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R. Apsimon, G. Burt, A.C. Dexter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

We present the novel beam arrival monitor pickup design currently under construction at Daresbury Laboratory, Warrington, UK. The pickup consists of four flat electrodes in a transverse gap. CST Particle Studio simulations have been undertaken for the new pickup design as well as a pickup design from DESY, which is used as a reference for comparison. Simulation results have highlighted two advantages of the new pickup design over the DESY design; the signal bandwidth is 25 GHz, which is half that of the DESY design and the response slope is a factor of 1.6 greater. We discuss optimisation studies of the design parameters in order to maximise the response slope for bandwidths up to 50 GHz and present the final design of the pickup.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR038

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MOPMW032

Study of RF Breakdown in 805MHz Pillbox Modular Cavity in Strong Magnetic Field

cavity, operation, radiation, site

466

A.V. Kochemirovskiy
University of Chicago, Chicago, Illinois, USA
D.L. Bowring, A. Moretti, K. Yonehara
Fermilab, Batavia, Illinois, USA
B.T. Freemire
IIT, Chicago, Illinois, USA
Y. Torun
Illinois Institute of Technology, Chicago, Illlinois, USA

RF breakdown has a negative impact on a cavity's performance, especially with the presence of strong magnetic fields. This issue can arise in designs of muon ionization cooling channel, RF guns, klystrons and in many other applications. The MuCool Test Area at Fermilab is the facility that allows us to study the effects of static magnetic field on RF cavity operation. As a part of this research program, we have tested an 805MHz pillbox "modular" cavity in strong external magnetic fields. The design of the cavity allowed for a better control over sources of systematic error. "Modular" structure of the cavity enables easy dismounting of the endplates to perform inspection of inner surfaces after each run as well as swapping endplates to study the effects of various materials on breakdown phenomenon. Coupler design ensures maximum electric field enhancement on cavity axis, thus reducing breakdown probability in the coupler region. The results and analysis from high-power runs with zero and non-zero external magnetic fields will be presented.

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TUPOW005

Update on Third Harmonic XFEL Activities at INFN LASA

cavity, HOM, operation, diagnostics

1751

D. Sertore, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
C.G. Maiano
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

After the successful installation and beam operation of the first batch of 3.9 GHz cavities into the XFEL Third Harmonic Injector Module, ten more cavities have been tested and delivered to DESY to be assembled into a spare cryomodule. In this paper, we report on the activities related to the cavities fabrication, treatment and vertical testing at INFN LASA.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW005

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WEYB01

Diagnostic Systems of the PAL-XFEL

target, electron, electronics, diagnostics

2091

C. Kim, S.Y. Baek, H. J. Choi, J.H. Hong, H.-S. Kang, G. Kim, J.H. Kim, I.S. Ko, S.J. Lee, G. Mun, B.G. Oh, B.R. Park, D.C. Shin, H. Yang
PAL, Pohang, Kyungbuk, Republic of Korea

The Pohang Accelerator Laboratory (PAL) started an x-ray free electron laser project (PAL-XFEL) in 2011. The construction was finished at the end of 2015 and the commissioning is planned from the beginning of 2016. In the PAL-XFEL, an electron beam with 200 pC will be generated from a photocathode RF gun and will be accelerated to 10 GeV by using a linear accelerator. The electron beam will pass through undulator section to produce hard X-ray radiation. For the successful commissioning and beam operation, various kinds of instruments were prepared.

Slides WEYB01 [11.770 MB]

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WEOBB02

Status of Wakefield Monitor Experiments at the CLIC Test Facility

detector, emittance, experiment, electron

2099

R.L. Lillestøl, E. Adli, J. Pfingstner
University of Oslo, Oslo, Norway
N. Aftab, S. Javeed
PINSTECH, Islamabad, Pakistan
R. Corsini, S. Döbert, W. Farabolini, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.

Slides WEOBB02 [2.928 MB]

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WEPMB003

Design of the HWR Cavities for SARAF

cavity, cryomodule, linac, simulation

2119

G. Ferrand, L. Boudjaoui, D. Chirpaz-Cerbat, P. Hardy, F. Leseigneur, C. Madec, N. Misiara, N. Pichoff
CEA/IRFU, Gif-sur-Yvette, France

CEA is committed to delivering a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3 MeV to 35 MeV or deuterons from 2.6 MeV to 40 MeV. The SCL consists in 4 cryomodules. The first two identical cryomodules host 6 half-wave resonator (HWR) low beta cavities (β = 0.09) at 176 MHz. The last two identical cryomodule will host 7 HWR high-beta cavities (β = 0.18) at 176 MHz. Low-beta and high beta cavities have been optimized to limit electric and magnetic peak fields in the cavity, and to minimize the dissipated power. Manufacturing constraints and helium cooling were taken into consideration to minimize the risk during manufacturing and operation. Preliminary mechanical studies of the cavity and of the tuning system, as well as preliminary studies of the couplers and pick-up antennas were carried out. This work will be presented in this poster.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB003

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WEPMB006

XFEL Couplers RF Conditioning at LAL

vacuum, electron, site, controls

2125

H. Guler, A. Gallas, W. Kaabi, D.J.M. Le Pinvidic, C. Magueur, M. Oublaid, A. Thiebault, A. Verguet
LAL, Orsay, France

The industrialization and the RF conditioning of 800 power couplers for the European XFEL have been performed by LAL-Orsay from fall 2013 to spring 2016. LAL laboratory has in charge the industrial monitoring, the quality control and the RF conditioning of the couplers fabricated by two different suppliers. It was the first experience of coupler production at such scale. The faced challenges, the different issues, and the lessons learned during the mass production will be reported. And finally the huge amount of RF conditioning data will be shown as one of key point on the conditioning process.

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WEPMB050

RF Test of ESS Superconducting Spoke Cavities at Uppsala University

cavity, resonance, radiation, controls

2227

H. Li, A.K. Bhattacharyya, V.A. Goryashko, L. Hermansson, R.J.M.Y. Ruber, R. Santiago Kern
Uppsala University, Uppsala, Sweden
N. Gandolfo, G. Olry
IPN, Orsay, France

The European Spallation Source (ESS) is an accelerator-driven neutron spallation source built in Sweden. It will deliver the first protons to a rotating tungsten target by 2019 and will reach the full 5 MW average beam power in the following years. The superconducting Spoke cavities are considered compact structures at low frequencies and having an excellent RF performance in both low and medium velocity regimes, therefore ESS will include a total of 26 double-spoke cavities. The testing of the double-spoke prototype cavity at high power has been conceded to Uppsala University, Sweden, where the Facility for Research Instrumentation and Accelerator development (FREIA) has been equipped with superconducting cavity test facility. A bare spoke cavity has been tested at the FREIA Laboratory with a self-exited loop at low power level to confirm its vertical test performance at IPNO. Similar test results as IPNO's previous test were obtained with FREIA system. In this paper we present the methods and preliminary study results of the cavity performance.

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WEPMW034

First Operational Experience with Embedded Collimator BPMs in the LHC

alignment, embedded, collimation, interlocks

2510

G. Valentino, G. Baud, R. Bruce, M. Gąsior, J. Olexa, S. Redaelli, A. Valloni, J. Wenninger
CERN, Geneva, Switzerland

During Long Shutdown 1, 18 Large Hadron Collider (LHC) collimators were replaced with a new design, in which beam position monitor (BPM) pick-up buttons are embedded in the collimator jaws. The BPMs provide a direct measurement of the beam orbit at the collimators, and therefore can be used to align the collimators more quickly than using the standard technique which relies on feedback from beam losses. Online orbit measurements also mean that margins in the collimation hierarchy placed specifically to cater for unknown orbit drifts can be reduced, therefore increasing the beta-star and luminosity reach of the LHC. In this paper, the first operational results are presented, including a comparison with the standard alignment technique and a fill-to-fill analysis of the measured orbit in different machine modes in the first year of running after the shutdown.

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WEPOY021

Nonlinear Phase Distortion in a Ti:Sapphire Optical Amplifier for Optical Stochastic Cooling

undulator, laser, radiation, kicker

3024

M.B. Andorf, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
V.A. Lebedev, P. Piot, J. Ruan
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
Optical Stochastic Cooling (OSC) has been considered for future high-luminosity colliders as it offers much faster cooling time in comparison to the micro-wave stochastic cooling. The OSC technique relies on collecting and amplifying a broadband optical signal from a pickup undulator and feeding the amplified signal back to the beam. It creates a corrective kick in a kicker undulator. Owing to its superb gain qualities and broadband amplification features, Titanium:Sapphire medium has been considered as a gain medium for the optical amplifier (OA) needed in the OSC*. A limiting factor for any OA used in OSC is the possibility of nonlinear phase distortions. In this paper we experimentally measure phase distortions by inserting a single-pass OA into one leg of a Mach-Zehnder interferometer. The measurement results are used to estimate the reduction of the corrective kick a particle would receive due to these phase distortions in the kicker undulator.
* A. Zholents, and M. Zolotorev. Proc. PAC'97, 1805 (1998).

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WEPOY022

Light Optics for Optical Stochastic Cooling

undulator, radiation, kicker, electron

3028

M.B. Andorf, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
V.A. Lebedev, P. Piot, J. Ruan
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the US DOE under contract DE-SC0013761 with Northern Illinois University. Fermilab is operated by the Fermi Research Alliance LLC under US DOE contract DE-AC02-07CH11359.
In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.
* V. Lebedev, et al., Proc. COOL'15 (in press, 2015).

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THPMW021

Performance of a Compensation Kicker Magnet for J-PARC Main Ring

timing, injection, kicker, proton

3588

T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People's Republic of China

Four lumped-type kicker magnets have been equipped in the J-PARC MR (Main Ring) to inject 8 proton bunches. To increase beam power, the bunch length will be increased up to 350 ns that will restricts the rise time of the injection kicker to be less than 250 ns. We have already developed a method to improve the rising time to 200 ns*. However, two reflection pulses are appeared at the waveform tail, which will kick the circulating bunches and induce coherent oscillation leading to beam loss. To compensate reflection pulses, we decide to install two new lumped-type kicker magnets, which are excited independently making operation flexible. A ceramic vacuum duct with TiN coating is inserted in the compensation kickers. Magnetic field measurement and coupling impedance measurement have been carried. In this paper, the results of both these measurements and performance study using proton beam will be discussed.
* T.Sugimot et.al, "Upgrade of the Injection Kicker System for J-PARC Main Ring", MOPME069, IPAC14, Dresden, Germany, 2014.

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THPOY036

A New Fast RF Trip Diagnostic System in SSRF

diagnostics, vacuum, cavity, klystron

4182

S.J. Zhao, Q. Chang, H.T. Hou, Z. Li, K. Xu, W.Z. Zhang, Zh.G. Zhang, Y.B. Zhao, X. Zheng
SINAP, Shanghai, People's Republic of China

A RF trip diagnostic system is essential to find out the trip source when a trip happened. In this paper, a fast RF trip diagnostic system, in storage ring RF system of SSRF, is reported. This system includes a synchronous acquisition recorder to sampling the trip data and a trip server to analysis the data. The recorder has more than 100 channels and maximum sampling rate of each channel is up to 60 MSPS. High precision I/Q cards are designed to detect RF signals. Trip server has been developed to process the trip data.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY036

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