IPAC2014 - List of Keywords (pick-up)

Paper	Title	Other Keywords	Page
MOPME001	Commissioning of the Double Electrostatic Storage Ring DESIREE	ion, experiment, storage-ring, injection	373
	A. Källberg, M. Björkhage, M. Blom, E. Bäckström, H. Cederquist, O.M. Hole, M. Kaminska, P. Löfgren, S. Mannervik, R. Nascimento, P. Reinhed, H.T. Schmidt, A. Simonsson Stockholm University, Stockholm, Sweden S. Rosén Stockholm University, Department of Physics, Stockholm, Sweden
	DESIREE, the double electrostatic storage rings in Stockholm, is now commissioned and used for experiments. The two 9 m circumference storage rings, which are constructed inside a double walled cryostat, are now cooled to 13 K and routinely used for storage of both negative and positive ions with lifetimes of several minutes. The main properties of DESIREE are presented as well as results from the commissioning and the first experiments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME001
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MOPRI067	Beam Cooling Systems and Activities at GSI and FAIR	electron, experiment, ion, antiproton	757
	C. Dimopoulou GSI, Darmstadt, Germany
	Efficient and versatile beam cooling (electron and stochastic cooling) has been an indispensable ingredient for beam preparation and physics experiments at the GSI accelerator complex. The hot secondary beams emerging from the production targets can hardly be used, unless they are cooled. Beam stacking of low-abundant species relies on cooling. Cooling enables high-precision experiments with stored beams, counteracts the heating during internal target operation and controls decelerated beams. New challenges lie ahead within the FAIR project like (i) the ongoing integration downstream of the ESR of the low-energy CRYRING with its electron cooler, (ii) the developments for the demanding CR stochastic cooling system, (iii) the stacking scenarios with RF and stochastic cooling in the HESR/RESR. The function and parameters of the existing and future beam cooling systems are summarized. We report on the latest hardware developments as well as on improvements of the controls and operation software. Recent highlights and results from beam manipulations with cooling at GSI are shown. In focus are those benchmarking experiments, where the concepts for the new FAIR systems are verified. C. Dimopoulou on behalf of the GSI Beam Cooling Department, of the GSI Stored Beams Division and of the FAIR Project Team.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI067
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MOPRI080	Measurement of Beam Phase using Phase Probe at the NIRS-930 Cyclotron	acceleration, extraction, cyclotron, septum	794
	S. Hojo, K. Katagiri, M. Nakao, A. Noda, K. Noda, A. Sugiura NIRS, Chiba-shi, Japan T. Honma, A.K. Komiyama, T. Okada, Y. Takahashi AEC, Chiba, Japan
	The NIRS-930 cyclotron of the National Institute of Radiological Sciences (NIRS) has been used for production of short-lived radio-pharmaceuticals for PET, research of physics, developments of particle detectors in space, and so on. The NIRS-930 has twelve trim coils for generation of the isochronous fields. Until recently, currents of the twelve trim coils had been adjusted only by monitoring the beam intensity. In order to exactly produce the isochronous fields, a phase probe has been installed in the NIRS-930. Recent results of beam tests using the phase probe will be presented in the present work.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI080
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TUPRO013	Studies on Stochastic Cooling of Heavy Ions in the LHC	kicker, cavity, luminosity, ion	1030
	M. Schaumann, J.M. Jowett, B. Salvant, M. Wendt CERN, Geneva, Switzerland M. Blaskiewicz, S. Verdú-Andrés BNL, Upton, Long Island, New York, USA
	Future high luminosity heavy-ion operation of the LHC will be dominated by very rapid luminosity decay due to the large collision cross-section and, to a lesser extent, emittance growth from intra-beam scattering (IBS) due to the high bunch intensities. A stochastic cooling system could reduce the emittance far below its initial value and reduce the losses from debunching during collisions, allowing more of the initial beam intensity to be converted into integrated luminosity before the beams are dumped. We review the status of this proposal, system and hardware properties and potential locations for the equipment in the tunnel.
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TUPRO084	Magnetic Tuning of FLASH2 Undulators	undulator, multipole, quadrupole, radiation	1235
	O. Bilani, P. Neumann, A. Schöps, M. Tischer, S. Tripathi, P. Vagin, T. Vielitz DESY, Hamburg, Germany
	The present fixed-gap undulator system for FLASH1 and the new FLASH2 undulators will share the same electron beam accelerator, thus 12 variable gap undulators are needed in order to provide radiation of different wavelengths to both experimental halls independently. Each of the 12 devices has a length of 2.5m. The magnet structure with a period length of 31.4mm provides a maximum field of 0.96T with an effective K-parameter of 2.81 at minimum gap. Phase, vertical and horizontal trajectories have been tuned based on Hall probe and stretched wire measurements. Remaining multipoles were optimized with moderate gap dependence by using magic fingers. At some magnet structures, shims were placed to correct gap dependent field integrals. All undulators have an rms vertical and horizontal trajectory flatness <6Tmm2 for all gaps corresponding to an rms trajectory roughness (at 1GeV) along the structure of ~2um. The rms phase error is below 2° over the entire gap range.
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TUPRI085	Development of a 4 GS/s Intra-bunch Instability Control System for the SPS - Next Steps	controls, feedback, kicker, simulation	1766
	J.D. Fox, J.M. Cesaratto, J.E. Dusatko, K.M. Pollock, C.H. Rivetta, O. Turgut SLAC, Menlo Park, California, USA S. De Santis LBNL, Berkeley, California, USA W. Höfle, G. Kotzian, U. Wehrle CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP). We present the expanded system architecture in development for the control of intra-bunch instabilities in the SPS. Earlier efforts concentrated on validating the performance of a single-bunch demonstration processor. This minimal system was successfully commissioned at the SPS just prior to the LS1 shutdown. The architecture is now in expansion for more complex functionality, specifically multi-bunch control, control during energy ramps, and the expansion of the system front-end dynamic range with more sophisticated orbit offset techniques. Two designs of wideband kicker are being developed for installation and evaluation with the beam. With these GHz bandwidth devices and new RF amplifiers we anticipate being able to excite and control internal motion of the beam consistent with modes expected for Ecloud and TMCI effects. We highlight the expanded features, and present strategies for verifying the behavior of the beam-feedback system in the next series of machine measurements planned after the LS1 shutdown.
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WEPRI099	Testing of a Single 11 T Nb3Sn Dipole Coil Using a Dipole Mirror Structure	dipole, quadrupole, target, instrumentation	2728
	A.V. Zlobin, N. Andreev, E.Z. Barzi, G. Chlachidze, V.V. Kashikhin, A. Nobrega, I. Novitski, D. Turrioni Fermilab, Batavia, Illinois, USA M. Karppinen, D. Smekens CERN, Geneva, Switzerland
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and European Commission under FP7 project HiLumi LHC, GA no.284404 FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC. To optimize coil design parameters and fabrication process and study coil performance, a series of 1 m long dipole coils is being fabricated. One of the short coils has been tested using a dipole mirror structure. This paper describes the dipole mirror magnetic and mechanical designs, and reports coil parameters and test results.
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THPRO021	Results Produced after Measuring PAL-ITF Beam Diagnostic Instruments	diagnostics, controls, laser, klystron	2903
	H. J. Choi, M.S. Chae, J.H. Hong, H.-S. Kang, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) built a PAL-ITF at the end of 2012 to successfully complete PAL-XFEL in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. An ICT and a Turbo-ICT were installed in the PAL-ITF. A Faraday Cup is installed at the end of the linear accelerator. These days, the quantity of electric charge occasionally is measured using a BPM Sum value. This paper focuses on the processes and results of electric charge quantity measurements using ICT, Turbo-ICT, FC and BPM. The PAL-ITF is equipped with Stripline-BPM. It is important to find a way to minimize measurement errors that can appear in the process of installing or measuring the BPM. For this, PAL-ITF separately measured the BPM electrode sensitivity and minimized BPM measurement errors through generally calibrating BPM devices by applying Lambertson's Method. A plan was made to minimize BPM measurement errors through applying the BPM electrical calibration method for BPM devices to be used by the PAL-XFEL. This paper examines the processes for checking the performance of the S-BPM installed in the PAL-ITF and the results of its measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO021
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THPME022	Recent Progress of the SSC-LINAC RFQ	rfq, cavity, linac, operation	3265
	G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu PKU, Beijing, People's Republic of China H. Du, Y. He, P. Jiang, X.N. Li, Z.S. Li, J.X. Wu, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, X.H. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	Funding: NFSC(11079001) The project of SSC-LINAC RFQ has important progresses in the past year. The machine has been moved to the Institute of Modern Physics in the first season of 2013. The cavity measurement including tests of RF performance and field distribution is carried out again in the laboratory. The Q0 is 6440, and the unflatness of the electric field in longitudinal is ±2.5%. The results demonstrated a good agreement with simulation. The RF and beam commissioning of the RFQ has been carried out in the first half of 2014. The duty factor rose from 5% to CW gradually. By now, the cavity has been operated with 35 kW on CW mode. The measurement of the bremsstrahlung spectrum reveals that the 35 kW power is needed to generate the 70 kV inter-vane voltage. The beam transmission efficiency and energy spread has been obtained in beam commissioning by accelerating 16O⁵⁺ and 40Ar⁸⁺ beams. The efficiency of 40Ar⁸⁺ is as high as 94%, and the output energy is 142.78 keV/u. All the processes and results of the experiments will be discussed in details.
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THPME038	Low Power RF Characterization of ESS Bilbao RFQ Cold Model	rfq, dipole, cavity, quadrupole	3308
	N. Garmendia, I. Bustinduy, O. González, P.J. González, I. Madariaga, L. Muguira, J.L. Muñoz ESS Bilbao, Zamudio, Spain A.V. Vélez HZB, Berlin, Germany
	In order to test both the design and manufacturing procedures of the final ESS-Bilbao RFQ, a 1 meter long RFQ Cold Model, including a longitudinal vane modulation, has been manufactured in aluminium. Low power RF measurements have been performed to obtain the main figures of merit of the cavity, including: frequency spectrum, coupling and quality factors, tuning range, RF sealing effect and the accelerating field profile. The experimental and simulated results are explained and analyzed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME038
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THPME100	The Mechanical Design of the BPM Inter-tank Section for P-linac at FAIR	linac, cavity, proton, impedance	3474
	M.H. Almalki, R. M. Brodhage, P. Forck, W. Kaufmann, O.K. Kester, P. Kowina, T. Sieber GSI, Darmstadt, Germany M.H. Almalki, R. M. Brodhage, O.K. Kester IAP, Frankfurt am Main, Germany M.H. Almalki KACST, Riyadh, Kingdom of Saudi Arabia J. Balaguer CEA/IRFU, Gif-sur-Yvette, France P. Girardot, C.S. Simon CEA/DSM/IRFU, France
	At the planned Proton LINAC at the FAIR facility, four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the 30 m long FAIR p-LINAC. The LINAC comprises of crossbar H-mode (CH) cavity to accelerate a 70 mA proton beam up to 70 MeV at frequency of 325 MHz. At four locations, the BPMs will be an integral part of the inter-tank section between the CCH and CH cavities within an evacuated housing. As the BPM centre is only 48 mm apart from the upstream cavity boundary, the rf-background at the BPM position, generated by the cavity must be evaluated. In this paper the mechanical design of the BPM for the inter-tank section is presented and the rf-noise at the BPM location is discussed.
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THPME121	The Status of the Diagnostic System at the Cryogenic Storage Ring CSR	ion, storage-ring, diagnostics, injection	3521
	M. Grieser, A. Becker, K. Blaum, S. George, C. Krantz, S. Vogel, A. Wolf, R. von Hahn MPI-K, Heidelberg, Germany
	The cryogenic storage ring (CSR) at MPI für Kernphysik is an electrostatic storage ring for low velocity phase space cooled ion beams. Among other experiments cooling and storage of molecular ions in their rotational ground state is projected. The stored beam current will be in the range of 1 nA - 1 μA. The resulting low signal strengths on the beam position pickups, current monitors and Schottky monitor put strong demands on these diagnostics tools. Methods and systems were developed to measure the profile of the ion beam. In the paper a summary of the CSR diagnostics tools and diagnosis of the first stored ion beam will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME121
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THPME122	A SQUID-based Beam Current Monitor for FAIR	cryogenics, electronics, niobium, ion	3524
	R. Geithner, T. Stöhlker, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany F. Kurian, H. Reeg, M. Schwickert GSI, Darmstadt, Germany T. Stöhlker IOQ, Jena, Germany
	A Cryogenic Current Comparator (CCC) was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam current in the nA-range. The CCC was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. Therefore, the low temperature properties of ferromagnetic core materials used in the pick-up coil were investigated and different SQUID-systems were tested. In this contribution we present results of the completed Cryogenic Current Comparator for FAIR working in a laboratory environment, regarding the improvements in resolution and bandwidth due to the use of suitable ferromagnetic core materials and optimized SQUID-system components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME122
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THPME131	A Multi-conductor Transmission Line Model for the BPMs	impedance, beam-transport, induction, framework	3550
	T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	We have developed an accurate and efficient analysis method with a multi-conductor transmission line model for beam position monitors (BPMs). This method combines the two-dimensional electrostatic analysis including beams in the transverse plane and the transmission line analysis in the longitudinal direction. The loads are also included in the boundary condition of the transmission line analysis. Calculation of 2D electrostatic fields can be easily performed with the boundary element method. The BPM response to a beam is compared with that to a stretched wire.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME131
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THPME145	BPM Signal Channel Characterization Test based on TDR for HLS II Storage Ring	storage-ring, impedance, simulation, electron	3593
	J.J. Zheng, C. Cheng, P. Lu, Q. Luo, B.G. Sun, Y.L. Yang, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A new BPM system on the upgraded Hefei light source (HLSII) storage ring is installed. Before the machine commissioning, the BPM system should be carefully tested, such as the conductivity and integrity of BPM signal channels from button electrodes to digital beam position processors (pickups, cables and connectors). This paper presents an experience of signal channel test based on time domain reflection (TDR) for HLS II storage ring BPM system. Basing on the wave propagation method, an analytic expression for the signal from TDR on BPM signal channel is briefly introduced. The conductivity and integrity of the BPM signal channels can be verified by comparing the TDR waveform to theory signal. All the BPM signal channels are tested by the TDR in order to verify electronic characteristic and the usability. And some breakdowns are analysed and handled.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME145
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THPME176	CERN Antiproton Decelerator Beam Instrumentation for the ELENA Era	antiproton, operation, instrumentation, electron	3684
	M. Ludwig, L. Bojtár, M.F. Fernandes, M. Gąsior, L. Søby, G. Tranquille CERN, Geneva, Switzerland
	CERN is currently constructing an Extra Low ENergy Antiproton ring (ELENA), which will allow the further deceleration of antiprotons from the currently exploited Antiproton Decelerator (AD). In order to meet the challenges of ELENA the beam instrumentation systems of the CERN AD are being consolidated and upgraded. An updated controls architecture with a more flexible timing system needs to be adopted and obsolete systems must be replaced. This paper presents the status and plans for improved performance and measurement availability of the AD beam instrumentation with a decreased risk of failure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME176
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THPME182	Precise Instruments for Bunch Charge Measurement	resonance, impedance, monitoring, vacuum	3703
	A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	For the pulse charge q injected into a capacitor of a parallel resonating circuit, the oscillation voltage V on a series resistor R is V=qwRexp(wt/2Q)sin(wt–1/2Q), t>τ, where w is the resonance frequency, Q>>1 is the quality factor and τ<<1/w is the pulse length. Of the two main parameters, R is known, and w can be found directly from the signal above. The quality factor contribution is low, and its rough estimation is sufficient to retain voltage accuracy. The observations above open a possibility of precise bunch charge measurement. We describe a bunch charge monitor that is a cavity with a lump capacitor as a low impedance coaxial line connected to a gap in the vacuum pipe. An LC electronic circuit is also presented. It integrates the single bunch current delivered by a Faraday Cup, or a Wall Current Monitor, or a Fast Current Transformer. The circuit has w~30MHz, Q~20, and with a Faraday Cup, the lower range is 10pC/V and the noise floor is about 20fC. Several such circuits are in use on the VELA injector in Daresbury Laboratory.
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THPME186	Development of a BPM System using a Commercial FPGA Card and Digitizer Adaptor Module for FETS	FPGA, LabView, alignment, electronics	3716
	G.E. Boorman, S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom R.T.P. D'Arcy, S. Jolly UCL, London, United Kingdom S.R. Lawrie, A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	A series of beam position monitors (BPMs) will be installed at the Front End Test Stand (FETS) at RAL as part of the 3 MeV Medium Energy Beam Transport (MEBT). The BPMs analyse 2 ms long, 60 mA beam pulses delivered to the MEBT by a 324 MHz Radio Frequency Quadrupole (RFQ). Initial linearity and resolution measurements from the prototype button BPMs are shown. The development of the algorithm for the processing of the BPM signals using a commercial PXI-based FPGA card is discussed and initial measurements of the electronics and signal processing are presented. The test-rig used to characterise each BPM and further develop the processing algorithm is described. The position and phase are measured several times throughout the duration of each pulse, and the measurements are made available via an EPICS server.
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THPRI050	Calculation and Design of the Re-buncher Cavities for the LIPAc Deuteron Accelerator	cavity, vacuum, operation, beam-transport	3881
	D. Gavela, I. Podadera, F. Toral CIEMAT, Madrid, Spain
	Funding: This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project AIC-A-2011-0654 Two re-buncher cavities are necessary for the LIPAc (Linear IFMIF Prototype Accelerator), presently being built at Rokkasho (Japan). They are placed at the Medium Energy Beam Transport (MEBT) line to longitudinally focus a 5 MeV CW deuteron beam. Due to the strong space charge and the compactness of the beamline, the cavity has several space restrictions. In order to minimize the power loss, an IH-type cavity with 5 gaps was selected. It provides an effective voltage of 350 kV at 175 MHz with a power loss of 6.6 kW. First, electromagnetic calculations have been done with HFSS to compute the resonant frequency, the S-parameters, the electric and magnetic field maps, the power losses and the proper geometry for a magnetic input coupler and a pickup probe. Then, a mechanical Ansys model has been used to analyze the stresses and deformations due to vacuum, the cooling circuit and the temperature distribution, taking into account the power losses imported from the electromagnetic model. Finally, the fluid dynamics in the cooling circuits of the stems has been carefully studied.
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THPRI051	Fabrication and Tests of the Re-buncher Cavities for the LIPAc Deuteron Accelerator	cavity, vacuum, coupling, simulation	3884
	D. Gavela, P. Abramian, J. Calero, A. Guirao, J.L. Gutiérrez, E. Molina Marinas, I. Podadera, L. Sánchez, F. Toral CIEMAT, Madrid, Spain
	Funding: This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project AIC-A-2011-0654 Two re-buncher cavities will be installed at the Medium Energy Beam Transport (MEBT) of the LIPAc accelerator, presently being built at Rokkasho (Japan). They are IH-type cavities with 5 gaps and will provide an effective voltage of 350 kV at 175 MHz. The cavity consists of a cylindrical main body and two endplates in stainless steel with an internal copper coating. The stems and drift tubes are machined from bulk OFE copper. The fabrication techniques for the cooling pipes, the input coupler and the pick-up are presented. Material choices and fabrication process are discussed. The first re-buncher is already fabricated. RF low power tests have been made to measure resonant frequency, S-parameters and Q-factor before and after the copper plating. The electric field map has also been measured with the bead-pull method.
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THPRI071	Instrumentation for Characterizing 201-MHz MICE Cavity at Fermilab	cavity, vacuum, instrumentation, electron	3930
	M. Chung, D.L. Bowring, A. Moretti, R.J. Pasquinelli, D.W. Peterson, R.P. Schultz Fermilab, Batavia, Illinois, USA P.G. Lane, Y. Torun Illinois Institute of Technology, Chicago, Illinois, USA L. Somaschini INFN-Pisa, Pisa, Italy
	A 201-MHz single cavity module is installed in the Mucool Test Area (MTA) of Fermilab to test the performance of the cavity at the design parameters for the International Muon Ionization Cooling Experiment (MICE) particularly in multi-Tesla external magnetic fields. To monitor various aspects of the cavity and to understand detailed physics involved in RF breakdown and multipacting, numerous instrumentation is installed on the cavity module and also in the experimental hall, which includes thermocouples, infrared sensors, electron pickups, fiber light guides, and radiation detectors. In this paper, we will present details of each diagnostic and initial test results.
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THPRI077	Electric Field Enhancement Study using an L-band Photocathode Gun	cathode, gun, experiment, simulation	3946
	J.H. Shao, W. Gai ANL, Argonne, Illinois, USA H.B. Chen, J. Shi TUB, Beijing, People's Republic of China C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA F.Y. Wang, L. Xiao SLAC, Menlo Park, California, USA
	RF breakdown in high gradient accelerating structures is a fundamental problem that is still needed better understanding. Past studies have indicated that field emission, which is usually represented by electric field enhancement (i.e. β) produced from the Fowler-Nordheim plot, is strongly coupled to the breakdown problem. A controlled surface study using a high gradient L-band RF gun is being carried out. With a flat cathode, the maximum electric field on the surface reached 10³ MV/m. And electric field as high as 565 MV/m on the surface was achieved by a pin-shaped cathode. The field enhancement factor was measured at different surface field during the conditioning process. Initial results of the study are presented in this paper.
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Paper

Title

Other Keywords

Page

MOPME001

Commissioning of the Double Electrostatic Storage Ring DESIREE

ion, experiment, storage-ring, injection

373

A. Källberg, M. Björkhage, M. Blom, E. Bäckström, H. Cederquist, O.M. Hole, M. Kaminska, P. Löfgren, S. Mannervik, R. Nascimento, P. Reinhed, H.T. Schmidt, A. Simonsson
Stockholm University, Stockholm, Sweden
S. Rosén
Stockholm University, Department of Physics, Stockholm, Sweden

DESIREE, the double electrostatic storage rings in Stockholm, is now commissioned and used for experiments. The two 9 m circumference storage rings, which are constructed inside a double walled cryostat, are now cooled to 13 K and routinely used for storage of both negative and positive ions with lifetimes of several minutes. The main properties of DESIREE are presented as well as results from the commissioning and the first experiments.

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MOPRI067

Beam Cooling Systems and Activities at GSI and FAIR

electron, experiment, ion, antiproton

757

C. Dimopoulou
GSI, Darmstadt, Germany

Efficient and versatile beam cooling (electron and stochastic cooling) has been an indispensable ingredient for beam preparation and physics experiments at the GSI accelerator complex. The hot secondary beams emerging from the production targets can hardly be used, unless they are cooled. Beam stacking of low-abundant species relies on cooling. Cooling enables high-precision experiments with stored beams, counteracts the heating during internal target operation and controls decelerated beams. New challenges lie ahead within the FAIR project like (i) the ongoing integration downstream of the ESR of the low-energy CRYRING with its electron cooler, (ii) the developments for the demanding CR stochastic cooling system, (iii) the stacking scenarios with RF and stochastic cooling in the HESR/RESR. The function and parameters of the existing and future beam cooling systems are summarized. We report on the latest hardware developments as well as on improvements of the controls and operation software. Recent highlights and results from beam manipulations with cooling at GSI are shown. In focus are those benchmarking experiments, where the concepts for the new FAIR systems are verified.
C. Dimopoulou on behalf of the GSI Beam Cooling Department, of the GSI Stored Beams Division and of the FAIR Project Team.

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MOPRI080

Measurement of Beam Phase using Phase Probe at the NIRS-930 Cyclotron

acceleration, extraction, cyclotron, septum

794

S. Hojo, K. Katagiri, M. Nakao, A. Noda, K. Noda, A. Sugiura
NIRS, Chiba-shi, Japan
T. Honma, A.K. Komiyama, T. Okada, Y. Takahashi
AEC, Chiba, Japan

The NIRS-930 cyclotron of the National Institute of Radiological Sciences (NIRS) has been used for production of short-lived radio-pharmaceuticals for PET, research of physics, developments of particle detectors in space, and so on. The NIRS-930 has twelve trim coils for generation of the isochronous fields. Until recently, currents of the twelve trim coils had been adjusted only by monitoring the beam intensity. In order to exactly produce the isochronous fields, a phase probe has been installed in the NIRS-930. Recent results of beam tests using the phase probe will be presented in the present work.

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TUPRO013

Studies on Stochastic Cooling of Heavy Ions in the LHC

kicker, cavity, luminosity, ion

1030

M. Schaumann, J.M. Jowett, B. Salvant, M. Wendt
CERN, Geneva, Switzerland
M. Blaskiewicz, S. Verdú-Andrés
BNL, Upton, Long Island, New York, USA

Future high luminosity heavy-ion operation of the LHC will be dominated by very rapid luminosity decay due to the large collision cross-section and, to a lesser extent, emittance growth from intra-beam scattering (IBS) due to the high bunch intensities. A stochastic cooling system could reduce the emittance far below its initial value and reduce the losses from debunching during collisions, allowing more of the initial beam intensity to be converted into integrated luminosity before the beams are dumped. We review the status of this proposal, system and hardware properties and potential locations for the equipment in the tunnel.

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TUPRO084

Magnetic Tuning of FLASH2 Undulators

undulator, multipole, quadrupole, radiation

1235

O. Bilani, P. Neumann, A. Schöps, M. Tischer, S. Tripathi, P. Vagin, T. Vielitz
DESY, Hamburg, Germany

The present fixed-gap undulator system for FLASH1 and the new FLASH2 undulators will share the same electron beam accelerator, thus 12 variable gap undulators are needed in order to provide radiation of different wavelengths to both experimental halls independently. Each of the 12 devices has a length of 2.5m. The magnet structure with a period length of 31.4mm provides a maximum field of 0.96T with an effective K-parameter of 2.81 at minimum gap. Phase, vertical and horizontal trajectories have been tuned based on Hall probe and stretched wire measurements. Remaining multipoles were optimized with moderate gap dependence by using magic fingers. At some magnet structures, shims were placed to correct gap dependent field integrals. All undulators have an rms vertical and horizontal trajectory flatness <6Tmm2 for all gaps corresponding to an rms trajectory roughness (at 1GeV) along the structure of ~2um. The rms phase error is below 2° over the entire gap range.

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TUPRI085

Development of a 4 GS/s Intra-bunch Instability Control System for the SPS - Next Steps

controls, feedback, kicker, simulation

1766

J.D. Fox, J.M. Cesaratto, J.E. Dusatko, K.M. Pollock, C.H. Rivetta, O. Turgut
SLAC, Menlo Park, California, USA
S. De Santis
LBNL, Berkeley, California, USA
W. Höfle, G. Kotzian, U. Wehrle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP).
We present the expanded system architecture in development for the control of intra-bunch instabilities in the SPS. Earlier efforts concentrated on validating the performance of a single-bunch demonstration processor. This minimal system was successfully commissioned at the SPS just prior to the LS1 shutdown. The architecture is now in expansion for more complex functionality, specifically multi-bunch control, control during energy ramps, and the expansion of the system front-end dynamic range with more sophisticated orbit offset techniques. Two designs of wideband kicker are being developed for installation and evaluation with the beam. With these GHz bandwidth devices and new RF amplifiers we anticipate being able to excite and control internal motion of the beam consistent with modes expected for Ecloud and TMCI effects. We highlight the expanded features, and present strategies for verifying the behavior of the beam-feedback system in the next series of machine measurements planned after the LS1 shutdown.

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WEPRI099

Testing of a Single 11 T Nb3Sn Dipole Coil Using a Dipole Mirror Structure

dipole, quadrupole, target, instrumentation

2728

A.V. Zlobin, N. Andreev, E.Z. Barzi, G. Chlachidze, V.V. Kashikhin, A. Nobrega, I. Novitski, D. Turrioni
Fermilab, Batavia, Illinois, USA
M. Karppinen, D. Smekens
CERN, Geneva, Switzerland

Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and European Commission under FP7 project HiLumi LHC, GA no.284404
FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC. To optimize coil design parameters and fabrication process and study coil performance, a series of 1 m long dipole coils is being fabricated. One of the short coils has been tested using a dipole mirror structure. This paper describes the dipole mirror magnetic and mechanical designs, and reports coil parameters and test results.

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THPRO021

Results Produced after Measuring PAL-ITF Beam Diagnostic Instruments

diagnostics, controls, laser, klystron

2903

H. J. Choi, M.S. Chae, J.H. Hong, H.-S. Kang, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) built a PAL-ITF at the end of 2012 to successfully complete PAL-XFEL in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. An ICT and a Turbo-ICT were installed in the PAL-ITF. A Faraday Cup is installed at the end of the linear accelerator. These days, the quantity of electric charge occasionally is measured using a BPM Sum value. This paper focuses on the processes and results of electric charge quantity measurements using ICT, Turbo-ICT, FC and BPM. The PAL-ITF is equipped with Stripline-BPM. It is important to find a way to minimize measurement errors that can appear in the process of installing or measuring the BPM. For this, PAL-ITF separately measured the BPM electrode sensitivity and minimized BPM measurement errors through generally calibrating BPM devices by applying Lambertson's Method. A plan was made to minimize BPM measurement errors through applying the BPM electrical calibration method for BPM devices to be used by the PAL-XFEL. This paper examines the processes for checking the performance of the S-BPM installed in the PAL-ITF and the results of its measurements.

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THPME022

Recent Progress of the SSC-LINAC RFQ

rfq, cavity, linac, operation

3265

G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
PKU, Beijing, People's Republic of China
H. Du, Y. He, P. Jiang, X.N. Li, Z.S. Li, J.X. Wu, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, X.H. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: NFSC(11079001)
The project of SSC-LINAC RFQ has important progresses in the past year. The machine has been moved to the Institute of Modern Physics in the first season of 2013. The cavity measurement including tests of RF performance and field distribution is carried out again in the laboratory. The Q0 is 6440, and the unflatness of the electric field in longitudinal is ±2.5%. The results demonstrated a good agreement with simulation. The RF and beam commissioning of the RFQ has been carried out in the first half of 2014. The duty factor rose from 5% to CW gradually. By now, the cavity has been operated with 35 kW on CW mode. The measurement of the bremsstrahlung spectrum reveals that the 35 kW power is needed to generate the 70 kV inter-vane voltage. The beam transmission efficiency and energy spread has been obtained in beam commissioning by accelerating 16O⁵⁺ and 40Ar⁸⁺ beams. The efficiency of 40Ar⁸⁺ is as high as 94%, and the output energy is 142.78 keV/u. All the processes and results of the experiments will be discussed in details.

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THPME038

Low Power RF Characterization of ESS Bilbao RFQ Cold Model

rfq, dipole, cavity, quadrupole

3308

N. Garmendia, I. Bustinduy, O. González, P.J. González, I. Madariaga, L. Muguira, J.L. Muñoz
ESS Bilbao, Zamudio, Spain
A.V. Vélez
HZB, Berlin, Germany

In order to test both the design and manufacturing procedures of the final ESS-Bilbao RFQ, a 1 meter long RFQ Cold Model, including a longitudinal vane modulation, has been manufactured in aluminium. Low power RF measurements have been performed to obtain the main figures of merit of the cavity, including: frequency spectrum, coupling and quality factors, tuning range, RF sealing effect and the accelerating field profile. The experimental and simulated results are explained and analyzed.

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THPME100

The Mechanical Design of the BPM Inter-tank Section for P-linac at FAIR

linac, cavity, proton, impedance

3474

M.H. Almalki, R. M. Brodhage, P. Forck, W. Kaufmann, O.K. Kester, P. Kowina, T. Sieber
GSI, Darmstadt, Germany
M.H. Almalki, R. M. Brodhage, O.K. Kester
IAP, Frankfurt am Main, Germany
M.H. Almalki
KACST, Riyadh, Kingdom of Saudi Arabia
J. Balaguer
CEA/IRFU, Gif-sur-Yvette, France
P. Girardot, C.S. Simon
CEA/DSM/IRFU, France

At the planned Proton LINAC at the FAIR facility, four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the 30 m long FAIR p-LINAC. The LINAC comprises of crossbar H-mode (CH) cavity to accelerate a 70 mA proton beam up to 70 MeV at frequency of 325 MHz. At four locations, the BPMs will be an integral part of the inter-tank section between the CCH and CH cavities within an evacuated housing. As the BPM centre is only 48 mm apart from the upstream cavity boundary, the rf-background at the BPM position, generated by the cavity must be evaluated. In this paper the mechanical design of the BPM for the inter-tank section is presented and the rf-noise at the BPM location is discussed.

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THPME121

The Status of the Diagnostic System at the Cryogenic Storage Ring CSR

ion, storage-ring, diagnostics, injection

3521

M. Grieser, A. Becker, K. Blaum, S. George, C. Krantz, S. Vogel, A. Wolf, R. von Hahn
MPI-K, Heidelberg, Germany

The cryogenic storage ring (CSR) at MPI für Kernphysik is an electrostatic storage ring for low velocity phase space cooled ion beams. Among other experiments cooling and storage of molecular ions in their rotational ground state is projected. The stored beam current will be in the range of 1 nA - 1 μA. The resulting low signal strengths on the beam position pickups, current monitors and Schottky monitor put strong demands on these diagnostics tools. Methods and systems were developed to measure the profile of the ion beam. In the paper a summary of the CSR diagnostics tools and diagnosis of the first stored ion beam will be given.

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THPME122

A SQUID-based Beam Current Monitor for FAIR

cryogenics, electronics, niobium, ion

3524

R. Geithner, T. Stöhlker, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
F. Kurian, H. Reeg, M. Schwickert
GSI, Darmstadt, Germany
T. Stöhlker
IOQ, Jena, Germany

A Cryogenic Current Comparator (CCC) was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam current in the nA-range. The CCC was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. Therefore, the low temperature properties of ferromagnetic core materials used in the pick-up coil were investigated and different SQUID-systems were tested. In this contribution we present results of the completed Cryogenic Current Comparator for FAIR working in a laboratory environment, regarding the improvements in resolution and bandwidth due to the use of suitable ferromagnetic core materials and optimized SQUID-system components.

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THPME131

A Multi-conductor Transmission Line Model for the BPMs

impedance, beam-transport, induction, framework

3550

T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

We have developed an accurate and efficient analysis method with a multi-conductor transmission line model for beam position monitors (BPMs). This method combines the two-dimensional electrostatic analysis including beams in the transverse plane and the transmission line analysis in the longitudinal direction. The loads are also included in the boundary condition of the transmission line analysis. Calculation of 2D electrostatic fields can be easily performed with the boundary element method. The BPM response to a beam is compared with that to a stretched wire.

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THPME145

BPM Signal Channel Characterization Test based on TDR for HLS II Storage Ring

storage-ring, impedance, simulation, electron

3593

J.J. Zheng, C. Cheng, P. Lu, Q. Luo, B.G. Sun, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new BPM system on the upgraded Hefei light source (HLSII) storage ring is installed. Before the machine commissioning, the BPM system should be carefully tested, such as the conductivity and integrity of BPM signal channels from button electrodes to digital beam position processors (pickups, cables and connectors). This paper presents an experience of signal channel test based on time domain reflection (TDR) for HLS II storage ring BPM system. Basing on the wave propagation method, an analytic expression for the signal from TDR on BPM signal channel is briefly introduced. The conductivity and integrity of the BPM signal channels can be verified by comparing the TDR waveform to theory signal. All the BPM signal channels are tested by the TDR in order to verify electronic characteristic and the usability. And some breakdowns are analysed and handled.

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THPME176

CERN Antiproton Decelerator Beam Instrumentation for the ELENA Era

antiproton, operation, instrumentation, electron

3684

M. Ludwig, L. Bojtár, M.F. Fernandes, M. Gąsior, L. Søby, G. Tranquille
CERN, Geneva, Switzerland

CERN is currently constructing an Extra Low ENergy Antiproton ring (ELENA), which will allow the further deceleration of antiprotons from the currently exploited Antiproton Decelerator (AD). In order to meet the challenges of ELENA the beam instrumentation systems of the CERN AD are being consolidated and upgraded. An updated controls architecture with a more flexible timing system needs to be adopted and obsolete systems must be replaced. This paper presents the status and plans for improved performance and measurement availability of the AD beam instrumentation with a decreased risk of failure.

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THPME182

Precise Instruments for Bunch Charge Measurement

resonance, impedance, monitoring, vacuum

3703

A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

For the pulse charge q injected into a capacitor of a parallel resonating circuit, the oscillation voltage V on a series resistor R is V=qwRexp(wt/2Q)sin(wt–1/2Q), t>τ, where w is the resonance frequency, Q>>1 is the quality factor and τ<<1/w is the pulse length. Of the two main parameters, R is known, and w can be found directly from the signal above. The quality factor contribution is low, and its rough estimation is sufficient to retain voltage accuracy. The observations above open a possibility of precise bunch charge measurement. We describe a bunch charge monitor that is a cavity with a lump capacitor as a low impedance coaxial line connected to a gap in the vacuum pipe. An LC electronic circuit is also presented. It integrates the single bunch current delivered by a Faraday Cup, or a Wall Current Monitor, or a Fast Current Transformer. The circuit has w~30MHz, Q~20, and with a Faraday Cup, the lower range is 10pC/V and the noise floor is about 20fC. Several such circuits are in use on the VELA injector in Daresbury Laboratory.

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THPME186

Development of a BPM System using a Commercial FPGA Card and Digitizer Adaptor Module for FETS

FPGA, LabView, alignment, electronics

3716

G.E. Boorman, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
R.T.P. D'Arcy, S. Jolly
UCL, London, United Kingdom
S.R. Lawrie, A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A series of beam position monitors (BPMs) will be installed at the Front End Test Stand (FETS) at RAL as part of the 3 MeV Medium Energy Beam Transport (MEBT). The BPMs analyse 2 ms long, 60 mA beam pulses delivered to the MEBT by a 324 MHz Radio Frequency Quadrupole (RFQ). Initial linearity and resolution measurements from the prototype button BPMs are shown. The development of the algorithm for the processing of the BPM signals using a commercial PXI-based FPGA card is discussed and initial measurements of the electronics and signal processing are presented. The test-rig used to characterise each BPM and further develop the processing algorithm is described. The position and phase are measured several times throughout the duration of each pulse, and the measurements are made available via an EPICS server.

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THPRI050

Calculation and Design of the Re-buncher Cavities for the LIPAc Deuteron Accelerator

cavity, vacuum, operation, beam-transport

3881

D. Gavela, I. Podadera, F. Toral
CIEMAT, Madrid, Spain

Funding: This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project AIC-A-2011-0654
Two re-buncher cavities are necessary for the LIPAc (Linear IFMIF Prototype Accelerator), presently being built at Rokkasho (Japan). They are placed at the Medium Energy Beam Transport (MEBT) line to longitudinally focus a 5 MeV CW deuteron beam. Due to the strong space charge and the compactness of the beamline, the cavity has several space restrictions. In order to minimize the power loss, an IH-type cavity with 5 gaps was selected. It provides an effective voltage of 350 kV at 175 MHz with a power loss of 6.6 kW. First, electromagnetic calculations have been done with HFSS to compute the resonant frequency, the S-parameters, the electric and magnetic field maps, the power losses and the proper geometry for a magnetic input coupler and a pickup probe. Then, a mechanical Ansys model has been used to analyze the stresses and deformations due to vacuum, the cooling circuit and the temperature distribution, taking into account the power losses imported from the electromagnetic model. Finally, the fluid dynamics in the cooling circuits of the stems has been carefully studied.

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THPRI051

Fabrication and Tests of the Re-buncher Cavities for the LIPAc Deuteron Accelerator

cavity, vacuum, coupling, simulation

3884

D. Gavela, P. Abramian, J. Calero, A. Guirao, J.L. Gutiérrez, E. Molina Marinas, I. Podadera, L. Sánchez, F. Toral
CIEMAT, Madrid, Spain

Funding: This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under project AIC-A-2011-0654
Two re-buncher cavities will be installed at the Medium Energy Beam Transport (MEBT) of the LIPAc accelerator, presently being built at Rokkasho (Japan). They are IH-type cavities with 5 gaps and will provide an effective voltage of 350 kV at 175 MHz. The cavity consists of a cylindrical main body and two endplates in stainless steel with an internal copper coating. The stems and drift tubes are machined from bulk OFE copper. The fabrication techniques for the cooling pipes, the input coupler and the pick-up are presented. Material choices and fabrication process are discussed. The first re-buncher is already fabricated. RF low power tests have been made to measure resonant frequency, S-parameters and Q-factor before and after the copper plating. The electric field map has also been measured with the bead-pull method.

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THPRI071

Instrumentation for Characterizing 201-MHz MICE Cavity at Fermilab

cavity, vacuum, instrumentation, electron

3930

M. Chung, D.L. Bowring, A. Moretti, R.J. Pasquinelli, D.W. Peterson, R.P. Schultz
Fermilab, Batavia, Illinois, USA
P.G. Lane, Y. Torun
Illinois Institute of Technology, Chicago, Illinois, USA
L. Somaschini
INFN-Pisa, Pisa, Italy

A 201-MHz single cavity module is installed in the Mucool Test Area (MTA) of Fermilab to test the performance of the cavity at the design parameters for the International Muon Ionization Cooling Experiment (MICE) particularly in multi-Tesla external magnetic fields. To monitor various aspects of the cavity and to understand detailed physics involved in RF breakdown and multipacting, numerous instrumentation is installed on the cavity module and also in the experimental hall, which includes thermocouples, infrared sensors, electron pickups, fiber light guides, and radiation detectors. In this paper, we will present details of each diagnostic and initial test results.

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THPRI077

Electric Field Enhancement Study using an L-band Photocathode Gun

cathode, gun, experiment, simulation

3946

J.H. Shao, W. Gai
ANL, Argonne, Illinois, USA
H.B. Chen, J. Shi
TUB, Beijing, People's Republic of China
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
F.Y. Wang, L. Xiao
SLAC, Menlo Park, California, USA

RF breakdown in high gradient accelerating structures is a fundamental problem that is still needed better understanding. Past studies have indicated that field emission, which is usually represented by electric field enhancement (i.e. β) produced from the Fowler-Nordheim plot, is strongly coupled to the breakdown problem. A controlled surface study using a high gradient L-band RF gun is being carried out. With a flat cathode, the maximum electric field on the surface reached 10³ MV/m. And electric field as high as 565 MV/m on the surface was achieved by a pin-shaped cathode. The field enhancement factor was measured at different surface field during the conditioning process. Initial results of the study are presented in this paper.

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