IPAC2016 - List of Keywords (cryogenics)

Paper	Title	Other Keywords	Page
MOPMW010	Property Test of the Q-Factor for High Purity Copper at the Temperature of 20K	cavity, electron, linac, radiation	417
	A. Iino Sokendai, Ibaraki, Japan K. Endo TOYAMA Co., Ltd., Zama-shi, Kanagawa, Japan S. Yamaguchi KEK, Ibaraki, Japan
	A coherent parametric x-ray radiation (PXR) source based on a cryogenic electron linac has been developed by Toyama Co., Ltd, KEK and Nihon University. This accelerator is a C-band normal-conducting compact linac that requires a high Q factor in the accelerating and de-celerating structures. To obtain a high Q factor, the ac-celerating and decelerating structures are operated around 20 K, and are joined by diffusion bonding and are constructed with high-purity 6N8 copper which has very low resistivity in extremely low temperatures. In this study, we report the measurements and calculation of the residual resistance ratio (RRR) for 6N8 copper and oxy-gen-free copper (Class 1) as well as the Q factor for a pillbox cavity made of 6N8 copper and Class 1. The results of a low-power test of this accelerating structure at low temperature are reported. The Q factor for a 6N8 copper pillbox cavity is not much higher than that of a Class 1 pillbox cavity at low temperatures Moreover, the Q factor is saturated when RRR is greater than 500.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW010
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MOPMW038	Measurements of Copper RF Surface Resistance at Cryogenic Temperatures for Applications to X-Band and S-Band Accelerators	cavity, experiment, electron, coupling	487
	A.D. Cahill, A. Fukasawa, J.B. Rosenzweig UCLA, Los Angeles, California, USA G.B. Bowden, V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, P.B. Welander, C. Yoneda SLAC, Menlo Park, California, USA J. Guo JLab, Newport News, Virginia, USA Y. Higashi OIST, Onna-son, Okinawa, Japan
	Funding: Funding from DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515 Recent SLAC experiments with cryogenically cooled X-Band standing wave copper accelerating cavities have shown that these structures can operate with accelerating gradients of ~250 MV/m and low breakdown rates. These results prompted us to perform systematic studies of copper rf properties at cryogenic temperatures and low rf power. We placed copper cavities into a cryostat cooled by a pulse tube cryocooler, so cavities could be cooled to 4K. We used different shapes of cavities for the X-Band and S-Band measurements. Properties of the cavities were measured using a network analyzer. We calculated rf surface resistance from measured Q0 and Q external of the cavity at temperatures from 4 K to room temperature. The results were then compared to the theory proposed by Reuter and Sondheimer. These measurements are a part of studies with the goal of reaching very high operational accelerating gradients in normal conducting rf structures.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW038
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MOPMY032	Design and Upgrade the Safety System for the SRF Electronic System at the Taiwan Photon Source	SRF, vacuum, storage-ring, PLC	567
	F.-T. Chung, F.-Y. Chang, L.-H. Chang, M.H. Chang, L.J. Chen, M.-C. Lin, Z.K. Liu, C.H. Lo, C.L. Tsai, M.H. Tsai, Ch. Wang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	This paper presents some new designs and upgrades of a SRF interlock and electronic system. Based on the experience from Taiwan Light Source (TLS) that uses one Cornell-type superconducting cavity made by ACCEL in the storage-ring RF system [1], in the new TPS SRF system [3] home-made LLRF and SRF electronics [4] are constructed for two KEKB-type superconducting cavities [2] that are installed in the storage ring of circumference 518 m. For reliable operation of the TPS SRF system, enhanced safety functions of the system were added to improve the original SRF system in TLS. The improved functions can provide both the operators and the RF systems with a safer environment and clearer messages for trouble-shooting and malfunction status indications.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY032
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MOPOY055	Technologies for Stabilizing the Dynamic Vacuum and Charge Related Beam Loss in Heavy Ion Synchrotrons	ion, vacuum, heavy-ion, synchrotron	977
	P.J. Spiller, L.H.J. Bozyk, C. Omet, I. Pongrac, St. Wilfert GSI, Darmstadt, Germany
	With increasing the intensities of heavy ion beams in synchrotrons, charge related beam loss become more and more significant. In order to reduce space charge forces and to minimize the incoherent tune spread, the charge state of heavy Ions shall be lowered. Thus the cross section for charge related beam loss is further enhanced. For the FAIR project, GSI has developed a number of different technologies to stabilize the dynamic residual gas pressure and thereby to minimize charge related beam loss at high intensity heavy ion operation. Technologies suitable for such issues are, dedicated lattice structures, cold and warm ion catchers, NEG coated and cryogenic magnet chambers and cryo-adsorption pumps.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY055
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TUZB02	Challenge of In-vacuum and Cryogenic Undulator Technologies	undulator, vacuum, radiation, permanent-magnet	1080
	J.C. Huang, C.-H. Chang, C.H. Chang, T.Y. Chung, C.-S. Hwang, C.K. Yang, Y.T. Yu NSRRC, Hsinchu, Taiwan H. Kitamura RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	An in-vacuum undulator (IVU) opens the utilization of high-brilliance X-rays in the medium energy storage rings. The development of a short-period undulator with low phase error becomes important to bring X-ray into a new unprecedented brilliant light source in an ultimate storage ring (USR). NdFeB or PrFeB cryogenic permanent magnet undulators (CPMUs) with a short period have been developed worldwide to obtain high brilliance of undulator radiation. A CPMU has high resistance against beam-induced heat load and allow to operate at a narrow gap. In a low emittance or ultimate storage ring, not only the performance of an undulator but the choice of the lattice functions is very important to obtain high bril-liance of synchrotron radiation. The optimum betatron functions and zero dispersion function shall be given for a straight section at IVU/CPMUs. In this paper, the relevant factors and design issues for IVU/CPMU will be discussed. Many technological challenges of a short-period undulator associated with beam induced-heat load, phase errors, and the deformation of in-vacuum girders will also be presented herein.
	Slides TUZB02 [5.204 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUZB02
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TUPMB037	Instruments and Methods for the Magnetic Measurement of the Super-FRS Magnets	dipole, quadrupole, sextupole, octupole	1183
	G. Golluccio, M.C.L. Buzio, D. Caltabiano, G. Deferne, O. Dunkel, L. Fiscarelli, D. Giloteaux, C. Petrone, S. Russenschuck CERN, Geneva, Switzerland P. Schnizer GSI, Darmstadt, Germany
	The Super-FRS is a new fragment separator to be built as part of the Facility for Antiproton and Ion Research (FAIR) [\ref{fair_web}] at Darmstadt. The acceptance tests and magnetic measurements of the superferric separation dipoles and multiplets (containing quadrupole and higher-order magnets) will be performed at CERN in collaboration with GSI/FAIR [\ref{abstract_facility}]. This paper presents the methods and challenges of the magnetic field measurements, and the required instruments for measuring the transfer function, field quality, and magnetic axis. A prototype for each system has been produced in order to validate the measurement methods, the instruments, and the mechanical integration. In this paper will present the design and production of the prototypes, the design of the instruments for the series measurements, and the results of the metrological characterization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB037
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TUPMB040	LHC Accelerator Fault Tracker - First Experience	operation, hardware, ion, luminosity	1190
	A. Apollonio, L. Ponce, C. Roderick, R. Schmidt, B. Todd, D. Wollmann CERN, Geneva, Switzerland
	Availability is one of the key performance indicators of LHC operation, being directly correlated with integrated luminosity production. An effective tool for availability tracking is a necessity to ensure a coherent capture of fault information and relevant dependencies on operational modes and beam parameters. At the beginning of LHC Run 2 in 2015, the Accelerator Fault Tracking (AFT) tool was deployed at CERN to track faults or events affecting LHC operation. Information derived from the AFT is crucial for the identification of areas to improve LHC availability, and hence LHC physics production. For the 2015 run, the AFT has been used by members of the CERN Availability Working Group, LHC Machine coordinators and equipment owners to identify the main contributors to downtime and to understand the evolution of LHC availability throughout the year. In this paper the 2015 experience with the AFT for availability tracking is summarised and an overview of the first results as well as an outlook to future developments is given.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB040
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TUPMB046	The Preliminary Conceptual Design of a 2k Cryogneic System for Circular Electron Positron Collider (CEPC)	collider, booster, cryomodule, cavity	1199
	Y.P. Liu, L. Bian, R. Ge, R. Han, S.P. Li, M.J. Sang, L.R. Sun, M.F. Xu, R. Ye, J.Q. Zhang, J.H. Zhang, X.Z. Zhang, Z.Z. Zhang IHEP, Beijing, People's Republic of China
	The Circular Electron Positron Collider (CEPC) is a long-term collider project, which will serve as a Higgs Factory and offer a unique opportunity for direct searches for New Physics in the high-energy range far beyond LHC reach [1]. In the frame of this project, a large 2K cryogenic system will be built to provide coolant for superconducting cavities used in booster ring and collider ring. All the superconducting cavities will be working under 2K. This paper will give a brief introduction to the preliminary considerations of this large cryogenic system, including the general layout, heat load estimation, helium refrigerator, schematic flow diagram as well as the main parameters and working process
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB046
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TUPMB048	Compensation of Beam Induced Effects in LHC Cryogenic Systems	controls, electron, injection, simulation	1205
	B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González CERN, Geneva, Switzerland
	This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB048
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TUPMB049	Development of Separator Cooling System for Helium	experiment, radiation, controls, vacuum	1209
	W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB049
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TUPMB050	Development of Multi-channel Line for the NSRRC Cryogenic System	vacuum, radiation, photon, synchrotron	1212
	P.S.D. Chuang, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H.C. Li, W.R. Liao, T.F. Lin, H.H. Tsai NSRRC, Hsinchu, Taiwan
	For the past few years, the technology of X-ray photon source is getting more and more advanced, more and more countries are now striving to build the biggest synchrotron facility to meet its' need. In Taiwan, the construction of an electron accelerator with the energy of up to 3.5 GeV is constructed to fulfill the strong demands for an X-ray photon source with high brilliance and flux. Thus, to let the TPS be under stable operation, the cryogenic system is therefore very important. The refrigerant of the TPS Cryogenic System is Liquid Helium, to maintain liquid helium in its state, the temperature has to be maintained under 4.5K, however to let liquid helium turn into gas helium, only 20 W is needed. Therefore, the Multi-Channel Line is developed in our system to prevent heat from conduction in and letting liquid helium vaporize. Several mechanical parts have been designed to reduce heat loss and meet its needs, for example the Spacer. The paper presents a design methodology of long multi-channel helium cryogenic transfer lines. It describes some aspects thermo-mechanical calculation, supporting structure and contraction protection.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB050
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TUPMW017	Electron Cloud Observations during LHC Operation with 25 ns Beams	electron, operation, injection, simulation	1458
	K.S.B. Li, H. Bartosik, G. Iadarola, L. Mether, A. Romano, G. Rumolo, M. Schenk CERN, Geneva, Switzerland
	While during the Run 1 (2010-2012) of the Large Hadron Collider (LHC) most of the integrated luminosity was produced with 50 ns bunch spacing, for the Run 2 start-up (2015) it was decided to move to the nominal bunch spacing of 25 ns. As expected, with this beam configuration strong electron cloud effects were observed in the machine, which had to be mitigated with dedicated 'scrubbing' periods at injection energy. This enabled to start the operation with 25 ns beams at 6.5 TeV, but e-cloud effects continued to pose challenges while gradually increasing the number of circulating bunch trains. This contribution will review the encountered limitations and the mitigation measures that where put in place and will discuss possible strategies for further performance gain.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW017
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WEOCA01	Operation of the LHC with Protons at High Luminosity and High Energy	luminosity, operation, proton, emittance	2066
	G. Papotti, M. Albert, R. Alemany-Fernandez, G.E. Crockford, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, D. Jacquet, M. Lamont, D. Nisbet, L. Normann, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, M. Solfaroli Camillocci, R. Suykerbuyk, J.A. Uythoven, J. Wenninger CERN, Geneva, Switzerland
	In 2015 the Large Hadron Collider (LHC) entered the first year in its second long Run, after a 2-year shutdown that prepared it for high energy. The first two months of beam operation were dedicated to setting up the nominal cycle for proton-proton operation at 6.5 TeV/beam, and culminated with the first physics with 3 nominal bunches/ring at 13 TeV CoM on 3 June. The year continued with a stepwise intensity ramp up that allowed reaching 2244 bunches/ring for a peak luminosity of ~5·10³³ cm^-2s⁻¹ and a total of just above 4 fb-1 delivered to the high luminosity experiments. Beam operation was shaped by the high intensity effects, e.g. electron cloud and macroparticle-induced fast losses (UFOs), which on a few occasions caused the first beam induced quenches at high energy. This paper describes the operational experience with high intensity and high energy at the LHC, together with the issues that had to be tackled along the way.
	Slides WEOCA01 [4.013 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOCA01
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WEPMB024	Study on Nondestructive Inspections for Super-conducting Cavity	cavity, survey, interface, radiation	2174
	H. Tongu, H. Hokonohara, Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan R. Hajima, M. Sawamura JAEA, Ibaraki-ken, Japan H. Hayano, T. Kubo, T. Saeki, Y. Yamamoto KEK, Ibaraki, Japan
	Funding: The work is supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan. We have been studying nondestructive inspections for super-conducting spoke cavities. The temperature mapping (T-map) and X-ray mapping (X-map) are powerful inspection methods to locate a hot spot during the vertical RF tests. There would be a defect under the hot spot and the defect may be the cause of a quench. Our XT-map system (a combined system of T-map and X-map) has a high resolution in space. Because the huge amount of sensor signals are multiplexed at a hi-speed scanning rate in the vicinity of the sensors, the small number of signal lines makes the installation process easy and reduces the system complexity. Our XT-map got useful results on finding a defect in vertical RF tests of International Linear collider super-conducting cavity. The XT-map system is useful as low cost nondestructive inspections for superconducting spoke cavity. The study will be reported. progresses will be reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMB024
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WEPMR002	Ultimate Gradient Limitation in Niobium Superconducting Accelerating Cavities	simulation, factory, SRF, niobium	2254
	M. Checchin, A. Grassellino, M. Martinello, S. Posen, A. Romanenko Fermilab, Batavia, Illinois, USA M. Checchin, M. Martinello Illinois Institute of Technology, Chicago, Illlinois, USA J. Zasadzinski IIT, Chicago, Illinois, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The present study is addressed to the theoretical description of the ultimate gradient limitation in SRF cavities. Our intent is to exploit experimental data to confirm models which provide feed-backs on how to improve the current state-of-art. New theoretical insight on the cavities limiting factor can be suitable to improve the quench field of N-doped cavities, and therefore to take advantage of high Q0 at high gradients.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR002
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WEPMR005	Investigation of Thermal Acoustic Effects on SRF Cavities within CM1 at Fermilab	cavity, cryomodule, operation, acceleration	2265
	M.W. McGee, E.R. Harms, A.L. Klebaner, J.R. Leibfritz, A. Martinez, Y.M. Pischalnikov, W. Schappert Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy. Two TESLA-style 8-cavity cryomodules have been operated at Fermilab Accelerator Science and Technology (FAST), formerly the Superconducting Radio Frequency (SRF) Accelerator Test Facility. Operational instabilities were revealed during Radio Frequency (RF) power studies. These observations were complemented by the characterization of thermal acoustic effects on cavity microphonics manifested by apparent noisy boiling of helium involving vapor bubble and liquid vibration. The thermal acoustic measurements also consider pressure and temperature spikes which drive the phenomenon at low and high frequencies.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR005
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WEPMR018	Time Resolved Cryogenic Cooling Analysis of the Cornell Injector Cryomodule	HOM, cryomodule, simulation, operation	2298
	R.G. Eichhorn, A.C. Bartnik, B.M. Dunham, G.M. Ge, G.H. Hoffstaetter, H. Lee, M. Liepe, S.R. Markham, T.I. O'Connell, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	To demonstrate key parameters of a an energy recovery linac (ERL) at Cornel, an injector based on a photo gun and an SRF cryomodule was designed and built. The goal was to demonstrate high current generation while achieving low emittances. While the emittance goal has been reached, the current achieved so far is 75 mA. Even though this is a world record, it is still below the targeted 100 mA. While ramping up the current we observed excessive heating in the fundamental power coupler which we were able to track down to insufficient cooling of the 80 K intercepts. These intercepts are cooled by a stream of parallel cryogenic flows which we found to be unbalanced. In this paper we will review the finding, describe the analysis we did, modeling of the parallel flow and the modifications made to the module to overcome the heating.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR018
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WEPMR048	Hall Element Relative Position and Angle Calibrations for the Cryogenic Permanent Magnet Undulator	undulator, vacuum, permanent-magnet, dipole	2386
	L. Gong, W. Chen, W. Kang, L.Z. Li, H.H. Lu, Y.F. Yang IHEP, Beijing, People's Republic of China
	A three dimensions Hall probe will be manufactured for characterizing the magnetic performance of Cryogenic Permanent Magnet Undulator (CPMU) of Chinese High Energy Photon Source and the test facility (HEPS-TF) at Institute of High Energy Physics (IHEP). The positional and angular misalignment errors of the Hall sensors play an important role in the measurement accuracy of CPMU. In order to minimize the misalignment errors, a method of calibrating relative displacements and assembly angles of a 3-D Hall probe is carried out. In this paper, details of the calibration procedures and the data processing are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMR048
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WEPOR029	Concept of a Fire and Gas Safety System for Accelerators	interface, operation, radiation, detector	2729
	M. Dole, S. Grau, D. Raffourt CERN, Geneva, Switzerland
	Today CERN's facilities are equipped with automatic smoke and gas detection systems. Upon smoke or gas leak detection, local safety actions are automatically performed and alarms indicating the location and type of danger are transmitted to the CERN Fire Brigade. The firefighters then size their intervention based on the information received. The increasing complexity, size and quantity of CERN installations drives safety systems to evolve in the direction of simplicity. Intuitive interfaces are required to cope with high turnover of firefighters, and the inherent multinational environment. Global overview of alarms and safety actions statuses are needed by firefighters to decide on the best strategy for intervention. In some emergency situations, it might be necessary to manually trigger remote actions. CERN is studying a new concept, inspired by French standards, where the detection and protection layers are separated and act independently, but provide a common interface. This paper presents an application of this concept for the SPS* accelerator. Detection, fire-compartment and evacuation zones are presented, as well as the architecture of the detection and protection layers. *SPS: Super Proton Synchrotron
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR029
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THPMY007	Vacuum Performance of Amorphous Carbon Coating at Cryogenic Temperature with Presence of Proton Beams	electron, vacuum, experiment, simulation	3663
	R. Salemme, V. Baglin, G. Bregliozzi, P. Chiggiato CERN, Geneva, Switzerland
	Amorphous carbon (a-C) coating is the baseline electron multipacting mitigation strategy proposed for the Inner Triplets (IT) in the High Luminosity upgrade of the Large Hadron Collider (HL-LHC). As of 2014, the COLD bore EXperiment (COLDEX) is qualifying the performance of a-C coating at cryogenic temperature in a LHC type cryogenic vacuum system. In this paper, the experimental results following a cryogenic vacuum characterization of a-C coating in the 5 to 150 K temperature range are reviewed. We discuss the dynamic pressure rise, gas composition, dissipated heat load and electron activity observed within an accumulated beam time of 9 Ah. The results of dedicated experiments including pre-adsorption of different gas species (H2, CO) on the a-C coating are discussed. Based of phenomenological modeling, up-to-date secondary emission input parameters for a-C coatings are retrieved for electron cloud build-up simulations. Finally, first implications for the HL-LHC ITs design are drawn.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY007
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THPOR024	Electrical Power Budget for FCC-ee	collider, cavity, klystron, operation	3828
	F. Zimmermann, S. Aull, M. Benedikt, D. Bozzini, O. Brunner, J.-P. Burnet, A.C. Butterworth, R. Calaga, E. Jensen, V. Mertens, A. Milanese, M. Nonis, N. Schwerg, L.J. Tavian, J. Wenninger CERN, Geneva, Switzerland A.P. Blondel, M. Koratzinos DPNC, Genève, Switzerland Sh. Gorgi Zadeh Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany K. Oide KEK, Ibaraki, Japan L. Rinolfi JUAS, Archamps, France
	Funding: Supported by the European Commission under the Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453. We present a first rough estimate for the electrical power consumption of the FCC-ee lepton collider. This electrical power is dominated by the RF system, which provides the motivation for the ongoing R&D on highly efficient RF power sources. Other contributions come from the warm arc magnets, the cryogenics systems, cooling, ventilation, general services, the particle-physics detectors, and the injector complex.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR024
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THPOW041	Field Error Correction Considerations of Cryogenic Permanent Magnet Undulator (CPMU) for High Energy Photon Source Test Facility (HEPS-TF)*	undulator, simulation, operation, electron	4038
	Y.F. Yang, H.H. Lu, S.C. Sun, X.Z. Zhang IHEP, Beijing, People's Republic of China
	Considerations are made for field error corrections of a 2m-long CPMU in built for HEPS-TF. Field changes in cooling to liquid nitrogen temperature are simulated. 1st field integral of terminal changes by tens of Gauss cm and RMS of phase errors induced by cold contraction is less than 1° when temperature gradient along girder is below 1.5K/m. Field signature of magic finger is unchanged with temperature. Strategy of the field error correction is discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOW041
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Paper

Title

Other Keywords

Page

MOPMW010

Property Test of the Q-Factor for High Purity Copper at the Temperature of 20K

cavity, electron, linac, radiation

417

A. Iino
Sokendai, Ibaraki, Japan
K. Endo
TOYAMA Co., Ltd., Zama-shi, Kanagawa, Japan
S. Yamaguchi
KEK, Ibaraki, Japan

A coherent parametric x-ray radiation (PXR) source based on a cryogenic electron linac has been developed by Toyama Co., Ltd, KEK and Nihon University. This accelerator is a C-band normal-conducting compact linac that requires a high Q factor in the accelerating and de-celerating structures. To obtain a high Q factor, the ac-celerating and decelerating structures are operated around 20 K, and are joined by diffusion bonding and are constructed with high-purity 6N8 copper which has very low resistivity in extremely low temperatures. In this study, we report the measurements and calculation of the residual resistance ratio (RRR) for 6N8 copper and oxy-gen-free copper (Class 1) as well as the Q factor for a pillbox cavity made of 6N8 copper and Class 1. The results of a low-power test of this accelerating structure at low temperature are reported. The Q factor for a 6N8 copper pillbox cavity is not much higher than that of a Class 1 pillbox cavity at low temperatures Moreover, the Q factor is saturated when RRR is greater than 500.

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MOPMW038

Measurements of Copper RF Surface Resistance at Cryogenic Temperatures for Applications to X-Band and S-Band Accelerators

cavity, experiment, electron, coupling

487

A.D. Cahill, A. Fukasawa, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
G.B. Bowden, V.A. Dolgashev, M.A. Franzi, S.G. Tantawi, P.B. Welander, C. Yoneda
SLAC, Menlo Park, California, USA
J. Guo
JLab, Newport News, Virginia, USA
Y. Higashi
OIST, Onna-son, Okinawa, Japan

Funding: Funding from DOE SCGSR and DOE/SU Contract DE-AC02-76-SF00515
Recent SLAC experiments with cryogenically cooled X-Band standing wave copper accelerating cavities have shown that these structures can operate with accelerating gradients of ~250 MV/m and low breakdown rates. These results prompted us to perform systematic studies of copper rf properties at cryogenic temperatures and low rf power. We placed copper cavities into a cryostat cooled by a pulse tube cryocooler, so cavities could be cooled to 4K. We used different shapes of cavities for the X-Band and S-Band measurements. Properties of the cavities were measured using a network analyzer. We calculated rf surface resistance from measured Q0 and Q external of the cavity at temperatures from 4 K to room temperature. The results were then compared to the theory proposed by Reuter and Sondheimer. These measurements are a part of studies with the goal of reaching very high operational accelerating gradients in normal conducting rf structures.

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MOPMY032

Design and Upgrade the Safety System for the SRF Electronic System at the Taiwan Photon Source

SRF, vacuum, storage-ring, PLC

567

F.-T. Chung, F.-Y. Chang, L.-H. Chang, M.H. Chang, L.J. Chen, M.-C. Lin, Z.K. Liu, C.H. Lo, C.L. Tsai, M.H. Tsai, Ch. Wang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

This paper presents some new designs and upgrades of a SRF interlock and electronic system. Based on the experience from Taiwan Light Source (TLS) that uses one Cornell-type superconducting cavity made by ACCEL in the storage-ring RF system [1], in the new TPS SRF system [3] home-made LLRF and SRF electronics [4] are constructed for two KEKB-type superconducting cavities [2] that are installed in the storage ring of circumference 518 m. For reliable operation of the TPS SRF system, enhanced safety functions of the system were added to improve the original SRF system in TLS. The improved functions can provide both the operators and the RF systems with a safer environment and clearer messages for trouble-shooting and malfunction status indications.

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MOPOY055

Technologies for Stabilizing the Dynamic Vacuum and Charge Related Beam Loss in Heavy Ion Synchrotrons

ion, vacuum, heavy-ion, synchrotron

977

P.J. Spiller, L.H.J. Bozyk, C. Omet, I. Pongrac, St. Wilfert
GSI, Darmstadt, Germany

With increasing the intensities of heavy ion beams in synchrotrons, charge related beam loss become more and more significant. In order to reduce space charge forces and to minimize the incoherent tune spread, the charge state of heavy Ions shall be lowered. Thus the cross section for charge related beam loss is further enhanced. For the FAIR project, GSI has developed a number of different technologies to stabilize the dynamic residual gas pressure and thereby to minimize charge related beam loss at high intensity heavy ion operation. Technologies suitable for such issues are, dedicated lattice structures, cold and warm ion catchers, NEG coated and cryogenic magnet chambers and cryo-adsorption pumps.

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TUZB02

Challenge of In-vacuum and Cryogenic Undulator Technologies

undulator, vacuum, radiation, permanent-magnet

1080

J.C. Huang, C.-H. Chang, C.H. Chang, T.Y. Chung, C.-S. Hwang, C.K. Yang, Y.T. Yu
NSRRC, Hsinchu, Taiwan
H. Kitamura
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

An in-vacuum undulator (IVU) opens the utilization of high-brilliance X-rays in the medium energy storage rings. The development of a short-period undulator with low phase error becomes important to bring X-ray into a new unprecedented brilliant light source in an ultimate storage ring (USR). NdFeB or PrFeB cryogenic permanent magnet undulators (CPMUs) with a short period have been developed worldwide to obtain high brilliance of undulator radiation. A CPMU has high resistance against beam-induced heat load and allow to operate at a narrow gap. In a low emittance or ultimate storage ring, not only the performance of an undulator but the choice of the lattice functions is very important to obtain high bril-liance of synchrotron radiation. The optimum betatron functions and zero dispersion function shall be given for a straight section at IVU/CPMUs. In this paper, the relevant factors and design issues for IVU/CPMU will be discussed. Many technological challenges of a short-period undulator associated with beam induced-heat load, phase errors, and the deformation of in-vacuum girders will also be presented herein.

Slides TUZB02 [5.204 MB]

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TUPMB037

Instruments and Methods for the Magnetic Measurement of the Super-FRS Magnets

dipole, quadrupole, sextupole, octupole

1183

G. Golluccio, M.C.L. Buzio, D. Caltabiano, G. Deferne, O. Dunkel, L. Fiscarelli, D. Giloteaux, C. Petrone, S. Russenschuck
CERN, Geneva, Switzerland
P. Schnizer
GSI, Darmstadt, Germany

The Super-FRS is a new fragment separator to be built as part of the Facility for Antiproton and Ion Research (FAIR) [\ref{fair_web}] at Darmstadt. The acceptance tests and magnetic measurements of the superferric separation dipoles and multiplets (containing quadrupole and higher-order magnets) will be performed at CERN in collaboration with GSI/FAIR [\ref{abstract_facility}]. This paper presents the methods and challenges of the magnetic field measurements, and the required instruments for measuring the transfer function, field quality, and magnetic axis. A prototype for each system has been produced in order to validate the measurement methods, the instruments, and the mechanical integration. In this paper will present the design and production of the prototypes, the design of the instruments for the series measurements, and the results of the metrological characterization.

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TUPMB040

LHC Accelerator Fault Tracker - First Experience

operation, hardware, ion, luminosity

1190

A. Apollonio, L. Ponce, C. Roderick, R. Schmidt, B. Todd, D. Wollmann
CERN, Geneva, Switzerland

Availability is one of the key performance indicators of LHC operation, being directly correlated with integrated luminosity production. An effective tool for availability tracking is a necessity to ensure a coherent capture of fault information and relevant dependencies on operational modes and beam parameters. At the beginning of LHC Run 2 in 2015, the Accelerator Fault Tracking (AFT) tool was deployed at CERN to track faults or events affecting LHC operation. Information derived from the AFT is crucial for the identification of areas to improve LHC availability, and hence LHC physics production. For the 2015 run, the AFT has been used by members of the CERN Availability Working Group, LHC Machine coordinators and equipment owners to identify the main contributors to downtime and to understand the evolution of LHC availability throughout the year. In this paper the 2015 experience with the AFT for availability tracking is summarised and an overview of the first results as well as an outlook to future developments is given.

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TUPMB046

The Preliminary Conceptual Design of a 2k Cryogneic System for Circular Electron Positron Collider (CEPC)

collider, booster, cryomodule, cavity

1199

Y.P. Liu, L. Bian, R. Ge, R. Han, S.P. Li, M.J. Sang, L.R. Sun, M.F. Xu, R. Ye, J.Q. Zhang, J.H. Zhang, X.Z. Zhang, Z.Z. Zhang
IHEP, Beijing, People's Republic of China

The Circular Electron Positron Collider (CEPC) is a long-term collider project, which will serve as a Higgs Factory and offer a unique opportunity for direct searches for New Physics in the high-energy range far beyond LHC reach [1]. In the frame of this project, a large 2K cryogenic system will be built to provide coolant for superconducting cavities used in booster ring and collider ring. All the superconducting cavities will be working under 2K. This paper will give a brief introduction to the preliminary considerations of this large cryogenic system, including the general layout, heat load estimation, helium refrigerator, schematic flow diagram as well as the main parameters and working process

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TUPMB048

Compensation of Beam Induced Effects in LHC Cryogenic Systems

controls, electron, injection, simulation

1205

B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González
CERN, Geneva, Switzerland

This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.

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TUPMB049

Development of Separator Cooling System for Helium

experiment, radiation, controls, vacuum

1209

W.R. Liao, S.-H. Chang, W.-S. Chiou, P.S.D. Chuang, F. Z. Hsiao, H.C. Li, T.F. Lin, H.H. Tsai
NSRRC, Hsinchu, Taiwan

A helium phase separator with a condenser is under fabrication and assembled at National Synchrotron Radiation Research Centre (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryocooler of Gifford-McMahon type. We developed a 100 litre (ltr) helium phase separator with a small heat loss as a prototype. The experimental results for the total cooling capacity of the phase separator are 0.73 W at 1.67 bara, which includes the effect of thermal conduction and thermal radiation from the environment. The helium liquefaction rate is 2 ltr/day with a 100 ltr vessel. The mechanism of heat transfer in phase separator was investigated and discussed. This paper presents the experiment of helium liquefaction process of 100 ltr separator with condenser, which was a key component of the helium phase separator.

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TUPMB050

Development of Multi-channel Line for the NSRRC Cryogenic System

vacuum, radiation, photon, synchrotron

1212

P.S.D. Chuang, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, H.C. Li, W.R. Liao, T.F. Lin, H.H. Tsai
NSRRC, Hsinchu, Taiwan

For the past few years, the technology of X-ray photon source is getting more and more advanced, more and more countries are now striving to build the biggest synchrotron facility to meet its' need. In Taiwan, the construction of an electron accelerator with the energy of up to 3.5 GeV is constructed to fulfill the strong demands for an X-ray photon source with high brilliance and flux. Thus, to let the TPS be under stable operation, the cryogenic system is therefore very important. The refrigerant of the TPS Cryogenic System is Liquid Helium, to maintain liquid helium in its state, the temperature has to be maintained under 4.5K, however to let liquid helium turn into gas helium, only 20 W is needed. Therefore, the Multi-Channel Line is developed in our system to prevent heat from conduction in and letting liquid helium vaporize. Several mechanical parts have been designed to reduce heat loss and meet its needs, for example the Spacer. The paper presents a design methodology of long multi-channel helium cryogenic transfer lines. It describes some aspects thermo-mechanical calculation, supporting structure and contraction protection.

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TUPMW017

Electron Cloud Observations during LHC Operation with 25 ns Beams

electron, operation, injection, simulation

1458

K.S.B. Li, H. Bartosik, G. Iadarola, L. Mether, A. Romano, G. Rumolo, M. Schenk
CERN, Geneva, Switzerland

While during the Run 1 (2010-2012) of the Large Hadron Collider (LHC) most of the integrated luminosity was produced with 50 ns bunch spacing, for the Run 2 start-up (2015) it was decided to move to the nominal bunch spacing of 25 ns. As expected, with this beam configuration strong electron cloud effects were observed in the machine, which had to be mitigated with dedicated 'scrubbing' periods at injection energy. This enabled to start the operation with 25 ns beams at 6.5 TeV, but e-cloud effects continued to pose challenges while gradually increasing the number of circulating bunch trains. This contribution will review the encountered limitations and the mitigation measures that where put in place and will discuss possible strategies for further performance gain.

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WEOCA01

Operation of the LHC with Protons at High Luminosity and High Energy

luminosity, operation, proton, emittance

2066

G. Papotti, M. Albert, R. Alemany-Fernandez, G.E. Crockford, K. Fuchsberger, R. Giachino, M. Giovannozzi, G.H. Hemelsoet, W. Höfle, D. Jacquet, M. Lamont, D. Nisbet, L. Normann, M. Pojer, L. Ponce, S. Redaelli, B. Salvachua, M. Solfaroli Camillocci, R. Suykerbuyk, J.A. Uythoven, J. Wenninger
CERN, Geneva, Switzerland

In 2015 the Large Hadron Collider (LHC) entered the first year in its second long Run, after a 2-year shutdown that prepared it for high energy. The first two months of beam operation were dedicated to setting up the nominal cycle for proton-proton operation at 6.5 TeV/beam, and culminated with the first physics with 3 nominal bunches/ring at 13 TeV CoM on 3 June. The year continued with a stepwise intensity ramp up that allowed reaching 2244 bunches/ring for a peak luminosity of ~5·10³³ cm^-2s⁻¹ and a total of just above 4 fb-1 delivered to the high luminosity experiments. Beam operation was shaped by the high intensity effects, e.g. electron cloud and macroparticle-induced fast losses (UFOs), which on a few occasions caused the first beam induced quenches at high energy. This paper describes the operational experience with high intensity and high energy at the LHC, together with the issues that had to be tackled along the way.

Slides WEOCA01 [4.013 MB]

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WEPMB024

Study on Nondestructive Inspections for Super-conducting Cavity

cavity, survey, interface, radiation

2174

H. Tongu, H. Hokonohara, Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
R. Hajima, M. Sawamura
JAEA, Ibaraki-ken, Japan
H. Hayano, T. Kubo, T. Saeki, Y. Yamamoto
KEK, Ibaraki, Japan

Funding: The work is supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
We have been studying nondestructive inspections for super-conducting spoke cavities. The temperature mapping (T-map) and X-ray mapping (X-map) are powerful inspection methods to locate a hot spot during the vertical RF tests. There would be a defect under the hot spot and the defect may be the cause of a quench. Our XT-map system (a combined system of T-map and X-map) has a high resolution in space. Because the huge amount of sensor signals are multiplexed at a hi-speed scanning rate in the vicinity of the sensors, the small number of signal lines makes the installation process easy and reduces the system complexity. Our XT-map got useful results on finding a defect in vertical RF tests of International Linear collider super-conducting cavity. The XT-map system is useful as low cost nondestructive inspections for superconducting spoke cavity. The study will be reported. progresses will be reported.

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WEPMR002

Ultimate Gradient Limitation in Niobium Superconducting Accelerating Cavities

simulation, factory, SRF, niobium

2254

M. Checchin, A. Grassellino, M. Martinello, S. Posen, A. Romanenko
Fermilab, Batavia, Illinois, USA
M. Checchin, M. Martinello
Illinois Institute of Technology, Chicago, Illlinois, USA
J. Zasadzinski
IIT, Chicago, Illinois, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The present study is addressed to the theoretical description of the ultimate gradient limitation in SRF cavities. Our intent is to exploit experimental data to confirm models which provide feed-backs on how to improve the current state-of-art. New theoretical insight on the cavities limiting factor can be suitable to improve the quench field of N-doped cavities, and therefore to take advantage of high Q0 at high gradients.

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WEPMR005

Investigation of Thermal Acoustic Effects on SRF Cavities within CM1 at Fermilab

cavity, cryomodule, operation, acceleration

2265

M.W. McGee, E.R. Harms, A.L. Klebaner, J.R. Leibfritz, A. Martinez, Y.M. Pischalnikov, W. Schappert
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.
Two TESLA-style 8-cavity cryomodules have been operated at Fermilab Accelerator Science and Technology (FAST), formerly the Superconducting Radio Frequency (SRF) Accelerator Test Facility. Operational instabilities were revealed during Radio Frequency (RF) power studies. These observations were complemented by the characterization of thermal acoustic effects on cavity microphonics manifested by apparent noisy boiling of helium involving vapor bubble and liquid vibration. The thermal acoustic measurements also consider pressure and temperature spikes which drive the phenomenon at low and high frequencies.

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WEPMR018

Time Resolved Cryogenic Cooling Analysis of the Cornell Injector Cryomodule

HOM, cryomodule, simulation, operation

2298

R.G. Eichhorn, A.C. Bartnik, B.M. Dunham, G.M. Ge, G.H. Hoffstaetter, H. Lee, M. Liepe, S.R. Markham, T.I. O'Connell, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

To demonstrate key parameters of a an energy recovery linac (ERL) at Cornel, an injector based on a photo gun and an SRF cryomodule was designed and built. The goal was to demonstrate high current generation while achieving low emittances. While the emittance goal has been reached, the current achieved so far is 75 mA. Even though this is a world record, it is still below the targeted 100 mA. While ramping up the current we observed excessive heating in the fundamental power coupler which we were able to track down to insufficient cooling of the 80 K intercepts. These intercepts are cooled by a stream of parallel cryogenic flows which we found to be unbalanced. In this paper we will review the finding, describe the analysis we did, modeling of the parallel flow and the modifications made to the module to overcome the heating.

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WEPMR048

Hall Element Relative Position and Angle Calibrations for the Cryogenic Permanent Magnet Undulator

undulator, vacuum, permanent-magnet, dipole

2386

L. Gong, W. Chen, W. Kang, L.Z. Li, H.H. Lu, Y.F. Yang
IHEP, Beijing, People's Republic of China

A three dimensions Hall probe will be manufactured for characterizing the magnetic performance of Cryogenic Permanent Magnet Undulator (CPMU) of Chinese High Energy Photon Source and the test facility (HEPS-TF) at Institute of High Energy Physics (IHEP). The positional and angular misalignment errors of the Hall sensors play an important role in the measurement accuracy of CPMU. In order to minimize the misalignment errors, a method of calibrating relative displacements and assembly angles of a 3-D Hall probe is carried out. In this paper, details of the calibration procedures and the data processing are presented.

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WEPOR029

Concept of a Fire and Gas Safety System for Accelerators

interface, operation, radiation, detector

2729

M. Dole, S. Grau, D. Raffourt
CERN, Geneva, Switzerland

Today CERN's facilities are equipped with automatic smoke and gas detection systems. Upon smoke or gas leak detection, local safety actions are automatically performed and alarms indicating the location and type of danger are transmitted to the CERN Fire Brigade. The firefighters then size their intervention based on the information received. The increasing complexity, size and quantity of CERN installations drives safety systems to evolve in the direction of simplicity. Intuitive interfaces are required to cope with high turnover of firefighters, and the inherent multinational environment. Global overview of alarms and safety actions statuses are needed by firefighters to decide on the best strategy for intervention. In some emergency situations, it might be necessary to manually trigger remote actions. CERN is studying a new concept, inspired by French standards, where the detection and protection layers are separated and act independently, but provide a common interface. This paper presents an application of this concept for the SPS* accelerator. Detection, fire-compartment and evacuation zones are presented, as well as the architecture of the detection and protection layers.
*SPS: Super Proton Synchrotron

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THPMY007

Vacuum Performance of Amorphous Carbon Coating at Cryogenic Temperature with Presence of Proton Beams

electron, vacuum, experiment, simulation

3663

R. Salemme, V. Baglin, G. Bregliozzi, P. Chiggiato
CERN, Geneva, Switzerland

Amorphous carbon (a-C) coating is the baseline electron multipacting mitigation strategy proposed for the Inner Triplets (IT) in the High Luminosity upgrade of the Large Hadron Collider (HL-LHC). As of 2014, the COLD bore EXperiment (COLDEX) is qualifying the performance of a-C coating at cryogenic temperature in a LHC type cryogenic vacuum system. In this paper, the experimental results following a cryogenic vacuum characterization of a-C coating in the 5 to 150 K temperature range are reviewed. We discuss the dynamic pressure rise, gas composition, dissipated heat load and electron activity observed within an accumulated beam time of 9 Ah. The results of dedicated experiments including pre-adsorption of different gas species (H2, CO) on the a-C coating are discussed. Based of phenomenological modeling, up-to-date secondary emission input parameters for a-C coatings are retrieved for electron cloud build-up simulations. Finally, first implications for the HL-LHC ITs design are drawn.

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THPOR024

Electrical Power Budget for FCC-ee

collider, cavity, klystron, operation

3828

F. Zimmermann, S. Aull, M. Benedikt, D. Bozzini, O. Brunner, J.-P. Burnet, A.C. Butterworth, R. Calaga, E. Jensen, V. Mertens, A. Milanese, M. Nonis, N. Schwerg, L.J. Tavian, J. Wenninger
CERN, Geneva, Switzerland
A.P. Blondel, M. Koratzinos
DPNC, Genève, Switzerland
Sh. Gorgi Zadeh
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
K. Oide
KEK, Ibaraki, Japan
L. Rinolfi
JUAS, Archamps, France

Funding: Supported by the European Commission under the Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453.
We present a first rough estimate for the electrical power consumption of the FCC-ee lepton collider. This electrical power is dominated by the RF system, which provides the motivation for the ongoing R&D on highly efficient RF power sources. Other contributions come from the warm arc magnets, the cryogenics systems, cooling, ventilation, general services, the particle-physics detectors, and the injector complex.

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THPOW041

Field Error Correction Considerations of Cryogenic Permanent Magnet Undulator (CPMU) for High Energy Photon Source Test Facility (HEPS-TF)*

undulator, simulation, operation, electron

4038

Y.F. Yang, H.H. Lu, S.C. Sun, X.Z. Zhang
IHEP, Beijing, People's Republic of China

Considerations are made for field error corrections of a 2m-long CPMU in built for HEPS-TF. Field changes in cooling to liquid nitrogen temperature are simulated. 1st field integral of terminal changes by tens of Gauss cm and RMS of phase errors induced by cold contraction is less than 1° when temperature gradient along girder is below 1.5K/m. Field signature of magic finger is unchanged with temperature. Strategy of the field error correction is discussed.

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