THPPD —  Poster Session   (24-May-12   16:00—18:00)

Paper	Title	Page
THPPD001	Stretched-wire Measurements of Small Bore Multipole Magnets	3500
	G. Lebec, J. Chavanne, C. Penel ESRF, Grenoble, France
	Stretched-wire (SW) measurements of magnetic multipoles have been performed at radii ranging from 0.5 mm to 4 mm, with an accuracy of 10-3 of the main multipole component. Theoretical aspects of SW measurements were investigated. The processing of the measured signals is based on a least square approach, instead of the Fourier transform widely used for rotating coil measurements. It allows correcting numerically the position errors of the SW and designing SW trajectory which are not sensitive to the main multipole, as with “bucked” rotating coils. This SW measurement bench was developed for the characterization of new ESRF magnets. It has been tested first with large aperture multipole magnets. An accuracy of 10-4 has been obtained for a measurement radius of 30 mm. There is a demand in the magnetic measurement community for measuring small bore multipole magnets, with radius smaller than 5 mm. A small permanent magnet quadrupole was built in order to test the bench at small measurement radii.
THPPD002	The First Magnetic Field Control (B-Train) to Optimize the Duty Cycle of a Synchrotron in Clinical Operation	3503
	E. Feldmeier, R. Cee, M. Galonska, Th. Haberer, A. Peters, S. Scheloske HIT, Heidelberg, Germany
	In December 2011 the Heidelberg Ion Therapy Center started to use the magnetic field feedback control for its clinical operation. Therewith the magnetic field deviation of the ramped magnets in the synchrotron depending on eddy currents and hysteresis are no longer in effect. Waiting times on the flattop and the "chimney" in the recovery phase of the synchrotron cycle are no longer necessary. The efficiency of the accelerator is increased by more than 20\% and the treatment time shortens accordingly. The core of the magnetic feedback system is a real time measuring system of the magnetic field with extremely high precision.
THPPD007	ILSF Storage Ring Magnets	3506
	S. Fatehi, R. Aslani, M.R. Khabbazi IPM, Tehran, Iran
	Iranian Light Source Facility (ILSF) is a 3 GeV storage ring consisting 32 combined bending magnets in 2 types, 104 quadrupoles in 9 families and 128 sextupoles in 9 families. It was decided to use curved C-type, parallel ends, combined bending magnets that have the same lengths, a central fields of 1.42 T and total gap of 32 mm but quadrupole components of g1=-3.837 and g2=-5.839 T/m. Using two dimensional code POISSON and FEMM and applying appropriate shims, pole profile was optimized to maintain the field homogeneity over the full horizontal aperture of ±10, such that, field tolerance is of the order of 10-4. Also a pole and yoke geometry was developed for the quadrupole, with a field gradient of 23 T/m, bore radius of 30.5 mm and magnetic length of 0.53m which is the maximum possible values in the lattice. Obtained field tolerance is of the order of 10-4 in the good field region 18 mm. Sextupoles are supposed to have a bore radius of 34 mm, max sextupole component of 700 T/m2 and are designed in order to achieve a field tolerance of 10-3 in the good field region of 12 mm. Also in order to investigate the end effects 3D calculations has been done by using Radia 3D code.
THPPD008	Status of the PAL-XFEL Undulator System	3509
	D.E. Kim, H.S. Han, Y.-G. Jung, H.-G. Lee, W.W. Lee, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea J. Pflüger European XFEL GmbH, Hamburg, Germany
	Funding: Work supported by POSCO and MEST of Korea. Pohang Accelerator Laboratory (PAL) is developing 10 GeV, 0.1 nm SASE based FEL for high power, short pulse X-ray coherent photon sources named PAL-XFEL. At the first stage PAL-XFEL needs two undulator lines for photon source. PAL is developing undulator magnetic structure based on EU-XFEL design. The hard Xray undulator features 7.2 mm min magnetic gap, and 5.0 m magnetic length with maximum effective magnetic field larger than 0.908 T to achieve 0.1nm radiation at 10 GeV electron energy. In this report, we discuss the status of the hard X-ray undulator and soft X-ray undulator designs.
THPPD009	Accelerator Magnets R&D Programme at CERN	3512
	D. Tommasini, L. Bottura, G. De Rijk, L. Rossi CERN, Geneva, Switzerland
	The exploitation and evolution of the CERN accelerator complex pose a continuous challenge for magnet engineers. Superconducting and resistive magnets have a comparable share. The overall mass of either is approximately 50,000 tons, spread over 3 major machines (PS, SPS and LHC), two large experimental area, and a number of smaller experiments and accelerator rings. On the short term (2012-2014) the CERN plan is to upgrade its injection chain (Linac4) and experimental area (HIE-Isolde, ELENA) that require mostly a multitude of resistive magnets. The medium-term plan for the evolution of the LHC complex (2015-2021), also referred to as High-Luminosity LHC, foresees interventions on about 1 km of the machine, with magnets to be substituted with higher field, larger aperture, or both. On the long term (2025-2035) we are exploring the technological challenges of very high field magnets, at the verge of 20 T for a High Energy LHC (HE-LHC), or extremely stable high gradient quadrupoles for the Compact Linear Collider (CLIC). In this paper we provide an overview of the R&D activities addressing the various lines of development, the technology milestones, and a broad time schedule.
THPPD010	Design, Assembly and First Measurements of a Short Model for CLIC Final Focus Hybrid Quadrupole QD0	3515
	M. Modena, O. Dunkel, J.G. Perez, C. Petrone, P.A. Thonet, D. Tommasini CERN, Geneva, Switzerland E. Solodko, A.S. Vorozhtsov JINR, Dubna, Moscow Region, Russia
	In the framework of the Compact Linear Collider (CLIC) R&D, a tunable hybrid magnet design has been proposed for the final focus QD0 quadrupole. A short model of the magnet has been realized in order to validate the novel design and its expected performances. In order to achieve extremely high quadrupole gradients (>500 T/m), the magnet design combines: a core structure made in magnetic CoFe alloy “Permendur”, permanent magnet blocks, and air-cooled electromagnetic coils. Relevant aspects of this design are the wide tunability of the gradient range, the compactness and the absence of any vibrations. In this paper a reminder of the magnet design concept is given; then, the procurement and assembly main aspects are presented, followed by the results of the magnetic measurements. Finally, some manufacturing considerations relative to a full size magnet procurement are discussed.
THPPD011	Radiation Hard Magnets at the Paul Scherrer Institute	3518
	A.L. Gabard, J.P. Duppich, D. George Paul Scherrer Institut, Villigen, Switzerland
	Radiation hard magnets have been in operation at PSI for more than 30 years. Throughout this period, extensive experience was gained regarding both the conceptual design of these magnets and their operation. Worldwide, upcoming future projects for high intensity accelerators and spallation sources will create an increasing need for radiation hard magnets. Through a presentation of the PSI main accelerator facilities, this paper describes the lessons learned over the years regarding the operation of radiation hard magnets and explains a few basic design concepts adopted by PSI based on this experience.
THPPD012	Measurement of Injection System of AC Septum Magnets for TPS Storage Ring	3521
	F.-Y. Lin, C.-H. Chang, C.-S. Fann, C.-S. Hwang, C.S. Yang NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a 3 GeV third generation light source and will be operated in top-up injection mode. The leakage field of the septum magnet will dominate the injection performance. The septum magnets, parts of injection system, consist of AC and DC current mode magnets. The AC septum magnet were designed and constructed by NSRRC. In order to verify the magnetic field quality and the leakage field distribution, the search coil probe and the printed circuit technology for long coil probe measurement systems are developed and implemented for magnetic field measurement. This paper will describe the magnetic field measurement system, the magnetic field mapping results and the field shielding performance of AC septum magnet.
THPPD014	Design and Performance of Various kinds of Corrector Magnets for the Taiwan Photon Source	3524
	C.Y. Kuo, C.-H. Chang, M.-H. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin NSRRC, Hsinchu, Taiwan
	Three types of DC corrector magnets will be installed in the booster ring (BR), LINAC to booster (LTB) and booster to storage ring (BTS) in the Taiwan photon source (TPS). These DC corrector magnets have different gap sizes, iron lengths and field strengths for different bending angles to optimize the electron beam. The DC magnetic fields are simulated by TOSCA 2D/3D static field analysis and optimum processes are discussed. An AC steering fast feedback corrector (FFC) combines horizontal and vertical dipole fields for the fast feedback correction in the storage ring (SR). The field variation with the alternating current in the 300Hz frequency of the FFC magnet is simulated by the Opera 3d ELEKTRA/SS analysis module to estimate the operating current. This paper will be presented about features, design concept and results of field measurement of these corrector magnets. NSRRC, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
THPPD015	Character and Performance of Magnets for the TPS Storage Ring	3527
	J.C. Jan, C.-H. Chang, H.-H. Chen, Y.L. Chu, C.-S. Hwang, C.Y. Kuo, F.-Y. Lin, C.S. Yang, Y.T. Yu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is a third-generation light source. The orbit of the electron beam will be controlled with 48 dipoles, 240 quadrupoles, 168 sextupoles and several correctors in the storage ring. The construction of the first magnets for one sector, including prototype magnets, is to be completed during 2011 December. The mechanical dimensions of these magnets have been examined on a precise 3D-coordinate-measuring machine (CMM). The field strength, effective length and multipole errors were inspected with a rotating-coil measurement system (RCS) and a Hall-probe measurement system (HPS). The field center of the quadrupole and sextupole magnets is shimmed with a precise shimming block on the RCS bench. The inaccuracy of the position of the field center will be within 0.01 mm after shimming the feet. This work reports the current status, the construction performance, the mechanical shimming algorithm and the relative construction issue of the high precision magnet.
THPPD016	Construction and Measurement of Novel Adjustable Permanent Magnet Quadrupoles for CLIC	3530
	B.J.A. Shepherd, J.A. Clarke STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom N.A. Collomb STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
	The CLIC drive beam decelerator requires 41,848 quadrupoles along its 42km length. In response to concerns over the heat load and operating costs of electromagnet systems, ASTeC in collaboration with CERN is developing adjustable permanent magnet-based quadrupoles. This novel design concept uses moving permanent magnets to adjust the quadrupole strength over a wide operating range. The design has focused not just on achieving the field strength and quality required but has also tried to make the design well suited to mass production, as the CLIC project requires 50 magnets to be completed every day for three years. Two permanent magnet quadrupole families have been designed, for the low and high energy ends of the decelerator respectively. We present the current status of the project, including construction and magnetic measurements of the first prototype.
THPPD017	Mu2e AC Dipole 300 kHz and 5.1 MHz Tests and Comparison of Nickel-Zinc Ferrites	3533
	L. Elementi, K.R. Bourkland, D.J. Harding, V.S. Kashikhin, A.V. Makarov, H. Pfeffer, G. Velev Fermilab, Batavia, USA
	To suppress any background events coming from the inter-bunch proton interactions during the muon transport and decay window for the Mu2e experiment, a beam extinction scheme based on two dipoles running at ~300 kHz and 5.1 MHz is considered. The effective field of these magnets is synchronized to the proton bunch spacing in such a way that the bunches are transported at the sinus nodes. Two types Ni-Zn ferrites are considered for these dipoles. Ferrites, their characteristics and ferrites selection is herein discussed through measurements performed under conditions close to operational. The excitation system and the measurement of some characteristics of the magnetic field and field shape and measurement mechanism are also presented.
THPPD018	Precision Magnet Measurements for X-band Accelerator Quadrupole Triplets	3536
	R.A. Marsh, S.G. Anderson, J.P. Armstrong LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. Beamline magnets will include an emittance compensation solenoid, windowpane steering dipoles, and quadrupole magnets. Demanding tolerances have been placed on the alignment of these magnets, which directly affects the electron bunch beam quality. A magnet mapping system has been established at LLNL in order to ensure the delivered magnets match their field specification, and the mountings are aligned and capable of reaching the specified alignment tolerances. The magnet measurement system will be described which uses a 3-axis Lakeshore gauss probe mounted on a 3-axis translation stage. Alignment accuracy and precision will be discussed, as well as centering measurements and analysis. The dependence on data analysis over direct multi-pole measurement allows a significant improvement in useful alignment information. Detailed analysis of measurements on the beamline quadrupoles will be discussed, including multi-pole content both from alignment of the magnets, and the intrinsic level of multi-pole magnetic field.
THPPD019	Accurately Determining the Parameters of a Magnet Coil by 3D CAD Design	3539
	N. Li LBNL, Berkeley, California, USA C. Chen, H.J. Hu, J. Jin, W.Y. Wen, L. Yin SINAP, Shanghai, People's Republic of China
	Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231. Traditionally, the average turn length and number of turns of a conventional magnet coil is roughly estimated during the magnet physical design. Based on these estimates, the resistance, water flow and overall dimensions of the coil are calculated. But for a complex coil shape, it is very difficult to determine how many turns a coil will have and, more importantly, specifically how it will be wound. In many cases, an engineer will use a scale model to do a winding trial, but the coil parameters, such as the conductor length and overall coil dimensions, still cannot be precisely determined. 3D CAD modeling was used for the design of the Advanced Light Source (ALS) combined function sextupole magnet coils. The winding procedures for 11 types of coils were all determined by the models. The resistances and water flow requirements of those coils were calculated from the 3D models, and those parameters were used as criteria for production quality control thereafter. This paper will introduce some basic modeling techniques that are useful for 3D CAD modeling of magnet coils. The coil data comparison between 3D model and true built coils will be introduced as well.
THPPD020	Test of a 1.8 Tesla, 400 Hz Dipole for a Muon Synchrotron	3542
	D.J. Summers, L.M. Cremaldi, T.L. Hart, L.P. Perera, M. Reep UMiss, University, Mississippi, USA S.U. Hansen, M.L. Lopes Fermilab, Batavia, USA J. Reidy Oxford High School, Mississippi, USA H. Witte BNL, Upton, Long Island, New York, USA
	Funding: Supported by DE-FG05-91ER40622. A 1.8 Tesla dipole magnet using 0.011" AK Steel TRAN-COR H-1 grain oriented silicon steel laminations has been constructed as a prototype for a muon synchrotron ramping at 400 Hz. Following the practice in large 3 phase transformers and our own OPERA-2D simulations, joints are mitered to take advantage of the magnetic properties of the steel which are most effective in the direction in which the steel was rolled. Measurements with a Hysteresigraph 5500 and Epstein Frame show a high magnetic permeability which minimizes stored energy in the yoke so the magnet can ramp quickly with modest voltage. A power supply with a fast IGBT switch and a polypropylene capacitor was constructed. Coils are wound with 12 gauge copper wire which will eventually be cooled with with water flowing in stainless steel tubes. The magnetic field was measured with an F. W. Bell 5180 peak sensing Hall Probe connected to a Tektronics TDS3054B oscilloscope.
THPPD021	SC Magnet Development for SIS100 at FAIR	3545
	E.S. Fischer, A. Mierau, P. Schnizer GSI, Darmstadt, Germany
	Superconducting magnets have been constructed and tested for the SIS100 (Heavy Ion Synchrotron with a beam rigidity of 100 Tm) of the FAIR project. The requested high quality of the magnetic field as well as the fast periodic ramp of the SIS100 (2T, 1Hz) requires that any source of AC losses is tightly reduced by carefully optimising the 3D geometry of the yoke, choosing the appropriate iron material and minimising the eddy current loops. In addition optimal wire, cable and coil designs have been developed. The residual heat production will be reliable removed by an efficient cooling scheme. The beam pipe vacuum chamber must operate stably as a cryo-pump with surface temperatures below 20K. The electromagnetic, thermal and mechanical aspects were optimised and finally investigated based on physical analysis, supported by FEM calculations and dedicated tests. The results obtained on the main magnets were used for dedicated development of the corrector magnets and their effective integration in the complete cryo-magnet complex of the accelerator. We describe the features of the final magnets next to their optimised fields and present the construction status of the SIS100 magnets.
THPPD023	Solenoid Field Calculation of the SuperKEKB Interaction Region	3548
	N. Ohuchi, Y. Arimoto, M. Iwasaki, H. Koiso, A. Morita, Y. Ohnishi, K. Oide, M. Tawada, K. Tsuchiya, H. Yamaoka KEK, Ibaraki, Japan
	The SuperKEKB is the electron-positron collider, and the target luminosity is 8×1035 cm-2s−1, which is 40 times larger than the attained luminosity of KEKB. The beam final focus system consists of many types of superconducting magnets as 8 quadrupoles, 40 correctors and 4 compensation solenoids. These focusing magnets and correctors are designed to be operated inside the particle detector, Belle, and under the solenoid field of 1.5 T. From the analysis of beam optics, the solenoid field profile has serious impact on the beam vertical emittance. We designs the solenoid field profile along the Belle axis in a 2-dimensional model as the first step, and now we developed this model to the 3-dimensional calculation in detail. The solenoid field profiles along the both beam lines are generated with the combine solenoid field by the Belle solenoid and the compensation solenoids, and the magnetic components of the magnets and the magnetic shields on the beam lines. The model is very complicate. From the calculation results, we will discuss the influence on the beam optics and the final focusing magnet system.
THPPD024	Irradiation Effects in Superconducting Magnet Materials at Low Temperature	3551
	M.Y. Yoshida, M.I. Iio, S. Mihara, T. Nakamoto, H. Nishiguchi, T. Ogitsu, M. Sugano, K. Yoshimura KEK, Ibaraki, Japan M. Aoki, T. Itahashi, Y. Kuno, A. Sato Osaka University, Osaka, Japan Y. Kuriyama, Y. Mori, B. Qin, K. Sato, Q. Xu, T. Yoshiie Kyoto University, Research Reactor Institute, Osaka, Japan
	Superconducting magnets for high intensity accelerators and particle sources are exposed to severe radiation from beam collisions and other beam losses. Neutron fluence on the superconducting magnets for the next generation projects of high energy particle physics, such as LHC upgrades and the COMET experiment at J-PARC, is expected to exceed 1021 n/m2, which is close to the requirements on the fusion reactor magnets. Irradiation effects at low temperature in superconducting magnet materials should be reviewed to estimate the stability of the superconducting magnet system in operation and its life. The pion capture superconducting solenoids for the COMET experiment are designed with aluminum stabilized superconducting cable to reduce the nuclear heating by neutrons. Also, the heat is designed to be transferred in pure aluminum strips. Irradiation effects on the electrical conductance of aluminum stabilizer and other materials are tested at cryogenic temperature using the reactor neutrons. This paper describes the study on the irradiation effects for the magnet developments.
THPPD025	Expected and Measured Behaviour of the Tune in the LHC Operation at 3.5 TeV	3554
	N. Aquilina CERN, Geneva, Switzerland
	The tune of the Large Hadron Collider depends on the strength of the quadrupole magnets, the b2 component in the main dipoles plus the b3 component in the main dipoles and the sextupolar correctors via feed down in case of systematic misalignment. The magnetic model of the machine, based on a fit of magnetic measurements, has an intrinsic precision which can be estimated in a few units. During the first years of operation of the LHC, tune has been routinely measured and corrected through a feedback system. In this paper we reconstruct from the beam measurements and the settings of the feedback loop the evolution of tune during injection, ramp, and squeeze. This gives the obtained precision of the magnetic model of the machine with respect to quadrupolar and sextupolar components. At the injection plateau there is an unexpected large decay whose origin is not understood: we present the data, with the time constants and the dependence on the previous cycles, and compare to the magnetic measurements. During the ramp the tune drifts by about 0.05: this precision is related to the precision in tracking the quadrupolar field in the machine.
THPPD026	Splice Resistance Measurements in the LHC Main Superconducting Magnet Circuits by the New Quench Protection System	3557
	Z. Charifoulline, K. Dahlerup-Petersen, R. Denz, A.P. Siemko, J. Steckert CERN, Geneva, Switzerland
	The interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting cables stabilized by a copper bus bar. After the 2008 LHC incident, caused by a defective interconnection, a new layer of high resolution magnet circuit quench protection (nQPS) has been developed and integrated with the existing systems. It allowed mapping of the resistances of all superconducting splices during the 2009 commissioning campaign. Since April 2010, when the LHC was successfully restarted at 3.5TeV, every bus bar interconnection is constantly monitored by the nQPS electronics. The acquired data are saved to the LHC Logging Database. The paper will briefly describe the data analysis method and will present the results from the two years of resistance measurements. Although no splice was found with resistance higher than 3.3nOhm and no significant degradation in time was observed so far, the monitoring of splices will stay active till the end of LHC 3.5TeV run. The detected outliers will be repaired during the Splice Consolidation Campaign in 2013-2014.
THPPD027	Consolidation of the 13 kA Splices in the Electrical Feedboxes of the LHC	3560
	A. Perin, S. Atieh, O. Pirotte, R. Principe, D. Ramos, F. Savary, C.E. Scheuerlein, J.Ph. G. L. Tock, A.P. Verweij CERN, Geneva, Switzerland
	In 2008 a defective connection in one of the 13 kA dipole circuits of the LHC caused an electric breakdown that resulted in extensive damage in a sector of the accelerator. The investigation performed after the accident showed the necessity to consolidate the electrical splices of the 13 kA dipole and quadrupole circuits in order to operate the LHC at its nominal energy of 7 TeV. These circuits are powered through electrical feedboxes located at each end of the 8 sectors of LHC. In the feedboxes the current is routed from room temperature to the superconducting magnets along current leads and superconducting busbars and flows through at least two internal splices. These splices are based on the same technologies as the magnet to magnet ones but they are significantly different in terms of environment and configuration. As for the magnet to magnet splices, a consolidation will be necessary to operate them at nominal current. This paper presents an analysis of the properties of these splices and the technologies that will be used to consolidate them. The quality control provisions and the workflow to perform this operation during the first long shutdown of LHC are also presented.
THPPD028	Studies on the LHC Superconducting Circuits and Routine Qualification of Their Functionalities	3563
	M. Pojer, G. D'Angelo, R. Mompo, R. Schmidt, M. Solfaroli Camillocci CERN, Geneva, Switzerland
	The Large Hadron Collider (LHC) is systematically undergoing periods of maintenance stop (either 4-5 days stops or longer Christmas breaks), after which some of the superconducting circuits (or the totality of them) have to be re-commissioned to check the correct functionality of all powering and protection systems. Detailed procedures have been developed during the past few years and they have been optimized to increase powering tests efficiency, thus reducing beam downtime. The approach to the routine qualification of the LHC powering systems is described in this paper. During 2011 technical stops, some particular studies on the superconducting circuits were performed, to assess the quality of the superconducting splices of individually powered magnets and to study the quench propagation in the main magnet bus-bars. The methodology of these tests and some results are also presented.
THPPD029	Machine Availability at the Large Hadron Collider	3566
	M. Pojer, R. Schmidt, M. Solfaroli Camillocci, S. Wagner CERN, Geneva, Switzerland
	One of the most important parameters for a particle accelerator is its uptime, the period of time when it is functioning and available for use. In its second year of operation, the Large Hadron Collider (LHC) has experienced very high machine availability, which is one of the ingredients of its brilliant performance. Some of the strategies followed to increase MTBF are described in the paper. The approach of periodic maintenance stops, often questioned, is also discussed. Some considerations on the ideal length of a physics fill are also drawn.
THPPD030	Characterization of a Measurement System for Dynamic Effects in Large-aperture SC Quadrupole Magnets	3569
	S. Russenschuck, M. Bajko, M.C.L. Buzio, G. Deferne, O. Dunkel, L. Fiscarelli, D. Giloteaux, L. Walckiers CERN, Geneva, Switzerland
	A new measurement system, based on a large-diameter search-coil rotating in the superfluid helium, a fast digital integrator, a motor drive unit with sliprings, and a flexible software environment was devolped at CERN for the measurement of dynamic effects in superconducting magnets*. This system has made it possible the measure, with a resolution of up to 8 Hz, the multipole field errors due to superconductor magnetization and interstrand coupling currents. In the paper we will present the development and calibration of the measurement system, its installation in the vertical cryostat of CERN's recently refurbished test station, and its application to the US-LARP** built, 120-mm-aperture Nb3Sn quadrupole magnet (HQ) for the upgrade of the LHC insertion regions. * P. Arpaia et al. Active Comp. of Field Errors within ± 2 PPM in SC Magnets, NIM A, 2011 ** H. Felice et al. Design of HQ, a High Field Large Bore Nb3Sn Quad. Magnet for LARP, IEEE TAS, 2009
THPPD031	Measurement of the Residual Resistivity Ratio of the Bus Bars Copper Stabilizer of the 13 kA Circuits of the LHC	3572
	A. Apollonio, S.D. Claudet, M. Koratzinos, R. Schmidt, A.P. Siemko, M. Solfaroli Camillocci, J. Steckert, H. Thiesen, A.P. Verweij CERN, Geneva, Switzerland
	After the incident of September 2008, the operational beam energy of the LHC has been set to 3.5 TeV, since not all joints of the superconducting busbars between magnets have the required quality for 7 TeV operation. This choice is based on simulations to determine the safe current in the main dipole and quadrupole magnets, reproducing the thermal behavior of a quenched superconducting joint by taking into account all relevant factors that affect a possible thermal runaway. One important parameter of the simulation is the RRR (Residual Resistivity Ratio) of the copper stabilizer of the busbar connecting superconducting magnets. A dedicated campaign to measure this quantity for the main 13kA circuits of the LHC on all sectors was performed during the Christmas stop in December 2010 and January 2011. The measurement method as well as the data analysis and results are presented in this paper.
THPPD032	Consolidation of the LHC Superconducting Circuits: A Major Step towards 14 TeV Collisions	3575
	J.Ph. G. L. Tock, F.F. Bertinelli, F. Bordry, P. Fessia, R. Ostojic, A. Perin, H. Prin, F. Savary, C.E. Scheuerlein, H.H.J. Ten Kate, A.P. Verweij, G.P. Willering CERN, Geneva, Switzerland
	Following the incident in one of the main dipole circuits of the Large Hadron Collider (LHC) in September 2008, a detailed analysis of all magnet circuits has been performed by a dedicated task force. This analysis has revealed several critical issues in the design of the 13 kA splices between the main LHC cryomagnets. These splices have to be consolidated before increasing the beam energy above 4 TeV and to operate the LHC close to 7 TeV per beam. The design for the consolidated 13 kA splices is now complete and has been reviewed by an international committee of experts. In the process, all types of superconducting circuits have been thoroughly screened and several important recommendations were established. They were critically assessed and the resulting actions are presented. In addition to the work on the 13 kA splices, other interventions will be performed during the first long shut-down of the LHC to consolidate globally all the superconducting circuits. The associated quality controls have been defined and are detailed in the operations workflow. The schedule constraints, repairs production rate, available space and resources are presented as well.
THPPD033	Using Permanent Magnets to Boost the Dipole Field for the High-energy LHC	3578
	F. Zimmermann CERN, Geneva, Switzerland Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579. The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb-Ti, Nb3Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability.
THPPD034	Quench Performance and Field Quality of 90-mm Nb3Sn Quadrupoles of TQC Series	3581
	G. Chlachidze, N. Andreev, R. Bossert, J. DiMarco, V. Kashikhin, M.J. Lamm, A. Nobrega, I. Novitski, M.A. Tartaglia, G. Velev, A.V. Zlobin Fermilab, Batavia, USA
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy A series of accelerator quality Nb3Sn quadrupole models has been developed, fabricated and tested at Fermilab. The magnet design includes a 90 mm aperture surrounded by four two-layer Nb3Sn coils supported by a stainless steel collar, iron yoke and stainless steel skin. This paper describes the design and fabrication features of the quadrupole models and presents the summary of model tests including quench performance and field quality at 4.5 and 1.9 K.
THPPD035	Magnets for Interaction Regions of a 1.5×1.5 TeV Muon Collider	3584
	V. Kashikhin, Y. Alexahin, N.V. Mokhov, A.V. Zlobin Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The updated IR optics and conceptual designs of large aperture superconducting quadrupole magnets for a muon collider with a c.o.m. energy of 3 TeV and an average luminosity of 4·1034 cm-2 s-1 are presented. All magnets are based on the Nb3Sn superconductor and designed to provide an adequate operation field gradient in the given aperture with the critical current margin required for reliable machine operation. Special dipole coils were added to quadrupole designs to provide ~2 T bending field and thus facilitate chromaticity correction and dilute decay electron fluxes on the detector. Magnet cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. Magnet parameters are reported and compared with the requirements. Energy deposition calculations with the MARS code have allowed to optimize parameters of inner absorbers, collimators in interconnect regions and Machine-Detector Interface.
THPPD036	High-Field Combined-Function Magnets for a 1.5×1.5 TeV Muon Collider Storage Ring	3587
	V. Kashikhin, Y. Alexahin, N.V. Mokhov, A.V. Zlobin Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy A new storage ring lattice based on combined function high-field magnets and conceptual designs of superconducting magnets with dipole and quadrupole coils for a muon collider with a c.o.m. energy of 3 TeV and an average luminosity of 4x1034 cm-2 s-1 are presented. Magnets are designed to provide the required focusing field gradient and bending field in the aperture with the appropriate operation margin. Magnets have large apertures to provide an adequate space for internal absorbers, vacuum insulation, beam pipe, and helium channel. Coil cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. Magnet parameters are reported and compared with the requirements. Energy deposition calculations with the MARS code have allowed to optimize parameters of inner absorbers and collimators in interconnect regions, thus reducing peak power density and dynamic loads to the tolerable levels.
THPPD037	Design Studies of a Dipole with Elliptical Aperture for the Muon Collider Storage Ring	3590
	M.L. Lopes, V. Kashikhin, J.C. Tompkins, A.V. Zlobin Fermilab, Batavia, USA R.B. Palmer BNL, Upton, Long Island, New York, USA
	Funding: Work supported partially by US-MAP and by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The requirements and operating conditions for superconducting magnets used in a Muon Collider Storage Ring are challenging. About one third of the beam energy is deposited along the magnets by the decay electrons. As a possible solution an elliptical tungsten absorber could intercept the decay electrons and absorb the heat limiting the heat load on superconducting coils to the acceptable level. In this paper we describe the main design issues of dipoles with an elliptical aperture taking into consideration the field and field quality. The temperature margin and the forces in the coils are presented as well.
THPPD038	Measurements of the Persistent Current Decay and Snapback Effect in Nb3Sn Accelerator Prototype Magnets at Fermilab	3593
	G. Velev, G. Chlachidze, J. DiMarco, V. Kashikhin Fermilab, Batavia, USA
	In recent years, Fermilab has been performing an intensive R&D program on Nb3Sn accelerator magnets. This program has included dipole and quadrupole magnets for different programs and projects, including LARP and VLHC. A systematic study of the persistent current decay and snapback effect in the fields of these magnets was executed at the Fermilab Magnet Test Facility. The decay and snapback were measured under a range of conditions including variations of the current ramp parameters and flattop and injection plateau durations. This study has mostly focused on the dynamic behavior of the normal sextupole and dodecapole components in dipole and quadrupole magnets respectively. The paper summarizes the recent measurements and presents a comparison with previously measured NbTi magnets.
THPPD039	Magnetic Analysis of a Single-Aperture 11T Nb3Sn Demonstrator Dipole for LHC Upgrades	3596
	B. Auchmann, M. Karppinen CERN, Geneva, Switzerland V. Kashikhin, A.V. Zlobin Fermilab, Batavia, USA
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The planned upgrade of the LHC collimation system foresees additional collimators to be installed in the dispersion suppressor areas around points 2, 3, and 7. The necessary longitudinal space for the collimators could be provided by replacing some 8.33-T 15-m-long NbTi LHC main dipoles with shorter 11-T Nb3Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility, in 2011 Fermilab and CERN started a joint R&D program with the goal of building a 5.5-m-long twin-aperture dipole prototype suitable for installation in the LHC by 2014. The first step of this program is the development of a 2-m-long single-aperture demonstration dipole with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and 60-mm bore with ~20% margin. This paper presents the results of magnetic analysis of the single-aperture Nb3Sn demonstrator dipole for the LHC collimation system upgrade.
THPPD040	Quench Protection Analysis of a Single-Aperture 11T Nb3Sn Demonstrator Dipole for LHC Upgrades	3599
	A.V. Zlobin, I. Novitski, R. Yamada Fermilab, Batavia, USA
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The planned upgrade of the LHC collimation system foresees additional collimators to be installed in the dispersion suppressor areas around points 2, 3, and 7. The necessary longitudinal space for the collimators could be provided by replacing some 8.33-T 15-m-long NbTi LHC main dipoles with shorter 11-T Nb3Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility, in 2011 Fermilab and CERN started a joint R&D program with the goal of building by 2014 a 5.5-m-long twin-aperture dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2-m-long single-aperture demonstration dipole with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and 60-mm bore with ~20% margin. This paper summarizes the results of quench protection analysis of the single-aperture Nb3Sn demonstrator dipole for the LHC collimation system upgrade.
THPPD041	Evaluation and Implementation of High Performance Real-Time Signal Processing For Rayleigh Scattering Based Quench Detection for High Field Superconducting Magnets	3602
	G. Flanagan, R.P. Johnson Muons, Inc, Batavia, USA W.K. Chan, J. Schwartz North Carolina State University, Raleigh, North Carolina, USA Q. Ruan, D. Schmidt, L. Wenzel, C. Wimmer National Instruments, Austin, USA
	Funding: Supported in part by SBIR Grant 4747 · 11SC06251 YBCO coated conductors are one of the primary options for generating the high magnetic fields needed for future high energy physics devices. Due to slow quench propagation, quench detection remains one of the primary limitations to YBCO magnets. Fiber optic sensing, based upon Rayleigh scattering, has the potential for quench detection with high spatial resolution. This paper discusses the potential of multicore CPU's and FPGA’s to accelerate the signal processing demands associated with Rayleigh scattering based quench detection systems in a real-time environment.
THPPD042	High Radiation Environment Nuclear Fragment Separator Dipole Magnet	3605
	S.A. Kahn Muons, Inc, Batavia, USA R.C. Gupta BNL, Upton, Long Island, New York, USA
	Funding: Supported in part by STTR Grant 4746 · 11SC06273 Magnets in the fragment separator region of the Facility for Rare Isotope Beams (FRIB) would be subjected to extremely high radiation and heat loads. Critical elements of FRIB are the dipole magnets which select the desired isotopes. Since conventional NiTi and Nb3Sn superconductors must operate at ~4.5 K, the removal of the high heat load generated in these magnets with these superconductors would be difficult. The coils for these magnets must accommodate the large curvature from the 30° bend that the magnets subtend. High temperature superconductor (HTS) have been shown to be radiation resistant and can operate in the 20-50 K temperature range where heat removal is an order of magnitude more efficient than at 4.5 K. Furthermore these dipole magnets must be removable remotely for servicing because of the extremely high radiation environment. This paper will describe the magnetic and conceptual design of these magnets.
THPPD043	Radiation-tolerant Multipole Correction Coils for FRIB	3608
	S.A. Kahn Muons, Inc, Batavia, USA R.C. Gupta BNL, Upton, Long Island, New York, USA
	Multipole correction insert coils with significant field strength are required inside the large aperture superconducting quadrupole magnets in the fragment separator section of the Facility for Rare Isotope Beams (FRIB). Correction coils made with copper do not create the required field and conventional low temperature superconductors are not practical in the fragment separator magnets which will operate at 40-50 K. The correction coils should be made of HTS as the main quadrupole coils are. There is a significant advantage to using HTS in these coils as it can withstand the high radiation and heat load that will be present. This paper will describe an innovative design suitable for coils with the complex end geometry of cylindrical coils. We will look at the forces on the corrector coils from the mail quadrupole fields and anticipate possible coil distortions.
THPPD044	Fabrication and Testing of Curved Test Coil for FRIB Fragment Separator Dipole	3611
	S.A. Kahn Muons, Inc, Batavia, USA J. Escallier, R.C. Gupta, G. Jochen, Y. Shiroyanagi BNL, Upton, Long Island, New York, USA
	Funding: Supported in part by SBIR Grant 4746 · 11SC06273 A critical element of the fragment separator region of the Facility for Rare Isotope Beams (FRIB) is the 30° dipole bend magnet. Because this magnet will be subjected to extremely high radiation and heat loads, operation at 4.5 K would not be possible. High temperature superconductors which have been shown to be radiation resistant and can operated in the 30-50 K temperature range which is more effective for heat removal. An efficient design for this magnet would make use of coils that follow the curvature of the magnet. Winding curved coils with negative curvature are difficult as the coil tends to unwind during the process. As part of an R&D effort for this magnet we are winding a ¼ scale test coil for this magnet with YBCO conductor and are testing it at 77 K. This paper will discuss the winding process and the test results of this study.
THPPD045	High Temperature Superconducting Magnets for Efficient Low Energy Beam Transport Systems	3614
	J.H. Nipper, G. Flanagan, R.P. Johnson Muons, Inc, Batavia, USA M. Popovic Fermilab, Batavia, USA
	Modern ion accelerators and ion implantation systems need very short, highly versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and continuous operation requires LEBT designs to be simple and robust. The energy efficiency of available high temperature superconductors (HTS), with efficient and simple cryocooler refrigeration, is an additional attraction. Innovative, compact LEBT systems based on solenoids designed and built with high-temperature superconductor will be developed using computer models and prototyped. The parameters will be chosen to make this type of LEBT useful in a variety of ion accelerators, ion implantation systems, cancer therapy synchrotrons, and research accelerators, including the ORNL SNS. The benefits of solenoids made with HTS will be evaluated with analytical and numerical calculations for a two-solenoid configuration, as will be used in the SNS prototype LEBT that will replace the electrostatic one at SNS, and a single solenoid configuration, as was proposed for the Fermilab proton driver that will be most applicable to ion implantation applications.
THPPD048	15+ T HTS Solenoid for Muon Accelerator Program	3617
	Y. Shiroyanagi, R.C. Gupta, P.N. Joshi, H.G. Kirk, R.B. Palmer, S.R. Plate, W. Sampson, P. Wanderer BNL, Upton, Long Island, New York, USA D.B. Cline UCLA, Los Angeles, California, USA J. Kolonko, R.M. Scanlan, R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: This work is supported by the U.S.Department of Energy under Contract No. DE-AC02-98CH10886 and SBIR contract DOE Grant Numbers DE-FG02-07ER84855 and DE-FG02- 08ER85037. This paper will present the construction and test results of a ~10 T insert coil solenoid which is part of a proposed ~35 T solenoid being developed under a series of SBIR contracts involving collaboration between Particle Beam Lasers (PBL) and Brookhaven National Laboratory. The solenoid has an inner diameter of 25 mm, outer diameter of ~95 mm and a length of ~70 mm. It consists of 14 single pancake coils made from 4 mm wide 2G HTS conductor from SuperPower Inc., co-wound with a 4 mm wide, 0.025 mm thick stainless steel tape. These are paired into 7 double pancake coils. Each double pancake coil has been individually tested at 77 K before assembly in a complete solenoid. The solenoid is nearly ready for a high field test at ~4K.
THPPD049	Conceptual Design of a Superconducting Septum for FFAGs	3620
	H. Witte BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom K.J. Peach, T. Yokoi JAI, Oxford, United Kingdom
	Funding: This work was supported by STFC grant ST/G008531/1 and EPSRC Grant EP/E032869/1. The fixed magnetic field in FFAG (Fixed Field Alternating Gradient) accelerators means that particles can be accelerated very rapidly. This makes them attractive candidates for many applications, for example for accelerating muons for a neutrino factory or for charged particle therapy (CPT). To benefit fully from this the particles have to be extracted at the same rate. In combination with the high magnetic rigidity of the particles this represents a significant challenge, especially where variable energy extraction is required, which implies extraction at variable radius. This paper presents a conceptual design of a 4T superconducting septum for the PAMELA accelerator, which is an FFAG for a combined proton/carbon ion therapy facility. The field in the septum is varied as a function of the horizontal position, which allows variable energy extraction without the need for sweeping of the magnetic field.
THPPD050	Fast Ramping Arbitrary Waveform Power Supplies for Correction Coils in a Circular Electron Accelerator	3623
	A. Dieckmann, A. Balling, O. Boldt, F. Frommberger, W. Hillert, W. Lindenberg ELSA, Bonn, Germany
	New fast ramping power supplies working in pulsed bridge technology upgrade the existing Corrector System at ELSA. Current changes of ±0.8 A/msec are achieved. The newly developed CAN-Bus Interface allows linear interpolation of up to 250 support points with minimal time steps of 1msec. The first stage uses 24 power supplies to improve the position of the beam orbit in the horizontal plane using dipole correction coils. It will be extended to include the vertical plane with new corrector coils in the near future. This poster describes the operating principles of the power supply and the interface.
THPPD051	New Power Supply of the Injection Bump Magnet for Upgrading the Injection Energy in the J-PARC 3-GeV RCS	3626
	T. Takayanagi, N. Hayashi, M. Kinsho, N. Tani, T. Togashi, T. Ueno JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	With the energy upgrading of LINAC (Linear accelerator) to 400 MeV in the J-PARC (Japan Proton Accelerator Research Complex), a new power supply of the injection bump magnet has been designed for the 3-GeV RCS (Rapid Cycling Synchrotron). The new power supply is composed with the capacitor bank which has function to form the output current pattern. This power supply is a commutation strategy using the electrical charge and discharge of the capacitor, and the frequency of the switch that becomes the source of the noise is a little. Comparing to the conventional switching-type power supply, this power supply is switched only twice for the pattern formation. Thus, the ripple due to the switching can be expected to be much lower. The 1/16 scale model was manufactured and the characteristics was evaluated. This paper summarizes the design parameter and the experimental result of the new power supply.
THPPD052	Operation and Current Status of Injection, Extraction, Kicker Magnet and the Power Supply for J-PARC 3 GeV RCS	3629
	M. Watanabe, N. Hayashi, Y. Shobuda, K. Suganuma, T. Takayanagi, T. Togashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	3-GeV RCS (Rapid Cycling Synchrotron) at High Intensity Proton Accelerator Facility (J-PARC) have started for 24-hour operation with repetition rate of 25 pps in February, 2009. Kicker power supply system which uses thyratrons switches is used for extraction of the proton beam. There were many troubles for unstable operation of the thyratrons just after beam commissioning started. Recently, however, the operations were improved and the failure rate was reduced to approximately 0.1 % in October 2010. After the earthquake on March 11, 2011, the injection and extraction magnets, power supplies, the cables and the bus-duct have been checked. Insulation resistance test, impedance test were performed. Reflected wave measurements by the low-level and high-power pulse of the kicker magnets were performed. Visual checks by a fiber endoscope were also performed in the kicker magnets. The results of the measurements and the checks were all not in the problem.
THPPD053	Study on Eddy Current Power Losses in Insulated Core Transformer Primary Coil	3632
	L. Yang, X. Liu, Y.Q. Xiong, J. Yang Huazhong University of Science and Technology (HUST), Wuhan, People's Republic of China T. Yu HUST, Wuhan, People's Republic of China
	Insulated core transformer (ICT) high-voltage DC power supply is widely used in electron beam accelerator. With air gap in ICT, the reluctance of magnetic circuit is larger than other transformers, and the transverse magnetic flux leakage around the primary coil is more serious. Because the magnetic flux on the radial direction of coil cannot be ignored, the eddy current loss on the wire should be discussed. In this paper, simulation and analysis of the eddy current loss is presented. The relationship between the sizes of the coil wire is also discussed. An optimal design of the primary coil is shown.
THPPD054	Low Current Bipolar Magnet Power Supply System at the PLS-II Storage Ring	3635
	S.-C. Kim, J.Y. Huang, K.R. Kim, S.H. Nam, S. Shin, Y.G. Son, C.W. Sung PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: * This work is supported by the Ministry of Education, Science and Technology, Korea. Lattice of the Storage Ring (SR) is changed from TDB to DBA, and beam energy is enhanced from 2.5 GeV to 3.0 GeV at the Pohang Light Source upgrade (PLS-II). At the PLS-II, Magnet Power Supplies (MPS) were newly designed according to magnet specification of the PLS-II. All MPSs are adopted switching type power conversion technology. Low current bipolar MPSs for vertical corrector(VC), horizontal corrector(HC), fast corrector(FC), aux.-quadrupole(AQ), skew(SK) and dipole trim coil(TR) magnets are H-bridge type. All MPSs are performed less than ± 10 ppm output current stability and adopted full digital controller. Except vertical corrector MPSs, all unipolar and bipolar MPSs are developed as embedded EPICS IOC. In this paper, we report on the development and characteristics of the bipolar MPS for the PLS-II Storage Ring.
THPPD055	High Current Unipolar Magnet Power Supply System at the PLS-II Storage Ring	3638
	S.-C. Kim, J.Y. Huang, K.R. Kim, S.H. Nam, S. Shin, Y.G. Son, C.W. Sung PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This work is supported by the Ministry of Education, Science and Technology, Korea. Lattice of the Storage Ring (SR) is changed from TDB to DBA, and beam energy is enhanced from 2.5 GeV to 3.0 GeV at the Pohang Light Source upgrade (PLS-II). At the PLS-II, Magnet Power Supplies (MPS) were newly designed according to magnet specification of the PLS-II. All MPSs are adopted switching type power conversion technology. High current unipolar MPSs for bending(BD), main-quadrupole(MQ), sextupole(ST) and septum(SP) magnet are parallel operation type of unit stack buck type power supply. Unit stack of unipolar MPS has capability maximum 250A and operation 10kHz. BD and MQ MPS are adopted four stack as each stack 90degree phase shift switching, and have capability maximum 1000 A. ST MPS is adopted two stack as each stack 180degree phase shift switching, and have capability maximum 500 A. SP MPS is adopted single, and have capability maximum 250 A. All unipolar MPSs are developed as full digital controller, embedded EPICS IOC and operated less than ± 10ppm current stability. In this paper, we report on the development and characteristics of the high current unipolar MPS for the PLS-II SR.
THPPD056	Performance of the Crowbar of the LHC High Power RF System	3641
	G. Ravida, O. Brunner, D. Valuch CERN, Geneva, Switzerland
	During operation, the LHC high power RF equipment such as klystrons, circulators, waveguides and couplers have to be protected from damage caused by electromagnetic discharges. Once ignited, these arcs grow over the full height of the waveguide and travel towards the RF source. The burning plasma can cause serious damage to the metal surfaces or ferrite materials. The "crowbar" protection system consists of an arc current detector coupled with a fast high voltage switch in order to rapidly discharge the main high voltage components such as cables and capacitors and to shut down the high voltage source. The existing protection system, which uses a thyratron for grounding the high voltage circuit, has been installed in the LHC about 20 years ago. The problem of "faulty shots" appears due to the higher energy of LHC compared to LEP, which may lead to unnecessary stops of the LHC due to the crowbar system. This paper presents two approaches under consideration to improve the thyratron’s performance and to use a solid state thyristor in high energy environment. The main objectives will be dissipate as little energy as possible in the arc and avoid "faulty shots".
	Poster THPPD056 [0.703 MB]
THPPD058	Reduction of Conductive EMI Noise Resulted from the Commercial Power Supply	3644
	C.S. Chen, C.K. Chan, J.-C. Chang, Y.L. Chu, K.H. Hsu, C.Y. Kuo, Y.-H. Liu, C.S. Yang NSRRC, Hsinchu, Taiwan
	Almost every electronic equipment must be connected to power system. Because of the complexity of power lines, the reduction of conductive electro-magnetic interference (C-EMI) plays an important role in precise measurements. In this paper, a line impedance stabilization network (LISN) was built up to get the spectrum from power lines. After several measurements by some commercial power supplies, it is found that some of these power supplies induce effectively C-EMI into power lines, even if a passive filter is bound in power line. These noises may influence numerous equipments in a local area near the sources. Therefore, how to choose a suitable filter is a decisive factor to reduce the magnitude of C-EMI.
THPPD059	Conductive EMI Reduction to Kicker Magnet Power Supply in NSRRC	3647
	Y.-H. Liu, J.-C. Chang, C.S. Chen, H.H. Chen, J.-R. Chen NSRRC, Hsinchu, Taiwan
	The purpose of this paper is to estimate and reduce the conductive Electromagnetic Interference (EMI) from kicker magnet power supply in TLS. A LISN system was conducted to measure the EMI spectrum of kicker power supply. The EMI noise exceeded FCC standards in some frequency range especially during kicker firing. Reducing EMI level by using different EMI filters were applied. Double pi filter was more efficient than single pi filter. After using filter, the conducted EMI could diminish lower than FCC class B. The experimental results will provide useful information to future TPS pulsed magnet design.
THPPD061	Optimal Design for Resonant Power Transformer	3650
	C.-Y. Liu, D.-G. Huang, J.C. Huang NSRRC, Hsinchu, Taiwan
	The energy and dc to dc conversion of the resonant transformer are required to achieve optimal design and working condition of the resonant region frequency. To meet this requirement, the core loss will be checked first by data book for calculation. Using a reliable precise instrument is needed to scan the resonant cure of the resonant transformer as we designed the resonant cure. We calculated the conduction loss in second design step. We design a resonant transformer which the conduction loss equal core loss does not meet optima design, because the core loss is very high when the transformer works in resonant frequency. Thus, we only reduce the conduction loss is optima design aspect.
THPPD062	Development of Digital-controlled Corrector Magnet Power Converter with Shunt as a Current Sensing Component	3653
	B.S. Wang, J.C. Huang, K.-B. Liu NSRRC, Hsinchu, Taiwan
	In Taiwan light source (TLS), Bira MCOR power converter modules are adopted as the corrector magnet power converters, the output is regulated by analog PWM IC that caused nonlinear behavior at zero cross and the adjustment of compensator for difference kind of magnet load is inconvenient. In the thesis the analog regulation IC is replaced by a fully digital regulation control circuit to realize digital regulation control converter. With plugging the home-made fully DSP regulation control cards into MCOR30 that the current sensing component is a shunt, the switching losses of MOSFET was reduced and the cost that the component of current sense. With the fully digital regulation control circuit, the parameter of the compensator for different magnet load is very easy to adjustment. In addition, the feasibility and validity of MOSFET switching theorem is simulated with Matlab simulink and the performance of this power converter is verified, the output current ripple of this power converter could be lower than 10ppm, which is beyond the requirement of current TLS corrector power converter and qualified to be used in the future TPS facility.
THPPD063	Zero Voltage Switching of Two-switch Flyback-Forward Converter	3656
	J.C. Huang, K.-B. Liu, Y.S. Wong NSRRC, Hsinchu, Taiwan
	The traditional pulse-width-modulated flyback converter power switch has serious electromagnetic interference (EMI) and lower conversion efficiencies problems due to the hard-switching operations. This paper produces a zero voltage switching of flyback-forward converter with an active-clamp circuit, the traditional pulse-width-modulated flyback converter with a active clamp circuit to achieve zero-voltage-switching (ZVS) at both main and auxiliary switches, the active-clamp circuit can reduce most of switching loss and voltage spikes across the switches and improve the overall efficiency of the converter. The theoretical analysis of soft switching flyback-forward converter with an active-clamp circuit is verified exactly by a prototype of 50W with 100V input voltage, 5V output voltage and 30kHz operated frequency.
THPPD064	The Compensator Design of the Fully Digital Controlled Corrector Magnet Power Converter by Using LabView as the Development Tools	3659
	B.S. Wang, J.C. Huang, K.-B. Lin NSRRC, Hsinchu, Taiwan
	The auto-tuning of PI-compensator for power converter is fulfilled by using the LabVIEW. The current error signals of the power converter with different PI compensating parameters are transferred by RS-232 or Ethernet communication interface from DSP card into LabVIEW and FFT analysis are calculated. The FFT analysis are stored in the batch file for further numerical analysis and the parameters with the best response is recognized which will be set as the default PI parameters. In addition, the feasibility and validity of auto-tuning theorem was verified by measuring the long-term stability of output current and during the long-term measuring period the stability and ripple current of the power converter are observed. In this thesis, the fully digital regulation controlled corrector magnet power converter with a shunt as the current sensing component was used as the developing platform. The auto-tuning theorem was realized and applied to the compensator of the power converter, and the best output current response of the power converter was fulfilled.
THPPD066	High Precision Programmable of TPS Quadrupole Magnet Power Supply	3662
	Y.S. Wong, J.C. Huang, K.-B. Liu, W.S. Wen NSRRC, Hsinchu, Taiwan
	In 1993, the first of Taiwan light source was held on October 16. First beam stored in the storage ring and facility at synchrotron radiation research centre (SRRC) was opened to users and the full energy injection to 1.5Gev after seven years. In 2007, the president of Executive Yuan Taiwan had been announcement to set up a third-generation synchrotron radiation. Taiwan Photon Source (TPS) project total budget of NT6, 885 million from 2007~ 2013. TPS project will improve technical capability to build to3.3Gev electron energy. Totally had been installed 1032sets of magnet power supplies for the storage ring and 152 sets for the injector. In the future, Taiwan photon source set up complete and operation, it will offer one of the world's brightest synchrotron x-ray sources.
THPPD067	Performance of Kicker Pulsers for TPS Project	3665
	C.-S. Fann, C.-T. Chen, K.T. Hsu, S.Y. Hsu, J.C. Huang, K.-K. Lin, K.-B. Liu, H.M. Shih, K.L. Tsai NSRRC, Hsinchu, Taiwan
	A set of kicker power suppliers has been designed and fabricated for storage ring beam injection of the Taiwan Photon Source (TPS) project. In order to fulfill the requirements, the performance of the designed units has been bench tested and the results are examined. The matching in four pulsers, the pulse-to-pulse stability and the time jitter are specified according to the beam injection requirements. The engineering evaluation and the measurement results are briefly discussed.
THPPD068	Precision sbRIO-based Magnet Power Supply Annunciator and Control Interface for Accelerator Control Systems	3668
	S. Cohen, P. Kowalski Bira, Albuquerque, New Mexico, USA
	Beam physicists require more data and performance information that is commonly provided by the modern switch-mode power supplies installed at these facilities. We describe single-board RIO (sbRIO)-based* power-supply controller that provides the functionality required for integrating these supplies into control and safety systems at these facilities. The unit allows local control and presents a visual representation of the operational status of each power supply, independent digitized read back of power-supply output current, EPICS control via a Channel Access (CA) server, status information and electrical connections to independent and redundant accelerator safety systems. * National Instruments, Austin, TX, http://www.ni.com/singleboard/ .
THPPD069	Adjustable Pulse Duration Fast Kicker for the CRYRING Storage Ring	3671
	J.-P. Lavieville, P. Lebasque SOLEIL, Gif-sur-Yvette, France W. Beeckman, O. Cosson Sigmaphi, Vannes, France
	The CRYRING storage ring of the Manne Siegbahn Laboratory (MSL, Stockholm) shall be moved to become part of FLAIR accelerators complex in Darmstadt to be used for deceleration of antiprotons and charged ions. That needs an upgrade to adapt it to the full energy range (30MeV – 0.13 MeV) of its future exploitation. SIGMAPHI, in close collaboration with SOLEIL light Source, is in charge of new fast injection and extraction magnets kickers and their pulsed power supplies. The injection will be done at maximum energy (30 MeV) while the extraction need to cover the full energy range (30 MeV – 0.13 MeV) that requires a continuous adjustment capability on the pulse duration and on the deviation amplitude. The development made specifically for the CRYRING kickers is based on a new design involving two different pulsed power supplies, each one managing either the fast rise time or the current flat top. Using solid state switches allows adapting simultaneously the pulse duration and its amplitude. This contribution presents the specific scheme and the development of a kicker system working up to 20 kV with pulse duration from 1.62 μs to 16.3 μs with transient times less than 300 ns.
THPPD070	Design of High Power Pulse Modulator for Driving of Twystron used in S-band Linear Accelerator	3674
	V. Aslani, F. AbbasiDavani, F. Ghasemi, M.Sh. Shafiee sbu, Tehran, Iran
	This design related to an s-band linear accelerator that the main tube and buncher of it have been made. RF power supply is used in this accelerator tube made up of a Twystron with 2.5 MW peak power and frequency band width 2.9~3.1 GHz. This paper offers the design of modulator for this RF amplifier. This modulator design uses solid-state method and is under construction with specification of ; Adjustable voltage from 0 to 120 kV, adjustable pulse width 2 until7μsecond, adjustable repetition rate 80-120 Hz ,ripple less than0.25% and efficiency up 80 percent. This system designed with series of 6 modules that each of them provides 5kV and IGBT switches that transform the voltage on the pulse transformer.
THPPD071	A Compact Switching Power Supply utilizing SiC-JFET for the Digital Accelerator	3677
	K. Okamura, T. Iwashita, K. Takayama, M. Wake KEK, Ibaraki, Japan K. Takaki, M. Toshiya Iwate university, Morioka, Iwate, Japan
	New induction synchrotron system using an induction cell has been developed and constructed at KEK*. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as Digital Accelerator**. In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates because it has ultrafast switching speed and voltage blocking capability. Therefore, we have developed a new device to substitute existing silicon MOSFET and succeeded to operate with 1 MHz – 1 kV – 27 A condition***. Then we designed and constructed a ultra compact full bridge switching power supply utilizing those devices as a next step. Design and test results will be presented in the conference. * T. Iwashita et al., KEK Digital Accelerator, Phys. Rev. ST-AB 14, 071302 (2011) ** K. Takayama et al., in Proc. of IPAC’11, pp 1920-1922 *** K. Okamura et al., in Proc. of IPAC’11, pp 3400-3402
THPPD072	Performance Optimization of the Stacked-Blumlein	3680
	L.W. Zhang, J. Li, W.D. Wang CAEP/IFP, Mainyang, Sichuan, People's Republic of China Y. Li CAEP, Mainyang, Sichuan, People's Republic of China
	Funding: This work was supported by the National Natural Science Foundation of China (11035004) For the applications of the Dielectric Wall Accelerator (DWA), the stacked Blumlein pulse generator comprised of parallel-plate transmission lines is being developed. The peak output voltage of the stacked Blumlein will be much lower than expected due to the parasitic coupling among the individual pulse forming lines of the Blumlein stack. The finite difference time domain method is used to model the stacked Blumlein structure and determine the outputs. We present the optimization of a 20-Blumleins-stack in this paper. The results for different structures are discussed.
THPPD073	Development and Management of the Modulator System for PLS-II 3.0 GeV Electron Linac	3683
	S.H. Kim, J.Y. Huang, S.J. Kwon, B.-J. Lee, Y.J. Moon, S.H. Nam, S.S. Park, S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This work is supported by MEST(Ministry of Education, Science and Technology) and POSCO(Pohang Steel and Iron Company). The Pohang Accelerator Laboratory (PAL) had started the upgrade project (called PLS-II) of the Pohang Light Source (PLS) from 2009 for increasing its energy from 2.5 GeV to 3 GeV and changing the operation mode from fill-up to top-up mode. Top-up mode operation requires high energy stability of the linac beam and machine reliability in the linac modulator systems. For providing the additional 0.5 GeV energy from the 2.5 GeV PLS linac, we added four units of the modulator system. We have two different types of the pulse modulator system for using existing pulse modulators, thyristor control type, in the upgrade project (PLS-II). The two types are thyristor control type and inverter power type. In the thyristor control type, a de-Qing system controls the modulator pulse forming network (PFN) charging voltage stability, and in the inverter power supply type, CCPS provides highly stable charging voltage to the modulator. We will present development and management of the pulse modulator system for obtaining machine reliability and stability from 3.0 GeV linac.
THPPD074	Effect of a Metallized Chamber upon the Field Response of a Kicker Magnet: Simulation Results and Analytical Calculations	3686
	M.J. Barnes, M.G. Atanasov, T. Fowler, T. Kramer, T. Stadlbauer CERN, Geneva, Switzerland
	Metallized racetrack vacuum chambers will be used in the pulsed magnets of the Austrian cancer therapy and research facility, MedAustron. It is important that the metallization does not unduly degrade field rise and fall times or the flattop of the field pulse in the pulsed magnets. This was of particular concern for a tune kicker magnet, which has a specified rise and fall time of 100 ns. The impact of the metallization, upon the transient field response, has been determined by finite element method (FEM) simulations: the dependency of the field response to the metallization thickness and resistivity are presented. Formulae for the field response, which permit the use of a ramped transient excitation current, are presented: thus the coating thickness and resistivity can be determined which result in a maximum permissible field attenuation and delay for a given current rise time. In addition, results of simulations of the effect of a magnetic brazing collar, located between the ceramic vacuum chamber and flange, are reported.
THPPD075	Design and Measurements of a Fast High-voltage Pulse Generator for the MedAustron Low Energy Transfer Line Fast Deflector	3689
	T. Fowler, M.J. Barnes, T. Kramer, F. Müller, T. Stadlbauer CERN, Geneva, Switzerland
	MedAustron, a centre for ion-therapy and research, will comprise an accelerator facility based on a synchrotron for the delivery of protons and light ions for cancer treatment. The Low Energy Beam Transfer line (LEBT) to the synchrotron contains an electrostatic fast deflector (EFE) which, when energized, deviates the continuous beam arriving from the ion source onto a Faraday Cup: the specified voltage is ±3.5 kV. De-energizing the EFE for variable pulse durations from 500 ns up to d.c. allows beam passage for multi-turn injection into the synchrotron. To maintain beam quality in the synchrotron, the EFE pulse generator requires rise and fall times of less than 300 ns between 90 % of peak voltage and a ±1 V level. To achieve this, a pulsed power supply (PKF), with high voltage MOSFET switches connected in a push-pull configuration, will be mounted in close proximity to the deflector itself. A fast, large dynamic range monitoring circuit will verify switching to the ±1 V level and subsequent flat bottom pulse quality. A prototype will be installed in the injector test stand in 2012; this paper presents the design and first measurements of the PKF and its monitoring circuit.
THPPD076	Evaluation of Components for the High Precision Inductive Adder for the CLIC Damping Rings	3692
	J. Holma, M.J. Barnes CERN, Geneva, Switzerland
	The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat, high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than ±0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. In addition to semiconductors working in their saturated region, semiconductors working in their linear region are needed for applying analogue modulation techniques. Simulations have been carried out to define component specifications for the inductive adder: this paper reports the results of tests and measurements of various components.
THPPD077	ISIS Injector 2 MW Pulsed RF System Power Supply Upgrade	3695
	R.J. Anderson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom M. Keelan STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The ISIS pulsed neutron and muon source uses a 4-stage 70 Mev linear accelerator powered by TH116 triode valves. The TH116 anode supply capacitor banks have until recently been supplied by conventional 6-pulse silicon controlled rectifier (SCR) bridges delivering up to 40 kV at 5 A direct current. This dated system has become increasingly difficult to maintain. Early trials of an upgraded system using modern, compact, capacitor charging, switch mode supplies (SMPSs) resulted in severe supply power quality issues due to the pulsed nature of the current demanded from the capacitor banks. Measurements and Spice simulations of the old and replacement supplies allowed the power quality issues to be investigated and an additional external-to-the-SMPS regulator control loop to be developed. The new SMPSs operating with the additional control loop have been tested successfully on several of the linear accelerator stages and are now in continuous operational use. The process of replacing all the original SCR 6-pulse bridges is now well advanced and the operational benefits for ISIS are becoming evident.
THPPD078	Cold Cathode Thyratron Based High-voltage Kicker Generators at the Duke Accelerators: Six Year Experience	3698
	V. Popov, S.F. Mikhailov, P.W. Wallace, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DOE grant #DE-FG02-97ER41033. The performance of the Duke storage ring based light sources, the Duke storage ring FEL and High Intensity Gamma-ray Source (HIGS), has been greatly improved since 2007 as the result of operating a new full-energy, top-off booster injector (0.18 - 1.2 GeV), allowing fixed energy operation of the storage ring (0.25 - 1.2 GeV). The injection/extraction kicker system is one of the key components of the accelerator facility which determines efficiency and reliability of the light source operation. Pseudo-Spark Switches(PSS), also known as cold cathode thyratrons, are the critical components of the high voltage pulse generators for kickers. More than six years of operation has allowed us to study the lifetime issue for the 10 kA class devices. Recently, we have tested the next generation cold cathode thyratron, with one installed in one of our storage ring kicker high voltage generators. In the present paper we will also present preliminary test results of this new thyratron and the required modifications of its triggering driver to improve its performance.
THPPD079	Compact, High Current, High Voltage Solid State Switches for Accelerator Applications	3701
	H.D. Sanders, S.C. Glidden APP, Freeville, USA
	Most switches used for high current, high voltage accelerator applications are vacuum or gas switches, such as spark gaps and thyratrons. Recently, high voltage IGBT based switches have become common, but are limited in current and are not compact. This paper will describe a compact, high current, high voltage solid state switch. These switches have been tested to 50kV, to greater than 12kA, to greater than 50kA/μs, to 360Hz, and to 3x108 pulses, without failure. They have been used in accelerators to drive klystrons and kickers, and have been used as crowbars while offering advantages over thyratron switches for cost, lifetime, size and weight. The switches are based on series connected fast thyristors with 3cm2 die in a 20cm2 package. This package is more compact than TO-200 Puk sized devices, and does not require compression for proper operation. Each package is rated for 4kV, 14kA and 30kA/μs. One example, a 48kV switch which includes the trigger and snubber circuits, fits in a volume of 200mm x 85mm x 65mm, and requires only a fiber-optic trigger input. Such switches have been used on SRS and EMMA at Daresbury Laboratory in the UK, and at several US national laboratories.
THPPD081	Droop Compensation for the High Voltage Converter Modulators at the Spallation Neutron Source	3704
	G. Patel, D.E. Anderson, D.J. Solley, M. Wezensky ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725 The Spallation Neutron Source (SNS) has been in operation since 2006 and has demonstrated up to 1 MW of beam power. At 1MW, the High Voltage Converter Modulators (HVCMs) are delivering 11MW pulsed power to the Klystrons for 1185us at 60 Hz. The pulsed output of the modulator has a substantial voltage droop. The future operational goals of the accelerator involve delivering 1.4 MW to the target. This implies an increase in the output pulse width of the HVCM, resulting in loss of RF control from inadequate control margin for LLRF systems due to modulator voltage reduction at the end of pulse. Initially, the HVCM was designed with a pulse width modulation scheme for droop compensation but early operations revealed this technique unreliable for full power operation. Increasing the output voltage of the modulator would likely compromise system reliability. This paper proposes the use of alternate modulation schemes to address the voltage droop. The effect of frequency modulation and phase shift modulation on output pulse is studied and concludes by selecting an optimum modulation algorithm to be implemented. Experimental results will also be presented.
THPPD082	A Novel Solid-State Marx Modulator Topology with Voltage Droop Self-Compensation	3707
	P. Chen, M. Lundquist, D. Yu DULY Research Inc., Rancho Palos Verdes, California, USA
	Funding: Work supported by U.S. Department of Energy SBIR grant no. DE-FG02-08ER85052. Solid-state Marx modulators are preferred over conventional modulators in accelerators and radar applications because of their high flexibility, high reliability and long life. However, voltage droop is a notable issue. A novel topology of solid-state Marx modulators is described in this paper for raising their electric energy utilization ratios (EEURs). The new Marx modulator incorporates a buck regulator circuit into each Marx cell and adopts a higher charge voltage than that of application. The topology allows Marx cells to store more electric energy and utilize the energy more efficiently than others. Initial theoretical analysis and preliminary experiments show that solid-state Marx modulators constructed with this topology and under proper control of the stepwise energy release are able to significantly enhance their EEURs. The cost effective Marx modulators with compact energy storage sizes will resolve the issue of voltage droop when they are used in high power, long pulse applications.
THPPD083	Analysis of Kicker Noise Induced Beam Emittance Growth	3710
	W. Zhang, L. A. Ahrens, I. Blackler, M. Blaskiewicz, J.M. Brennan, W. Fischer, H. Hahn, H. Huang, N.A. Kling, M. Lafky, G.J. Marr, K. Mernick, J.-L. Mi, M.G. Minty, C. Naylor, T. Roser, J. Sandberg, T.C. Shrey, B. Van Kuik, A. Zelenski BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Over the last few years, physicists have suspected the presence of noise acting on the RHIC beams observable as occasional emittance growth at high beam energies. While the noise was sporadic in the past, it became more persistent during the run-11 setup period. An investigation diagnosed the source as originating from the RHIC abort kicker system. Once identified the issue was quickly resolved. We report in this paper the investigation result, circuit analysis, measured and simulated waveforms, solutions, and future plans.
THPPD084	Analysis of Beam Loss Induced Abort Kicker Instability	3713
	W. Zhang, L. A. Ahrens, W. Fischer, H. Hahn, J.-L. Mi, C. Pai, J. Sandberg, Y. Tan BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.
THPPD085	Research and Development of RHIC Injection Kicker Upgrade with Nano Second FID Pulse Generator	3716
	W. Zhang, W. Fischer, H. Hahn, C.J. Liaw, C. Pai, J. Sandberg, J.E. Tuozzolo BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled result. This is the very first attempt to drive a high strength fast kicker magnet with a nanosecond high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.