07 Accelerator Technology
T30 Subsystems, Technology and Components, Other

Paper	Title	Page
TUPC166	Accelerator R&D in the QUASAR Group	1425
	C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by STFC, the EU under GA-PITN-215080, the Helmholtz Associations and GSI under VH-NG-328. Since its start in 2007, the QUASAR Group’s research activities have grown considerably: Whilst the research program towards an ultra-low energy storage ring (USR) at the future facility for low-energy antiproton and ion research (FLAIR) is still the main research focus, developments of beam diagnostics tools for accelerators and lights sources, investigations into superconducting linear accelerators and medical applications, including the potential use of antiproton beams for cancer therapy purposes, widen the Group’s activities and international collaboration considerably. An overview of the QUASAR Group’s research achievements in accelerator science and technology to date is given in this contribution.
TUPS052	An FPGA Based Controller for the MICE Target	1647
	P.J. Smith, C.N. Booth, P. Hodgson, E. Overton, M. Robinson Sheffield University, Sheffield, United Kingdom J. Leaver, K.R. Long Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: UK Science and Technology Facilities Council The MICE experiment uses a beam of low energy muons to test the feasibility of ionization cooling. This beam is derived parasitically from the ISIS accelerator at the Rutherford Appleton Laboratory. A target mechanism has been developed that rapidly inserts a small titanium target into the circulating proton beam immediately prior to extraction without unduly disturbing the primary ISIS beam. The original control electronics for the MICE target was based upon an 8-bit PIC. Although this system was fully functional it did not provide the necessary IO to permit full integration of the target electronics onto the MICE EPICS system. A three phase program was established to migrate both the target control and DAQ electronics from the original prototype onto a fully integrated FPGA system that is capable of interfacing with EPICS through a local PC. This paper discusses this upgrade program, the motivation behind it and the performance of the upgraded target controller.
TUPS056	Synchronizing GEANT and 3D CAD - A Collaborative Engineering Study at ILD	1659
	L. Hagge, S. Eucker, B. List, S. Sühl, N. Welle DESY, Hamburg, Germany
	The design of a detector for a high-energy physics experiment is a complex task, driven by two different communities: The scientists aim to optimize the detector performance, while engineers are tasked to provide a design that can actually be built. Both groups have their own specific tools (e.g. GEANT versus 3D CAD systems) that are employed to model the detector and improve its design. The ensuing models need to be compared and synchronized at regular intervals, so that optimizations made to the physics simulation model are propagated to the engineering world, and engineering solutions are reflected properly in the physics simulation. Based on experience from the European XFEL project, DESY is providing tools and processes for establishing this synchronization at a very early stage in the design of the International Large Detector (ILD) for the International Linear Collider (ILC). They have been used to analyze compliance and differences of the ILD engineering design and physics simulation models. The poster introduces tools and process and presents first results and lessons learned.
TUPS066	Design of Front End Safety Interlock System for Taiwan Photon Source	1689
	H.Y. Yan, J.-R. Chen, G.-Y. Hsiung, C.K. Kuan, I.C. Sheng, Z.-D. Tsai NSRRC, Hsinchu, Taiwan
	Safety interlock is one of critical subsystems in synchrotron radiation accelerator. A front end (FE) interlock prototype system has been designed, fabricated, and initially tested for Taiwan Photon Source (TPS). TPS FE interlock logic is designed based on that of Taiwan Light Source (TLS), and moderately modified due to the accelerator parameter discrepancy between TPS and TLS. The programmable automation controllers (PAC) have been utilized in FE safety interlock system for their reliability, convenience, processing capability, communication, and stability in user interface. In FE PAC system, touch panels are used as the graphical user interface (GUI) to control and monitor FE components. In addition, with GUI control it is used to beam position monitoring devices as well as confined beam sizes aperture for beam line users. The interlock design such as data acquisition and parameters monitoring for vacuum pressure, flow rate of cooling water, pressure of compressive air, chamber and water temperature, and overall interlock logic are also presented in this paper.
TUPS067	Photon-stimulated Desorption Experiment for a TPS Crotch Absorber	1692
	Y.T. Cheng, G.-Y. Hsiung, C.K. Kuan, A. Sheng, H.Y. Yan NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC) is constructing a large third-generation synchrotron accelerator in Taiwan, the so-called Taiwan Photon Source (TPS). This 3-GeV, 500-mA machine will generate high-density bending-magnet radiation, of which 90 % of the power is absorbed by the crotch absorber in the storage ring. To understand better the beam-cleaning and photon-desorption phenomena of a copper crotch absorber, we have performed a PSD (photon-stimulated desorption) test in Taiwan Light Source (TLS) at Beam line 19 (BL19). Some mathematical modelling, experimental designs and results are also presented here.
TUPS075	Experimental determination of impedance and delay time of the 100 Ω meander transmission line for the SPIRAL2 Single Bunch Selector	1710
	M. Di Giacomo GANIL, Caen, France P. Balleyguier CEA/DAM/DPTA/SP2A, Bruyères-le-Châtel, France A.C. Caruso, F. Consoli INFN/LNS, Catania, Italy A. Longhitano ALTEK, San Gregorio (CATANIA), Italy
	The Spiral2 driver requires a Single Bunch Selector to reduce the bunch repetition rate at the experimental targets. A 100 Ω meander line is used in the beta 0.04 medium energy line of the Spiral2 driver. The non standard characteristic impedance figure helps to reduce the pulsed power but introduces the problem of calibrated measurements. The paper describes the results of the different methods used to measure the impedance and the delay of the electrodes.
TUPS076	The Specification Process for the Large Scale Accelerator Project FAIR	1713
	U. Weinrich GSI, Darmstadt, Germany
	The project FAIR is a large scale international accelerator facility with a high complexity within the accelerator complex. The project is owned by the recently founded FAIR GmbH while the physical-technical layout of the accelerator part of the facility is under the responsibility of GSI. This is the so-called two company model. Most of the accelerator subsystems and components are foreseen to be delivered In-Kind by accelerator institutes from Europe and Asia. In addition direct procurement is foreseen for those components not covered by in-kind-contributions or being very critical in time. Furthermore procurement has already started of components covered by special agreements and funding.
TUPS077	Shaping of Ion Pulses from an Electron Beam Ion Source for Particle Injection into Accelerators	1716
	F. Ullmann, A. Schwan DREEBIT GmbH, Dresden, Germany U. Hagen, O. Heid, H. von Jagwitz Siemens AG, Healthcare Technology and Concepts, Erlangen, Germany G. Zschornack Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
	Electron Beam Ion Sources (EBISs) provide highly charged ions for many applications, amongst others for particle injection into accelerators. Although EBISs are limited in ion output they feature a lot of advantages which qualify them for accelerator injection. The ion pulses extracted from the ion sources can be directly injected into an accelerator sequence which however requires ion pulses with distinct shape and length. We present the production of ion pulses matching the requirements of particle injection. The ions are produced by trapping in a high density electron beam for a certain time with electrostatic potentials providing for their axial trapping. The ions are extracted by lowering the trapping potential, i.e. opening the trap. Due to the ion energy distribution within the trapping region ion extraction can be controlled by controlling the trapping potential. A specific time dependent control mode of the trapping potential thus allows to produce ion pulses with designated shape and length. Source parameters such as working gas pressure, electron beam current and energy are influencing the energy distribution of the ions which in turn is influencing pulse shaping.
TUPS078	Electron Beam Ion Sources – A New Access for Particle Acceleration	1719
	F. Ullmann, F. Grossmann, V.P. Ovsyannikov, A. Schwan DREEBIT GmbH, Dresden, Germany G. Zschornack Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
	Electron Beam Ion Sources (EBISs) produce highly charged ions in a high density electron beam. Due to their operational principle EBISs have a lot of advantages although limited in ion output. Since the radial source region is given by a narrow electron beam the extracted ion beam features a very low transversal emittance. Moreover, the ions are ionized by a monoenergetic electron beam resulting in a small variation of the ion energy distribution, and thus in a very low longitudinal emittance. Together with a low basis pressure of less than 10-9 mbar this result in a high quality ion beam. The ions can be extracted as continuous beam as well as ion pulses with distinct pulse shapes. Providing almost any element with any charge state of up to completely ionized ions gives a large number of different projectiles and kinetic energies. The use of EBISs whether based on permanent magnets or on cryogen-free superconducting magnets has been proven in a variety of fields and applications. In addition, their compact design makes them transportable, low in operational costs, and guarantee easy handling.
TUPS079	Construction of a Novel Compact High Voltage Electrostatic Accelerator	1722
	P. Beasley, O. Heid Siemens AG, Healthcare Technology and Concepts, Erlangen, Germany
	A compact demonstrator system based on a Cockcroft-Walton (or Greinacher) cascade has been successfully built and tested. The concept has been developed using modern materials and a different design philosophy, which in turn can then enable this novel configuration to operate at much higher voltage gradients. This paper explores the progress made over the past 18 months and future plans to utilise the technology to develop one such concept for an energy efficient 10MV, 100μA, tandem proton accelerator, with a <2m2 footprint. The development of such a compact high voltage particle accelerator, with high current capability has the potential to access a wide range of commercial opportunities outside the laboratory.
TUPS080	Low Energy Bunching with a Double Gap RF Buncher	1725
	H. von Jagwitz, U. Hagen, O. Heid, S. Setzer Siemens AG, Erlangen, Germany
	A compact double gap bunching system for low energy proton beams is presented. The system is designed for the bunching of a low current proton beam (less than 50μA) with an energy of 10 keV. The buncher operates at 150 MHz and bunches without significantly changing the beam energy. The beam is generated by an Electron Beam Ion Source and has to be bunched for the subsequent acceleration in a 150 MHz linear accelerator. The buncher contains two short gaps and an RF electrode inbetween. Thus the full length of the buncher in the beamline is in the range of 2 cm. The location of the bunch focus depends on the buncher power. The bunched beam was analysed at a distance of 550 mm with a fast faraday cup. The bunching effectivity was determined as 50%, which means that 50% of the protons of the beam were located in bunches with a width of 60°, which is a reasonable value of acceptance for a conventional accelerator cavity. Some theory and detailed results will be presented.
TUPS081	3D Visualization, Simulation and Virtual Reality in Accelerator Development	1728
	L. Hagge, A. Herz, J. Kreutzkamp, S. Lang, V. Rupprecht, S. Sühl, N. Welle DESY, Hamburg, Germany
	Visualizing complex beamline designs, animating installation procedures and virtually walking through planned facilities - 3D modelling is a powerful tool with a broad range of applications in accelerator development. The poster describes established and emerging 3D modelling applications at the European XFEL and their benefits: 3D visualization enables inspection and compliance analysis of interfacing systems and components. Simulations enable early verification of e.g. safety and transportation concepts. Digital humans can be inserted into accelerator models to perform e.g. reachability and field-of-sight studies for installation works. Movies of transport and installation procedures can be created for staff training. And ultimately, stereo projection can be used to inspect and simulate designs and processes in virtual environments. 3D modelling helps discovering and resolving design issues earlier and leads to large savings in time and cost.
TUPS082	The LEBT Chopper for the Spiral 2 Project	1731
	A.C. Caruso, F. Consoli, G. Gallo, D. Rifuggiato, E. Zappalà INFN/LNS, Catania, Italy M. Di Giacomo GANIL, Caen, France A. Longhitano ALTEK, San Gregorio (CATANIA), Italy
	The Spiral 2 driver uses a slow chopper situated in the common section of the low energy beam transport line to change the beam intensity, to cut off the beam in case of critical loss and to avoid hitting the wheel structure of rotating targets. The device has to work up to 10 kV, 1 kHz repetition frequency rate and its design is based on standard power circuits, custom alarm board and vacuum feed-through. The paper summarizes the design principles and describes the test results of the final device which has been installed on the beam line test bench.
TUPS084	Development Status of PPS, MPS and TS for IFMIF/EVEDA Prototype Accelerator	1734
	H. Takahashi, T. Kojima, T. Narita, K. Nishiyama, H. Sakaki, K. Tsutsumi JAEA, Aomori, Japan
	Control System for IFMIF/EVEDA* prototype accelerator consists of six subsystems; Central Control System (CCS), Local Area Network (LAN), Personnel Protection System (PPS), Machine Protection System (MPS), Timing System (TS) and Local Control System (LCS). The IFMIF/EVEDA prototype accelerator provides deuteron beam with the power more than 1 MW, which is as same as that in cases of J-PARC and SNS. Then, the PPS is required to protect technical and engineering staff against unnecessary exposure and the other danger phenomena. The MPS and the TS are strongly required a high performance and precision to avoid radio-activation of the accelerator components. To realize these requirements, the PPS designed that Programmable Logic Controllers (PLCs) are used mainly, and a sequence is programmed for entering and leaving of controlled area and etc. Hardware and logic sequences for the MPS are designed to realize the beam inhibition time within 30 micro-seconds. The TS prototype modules were designed and tested using 10 MHz master clock and 100 Hz reference trigger. This article presents the PPS, MPS and TS design in details. * International Fusion Material Irradiation Facility / Engineering Validation and Engineering Design Activity
TUPS085	Mass Production Report of C-band Choke Mode Accelerating Structure and RF Pulse Compressor	1737
	S. Miura, T. Hashirano, F. Inoue, K. Okihira MHI, Hiroshima, Japan T. Inagaki RIKEN/SPring-8, Hyogo, Japan H. Maesaka, T. Shintake RIKEN Spring-8 Harima, Hyogo, Japan
	RIKEN and JASRI already completed the construction of XFEL/SPring8. Recently the facility was named “SACLA” (SPring-8 Angstrom Compact Free Electron LAser). The commissioning team succeeded in acceleration of 8 GeV electron beam and observation of the undulator light of 0.8 angstrom wavelength in March 2011. Now the accelerator is stably operated for the XFEL commissioning. In this project, a C-band (5712 MHz) choke mode accelerating structures and C-band RF pulse compressors are employed to obtain a high acceleration gradient of more than 35 MeV/m. We completed the fabrication of 128 accelerating structures, 64 RF pulse compressors, and 64 units of waveguide components and conducted RF measurements on them until May 2010. We report the result of the mass-production of these 64 C-Band units.
TUPS086	Ultra-high Resolution Observation Device for Carbon Stripper Foil	1740
	Y. Takeda, Y. Irie, I. Sugai KEK, Ibaraki, Japan
	To observe a growth process of a pinhole on a HBC-foil due to beam irradiation, an up to 10 um of device for ultra-high resolution observation is needed. For the environment where we use the device for observation is so severe as under high radiation and in vacuum, there is no device available for long-time observation. Then, we designed and created a wholly new method based system which enables constant observation by ultra-high resolution even under high radiation environment. We attempted several experiments, compared materials usable under radiation environment, checked up various optical systems which enables high resolution, and finally developed the best method. As a result, we successfully invented an ultra-high resolution observation device available for monitoring an object about 8 meters distant by 8.3um resolution.
TUPS087	Development of Permanent Magnet Focusing for Klystrons	1743
	Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, T. Matsumoto, S. Michizono, M. Yoshida KEK, Ibaraki, Japan
	Funding: KEK Applying permanent magnet technology to beam focusing in klystrons can reduce their power consumption and reliability. These features benefit variety of applications especially for large facilities that use number of klystrons such as ILC. A half scaled model will be available in summer and full model should be available in September. Research and Development status will be reported.
TUPS088	Charge Stripping of Uranium-238 Ion Beam with Low-Z Gas Stripper	1746
	H. Imao RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan N. Fukunishi, A. Goto, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, H. Okuno, T. Watanabe, Y. Yano, S. Yokouchi RIKEN Nishina Center, Wako, Japan
	One of the primary goals of the RIKEN RI beam factory is to generate unprecedented high-power uranium beams (up to tens kW), which yield an enormous breakthrough for exploring new domains of the nuclear chart. The development of reliable and efficient charge stripping scheme for such high-power beams is a key unsolved issue, affecting the overall performance of the heavy ion accelerations. A charge stripper using low-Z (low atomic number Z) gas is an important candidate. Because of the suppression of the electron capture process, the high equilibrium mean charge states for the low-Z gas stripper are expected in conjunction with the intrinsic robustness of the gas. There was, however, no direct experimental data of the charge evolution, because of the difficulty in making massive windowless low-Z gas targets. In the present work, the charge evolution of the 238U beams injected at 10.75 MeV/u were investigated using thick hydrogen and helium gas strippers with huge differential pumping system newly developed. In the energy region of interest, near 10 MeV/u, achievable mean charge states around 65+ with the low-Z gas strippers are far superior to those of the medium-Z ones around 55+.
TUPS089	HI-13 Tandem Accelerator Radiation Protection System	1749
	X.F. Wang, Y.M. Hu CIAE, Beijing, People's Republic of China
	In HI-13 Tandem Accelerator laboratory, a new radiation protection system has been built Which composed of 7 protective door control units and 7 emergency alarms , 23 groups of indicators,17 groups of workshop-empty units , L.E and IMAG Faraday cups as well as computer control and display system . Pre-empty process is prerequisite before close the protective doors to ensure nobody be exposed on irradiation environment otherwise the door-open would be disabled. Even thought somebody left, pushing nearby alarm button and emergency door-open button will induce glittery signal and simultaneous door-openning. L.E and IMAG Faraday cups execute immediate beam interruption once accidence occured . The distributed indicators indicate real time status of all the work fields. All above devices and units are interlocked follow some complex but logical protective rules. Computer workstation is built and accordingly, after full information and operation action signals are collected and transferred, the software can complete full-sides status monitoring, provide convenient control and display interfaces as well as pop adequate prompt frames.
TUPS090	Operation Status of SECRAL at IMP	1750
	W. Lu, Y. Cao Graduate School of the Chinese Academy of Sciences, Beijing, People's Republic of China Y.C. Feng, X.H. Guo, W. Lu, L.T. Sun, D. Xie, X.Z. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) is a fully superconducting ECR ion source built in 2005 with an innovative solenoid-inside-sextupole structure. Since then it has delivered many highly-charged ion beams for HIRFL (Heavy Ion Research Facility in Lanzhou) at IMP (Institute of Modern Physics), such as Xe27+，Kr19+，Bi36+ and Ni19+, and its on-line operating time increases year by year. By January 2011, the operation time of SECRAL has totaled up to 5700 hours. The increasing demand for intensive highly-charged ion beams has lead to the continuous enhancement of the SECRAL. To meet the requirement for stable highly-charged metallic ion beams, double-frequency of 18 GHz + 24 GHz heating with an off-axis oven had been carried out in 2010. 60-80 euA of Bi36+ were produced at microwave power of about 2 kW and had been delivered continuously to HIRFL for about 10 days without any breakdowns. A number of improvements were planned to further improve the long-term stability of metallic ion beams.
TUPS092	Research of Thermal Deformation on a Compact Cyclotron CYCHU-10	1753
	K.F. Liu HUST, Wuhan, People's Republic of China
	Nowadays, a cyclotron CYCHU-10 used for PET is under construction in Huazhong University of Science and Technology (HUST) due to the growing demands in medical applications. For space-saving and low energy consumption, the CYCHU-10 was designed compactly and accurately, especially for the RF cavity consists of the valley of the magnetic pole and the dee electrodes installed on the vacuum chamber. The RF system will supply a 10kw power and large part of it will transform into thermal energy. This paper will introduce the thermal deformation of the RF cavity and the main vacuum chamber. Meanwhile the finite elements analysis thermal deformation with ANSYS Products will be present. Finally, the cooling system for the RF cavity will be carefully designed due to the result of thermo analysis and the mechanical tolerance demand in the RF system. Keywords- thermal deformation; mechanical tolerance; FEA;RF power.
TUPS093	Automatic Measurement System for Electrical Verification of the LHC Superconducting Circuits	1756
	A. Kotarba, M. Bednarek, P. Jurkiewicz, J. Ludwin, M. Talach IFJ-PAN, Kraków, Poland R. Mompo CERN, Geneva, Switzerland
	In the LHC machine, superconducting magnet circuits are used on a very large scale. The circuits, more than 1600, are all equipped with a complex set of instrumentation required for safe operation and diagnostics. The length of many circuits exceed 3 km. Due to risks of accidental damages during transport and assembly or misconnection of the circuits’ auxiliary components, it is necessary to perform an Electrical Quality Assurance (ELQA) campaign after every major intervention on a circuit and also after each thermal cycle of the machine. In order to be able to perform reliable tests on a circuit within a short time frame, a highly extensible automated mobile test system was designed and built. Four of these instruments were successfully used during the Hardware Commissioning phases of the LHC. This paper describes the hardware solutions used in the test system.
TUPS094	Girder and Support System for PLS-II Project	1759
	H.-G. Lee, H.S. Han, J.Y. Huang, Y.-G. Jung, D.E. Kim, S.N. Kim, S.H. Nam, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. We have designed a new steel magnet girder using new schemes to achieve long-term mechanical stability, vibration suppression and precision adjusting system. Each half cell of girder is composed of three pieces, two multipole magnet girder(MMG) and one dipole magnet girder(DMG). The storage ring girders consist of 48 multipole magnet girders and 24 dipole magnet girders. The new girder systems have been fabricated and tested. Recently the girders have been installing and testing the moving mechanism in the storage ring. In this report, the design consideration for the PLSII girder and support systems are reported.
TUPS096	ESS Parameter List Database and Web Interface Tools	1762
	K. Rathsman, S. Peggs, P. Reinerfelt, G. Trahern ESS, Lund, Sweden J. Bobnar Cosylab, Ljubljana, Slovenia
	The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon the world's most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac delivers 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The Accelerator Design Update (ADU) collaboration of mainly European institutions will deliver a Technical Design Report at the end of 2012. To ensure consistency of the information being used amongst all subgroups throughout the period of accelerator design and construction, a parameter list database and web interface have been proposed. The main objective is to provide tools to identify inconsistencies among parameters and to enforce groups as well as individuals to work towards the same solution. Another goal is to make the Parameter Lists a live and credible endeavor so that the data and supporting information shall be useful to a wider audience such as external reviewers as well as being easily accessible.
TUPS097	In-situ Experiments of Vacuum Discharge using Scanning Electron Microscopes	1765
	T. Muranaka, V.G. Ziemann Uppsala University, Uppsala, Sweden T. Blom, K. Leifer Uppsala University, Department of Engineering Sciences, Uppsala, Sweden
	Funding: This work is supported by the 7th European Framework Program EuCARD under grant number 227579 Fundamental understandings of vacuum discharge mechanisms and involving surface damage is an indispensable for CLIC feasibility study. We have been conducting dc experiments inside a Scanning Electron Microscope (SEM) at Uppsala university in order to investigate localised breakdown phenomena. By using a SEM, we achieve the resolution of the electron probe in the few-nm range, which is of great advantage as the surface roughness of the polished accelerating structures is in the same scale. The high accelerating field of 1 GV/m is realised by biasing an electrode with 1 kV set above the sample with a gap of sub μm. Furthermore, a second SEM equipped with a Focused Ion Beam (FIB) is used to modify the topography of sample surfaces thus the geometrical dependence of field emissions and vacuum discharges could be studied. The FIB can be used for the surface damage analysis as well. We have demonstrated subsurface damage observations by using FIB to sputter a rectangular recess into the sample in the breakdown region. Those powerful surface analysis techniques can be productively applied to the study of fatigue in prototype accelerating structures.
TUPS098	Machining and Characterizing X-band RF-structures for CLIC	1768
	S. Atieh, M. Aicheler, G. Arnau-Izquierdo, A. Cherif, L. Deparis, D. Glaude, L. Remandet, G. Riddone, M. Scheubel CERN, Geneva, Switzerland D. Gudkov, A. Samoshkin, A. Solodko JINR, Dubna, Moscow Region, Russia
	The Compact Linear Collider (CLIC) is currently under study at CERN as a potential multi-TeV e+e– collider. The manufacturing and assembling tolerances for making the required RF components are essential for CLIC to perform efficiently. Machining techniques are relevant to the construction of ultra-high-precision parts for the Accelerating Structures (AS). Optical-quality turning and ultra-precision milling using diamond tools are the main manufacturing techniques identified to produce ultra-high shape accuracy parts. A shape error of less than 5 micrometres and roughness of Ra 0.025 are achieved. Scanning Electron Microscopy (SEM) observation as well as sub-micron precision Coordinate Measuring Machines (CMM), roughness measurements and their crucial environment were implemented at CERN for quality assurance and further development. This paper focuses on the enhancements of precision machining and characterizing the fabrication of AS parts.
TUPS099	A Study of the Surface Quality of High Purity Copper after Heat Treatment	1771
	M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin CERN, Geneva, Switzerland
	The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.
TUPS100	Manufacturing the Linac4 PI-mode Structure Prototype at CERN	1774
	G. Favre, A. Cherif, A. Dallocchio, J.-M. Geisser, L. Gentini, F. Gerigk, S.J. Mathot, M. Polini, S. Sgobba, T. Tardy, R. Wegner CERN, Geneva, Switzerland
	The PI-Mode Structure (PIMS) of Linac4 consists of 7-cell cavities made from alternating OFE copper discs and rings welded together with electron beam (EB) welding. A full-scale prototype cavity of almost 1.5 m in length has been manufactured, assembled, and tested at CERN to prepare the series production of 12 PIMS cavities as part of an international collaboration. This paper reports on the construction experience including machining operations, EB welding, vacuum brazing, and metrological measurements results.
TUPS101	A Fast 650V Chopper Driver	1777
	M.M. Paoluzzi CERN, Geneva, Switzerland
	In the framework of Linac4 and the Superconducting Proton Linac (SPL) studies at CERN, the design for a beam chopper has been carried out. The chopper is basically a kicker that deviates part of the beam towards a dump. It is made of two 50 Ω, slow wave lines facing each other, matching the beam velocity and driven with a minimum of 500 V. Due to the bunch spacing of 2.84 ns, a system rise and fall time (3 %-90 %) below 2.5 ns is required with pulse lengths ranging from 8 ns to hundreds of μs. Although different solutions for the driver amplifier where devised in the past, none of the achievements was entirely satisfactory. This paper describes a new design and prototype that meets all the required specifications.
TUPS102	Design of an FPGA-based Radiation Tolerant Agent for WorldFIP Fieldbus	1780
	G. Penacoba Fernandez, P. Alvarez, E. Gousiou, S.T. Page, J.P. Palluel, J. Serrano, E. Van der Bij CERN, Geneva, Switzerland
	CERN makes extensive use of the WorldFIP field-bus interface in the LHC and other accelerators in the pre-injectors chain. Following the decision of the provider of the components to stop the developments in this field and foreseeing the potential problems in the subsequent support, CERN decided to purchase the design information of these components and in-source the future developments using this technology. The first in-house design concerns a replacement for the MicroFIP chip whose last version was manufactured in an IC feature size found to be more vulnerable to radiation of high energy particles than the previous versions. NanoFIP is a CERN design based on a Flash FPGA implementing a subset of the functionality allowed by the communication standard, fitting the requirements of the different users and including the robustness against radiation as a design constraint. The development presented involved several groups at CERN working together in the framework of the Open Hardware Repository collaboration, and aiming at maximizing the interoperability and reliability of the final product.
TUPS103	High Temperature Radio Frequency Loads	1783
	S. Federmann, F. Caspers, A. Grudiev, E. Montesinos, I. Syratchev CERN, Geneva, Switzerland
	In the context of energy saving and recovery requirements the design of reliable and robust RF power loads which permit a high outlet temperature and high pressure of the cooling water is desirable. Cooling water arriving at the outlet with 150 deg C and more than 20 bar has a certain value. Normal RF power loads containing dielectric and sensitive windows usually do not permit going much higher than 50 deg C. Here we present and discuss several design concepts for narrow-band “metal only” RF high power loads. One concept is the application of normal steel corrugated waveguides structures near cutoff .This concept could find practical use above several GHz. Another solution are resonant structures made of normal magnetic steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 MHz taking advantage the rather high losses of normal steel may also be used in coaxial line geometries with large dimensions.
TUPS104	A Two Stage Fast Beam Chopper for Next Generation High Power Proton Drivers	1786
	M.A. Clarke-Gayther STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) project at RAL will test a two stage fast beam chopper, designed to address the requirements of high power proton drivers for next generation spallation sources, neutrino factories, and radioactive waste transmutation plants. A description is given of the status of development of the proposed two stage beam chopper. The results of a recent study on the dimensional optimisation of the proposed slow-wave structures, together with details of an updated beam line configuration for the chopper components, will be presented.
TUPS105	Beam Brightness Booster with Self-Stabilization of Electron-Proton Instability	1789
	V.G. Dudnikov, C.M. Ankenbrandt Muons, Inc, Batavia, USA
	The brightness and intensity of a circulating proton beam now can be increased up to the space charge tune shift limit by means of charge exchange injection or by electron cooling but cannot be increased above this limit. Significantly higher brightness can be produced by means of charge exchange injection with space charge compensation*. The brightness of the space charge compensated beam is limited at low level by an electron-proton (e-p) instability. Fortunately, the e-p instability can be self-stabilized at a high beam density. The “cesiation effect” significantly increases negative ion emission from gas discharges, and surface-plasma sources for intense high brightness negative ion beam production have been developed. These developments make it possible to produce stable “superintense” circulating beams with intensity and brightness far above the space charge limit. A beam brightness booster (BBB) for significant increases of accumulated beam brightness is discussed. Superintense beam production can be simplified by developing a nonlinear nearly-integrable focusing system with broad betatron tune spread and a broadband feedback system for e-p instability suppression. * M. Reiser, “Theory and Design of Charged Particle Beam”, second edition, p. 565-570, Wiley-VCH, (2006).
TUPS106	Absorber Materials at Room and Cryogenic Temperatures*	1792
	F. Marhauser, T.S. Elliott, A.T. Wu JLAB, Newport News, Virginia, USA E.P. Chojnacki CLASSE, Ithaca, New York, USA E. Savrun Sienna Technologies Inc., Woodinville, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We recently reported on investigations of RF absorber materials at cryogenic temperatures conducted at Jefferson Laboratory (JLab). The work was initiated to find a replacement material for the 2 Kelvin low power waveguide Higher Order Mode (HOM) absorbers employed within the original cavity cryomodules of the Continuous Electron Beam Accelerator Facility (CEBAF). This effort eventually led to suitable candidates as reported in this paper. Furthermore, though constrained by small funds for labor and resources, we have analyzed a variety of lossy ceramic materials, several of which could be usable as HOM absorbers for both normal conducting and superconducting RF structures, e.g. as loads in cavity waveguides and beam tubes either at room or cryogenic temperatures and, depending on cooling measures, low to high operational power levels.
THYB01	Advanced Beam Manipulation Techniques at SPARC	2877
	A. Mostacci, D. Alesini, P. Antici, A. Bacci, M. Bellaveglia, R. Boni, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, B. Spataro, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy B. Marchetti INFN-Roma II, Roma, Italy M. Migliorati University of Rome "La Sapienza", Rome, Italy L. Palumbo Rome University La Sapienza, Roma, Italy V. Petrillo, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma), Italy
	SPARC in Frascati is a high brightness photo-injector used to drive Free Electron Laser experiments and explore advanced beam manipulation techniques. The R&D effort made for the optimization of the beam parameters will be presented here, together with the major experimental results achieved. In particular, we will focus on the generation of sub-picosecond, high brightness electron bunch trains via velocity bunching technique (the so called comb beam). Such bunch trains can be used to drive tunable and narrow band THz sources, FELs and plasma wake field accelerators.
	Slides THYB01 [20.772 MB]