Workshop on Special Compact and Low Consumption Magnet Design

30/7-018 - Kjell Johnsen Auditorium (CERN)

30/7-018 - Kjell Johnsen Auditorium


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We are pleased to announce a Workshop on “Compact and Low Consumption Magnet Design for Future Linear and Circular Colliders”, which will be organized at CERN, Geneva, from Wednesday 26 to Friday 28 November 2014.

The Workshop intends to bring together experts from Laboratories and Industry working on magnet design mainly focusing on the two aspects of consumption and compactness. A variety of magnet technologies will be considered in the scope of the Workshop, i.e.: - Normal conducting electromagnets - Permanent magnets - Hybrid (EM+PM) magnets - Super-ferric magnets - Pulsed magnets (reducing r.m.s. current and consumption, with a potential cost saving).

The Workshop is officially supported by EUCARD-2 WP3: Energy Efficiency (EnEfficient)

Attendance and Contributions: The workshop is by invitation only.

Proposals for Workshop presentations should be addressed to the Program Committee members.

  • Akira Yamamoto
  • Alexander Gabard
  • Alexander Kovalenko
  • Anna Mierau
  • Antony Newborough
  • Ben Shepherd
  • Bernward Krause
  • Brennan Goddard
  • Carmen Tenholt
  • Chris Bailey
  • Daniel Schoerling
  • David Richter
  • Davide Aguglia
  • Davide Castronovo
  • Davide Tommasini
  • Fabrice Marteau
  • Franz-Josef Börgermann
  • Frédérick Bordry
  • Fulvio Boattini
  • GAEL Le Bec
  • Gilles Le Godec
  • Hamlet Khodzhibagiyan
  • Helene Mainaud Durand
  • Jan Borburgh
  • Jan Lindenberg
  • Jean Francois Bouteille
  • Jean-Marc Cravero
  • Jean-Paul Burnet
  • Jim Clarke
  • Karsten Kahle
  • Konstantinos Papastergiou
  • Kurt Artoos
  • Lauren Rianna Ormesher
  • Luca Bottura
  • Marco Buzio
  • Martin Johansson
  • Maurizio Vretenar
  • Michele Modena
  • Mike Seidel
  • Mikko Karppinen
  • Miroslav Georgiev Atanasov
  • Neil Marks
  • Norbert Collomb
  • Olivier de Loriol
  • Patrick Ngotta
  • Pedro Fernandes Tavares
  • Peter-Jurgen Spiller
  • Philipp Gardlowski
  • Philippe Lebrun
  • Pierre Alexandre Thonet
  • Pierre Vedrine
  • Rachelle Decreuse-Michaud
  • Roberto Lopez
  • Serge Claudet
  • Serge Pittet
  • Stephan Russenschuck
  • Stéphane Sanfilippo
  • Thomas Zickler
  • Timothy Alexander Keppert
  • Tobias Goetsch
  • Vladimir Kashikhin
  • Yannis Papaphilippou
    • Introduction
      Convener: Michele Modena (CERN)
      • 1
        CERN Welcome
        Speaker: Frederick Bordry (CERN)
      • 2
        Introduction to EuCard2
        Speaker: Maurizio Vretenar (CERN)
      • 3
        Introduction to "EnEfficient' Work Package of EuCard2
        Speaker: Mike Seidel
    • 1st Session: Future Development Scenarios
      Convener: Mike Seidel
      • 4
        The outlook for electricity in Western Europe
        Speaker: Matthew Wittenstein (IEA)
      • 5
        Why are particle accelerators so inefficient?
        High-energy accelerators/colliders have developed into large machines consuming high electrical power up to the 100 MW range, thus making the energy bill a major component of their operating costs and eventually of their acceptability by society. With several new projects under study beyond the Large Hadron Collider (LHC), and projections of rising electricity prices by energy agencies, this trend is expected to grow into a critical issue for future machines. While a minimum power duty can be estimated from the beam parameters of both circular and linear accelerators/colliders, they all share low grid-to-beam efficiency entailing much higher power requirements from the electrical networks. We analyse the sources of energy dissipation, from the closest to the farthest from the beams, and discuss the power efficiency of some existing machines and future projects. This methodology also enables to identify possible paths for improvement.
        Speaker: Philippe Lebrun (CERN)
    • 10:30 AM
      Coffee Break
    • 2nd Session: Opportunities of Energy Saving in Accelerators - Part 1
      Convener: Peter-Jurgen Spiller (GSI)
      • 6
        CERN plans towards energy efficiency
        High energy accelerators are usually great energy consumers and could not escape from being concerned by energy efficiency aspects. After recalling the context, major actions towards energy efficiency will be presented, with plans for the future.
        Speaker: Serge Claudet (CERN)
      • 7
        Magnet Energy Recovery: a way towards more compact and efficient systems
        Magnet energy recovery on a cycle-by-cycle basis shows potential for great energy savings and improvement of the grid power quality. Reducing the magnet duty cycle allows more compact mechanical layout and greater efficiency. To achieve such a benefit a system integration study is essential before starting the parallel development of magnets and power conversion/energy recovery systems.
        Speaker: Konstantinos Papastergiou (CERN)
      • 8
        Saving opportunities in accelerator magnets
        An accelerator magnet is usually excited either by water cooled copper coils powered with an effective current density in the range of 3-6 A/mm2 or by using superconducting coils, depending on the required field amplitude. Exceptions are often due to technical reasons (special constraints, easier construction, more reliability). Up to now, only in rare cases (in particular in experimental magnets) the energy consumption is an important design factor. The situation is however rapidly evolving and many research institutes are either revising the existing installations or planning the new ones with special attention towards energy consumption. This talk will review several “saving opportunities” presently considered in this domain.
        Speaker: Davide Tommasini (CERN)
    • 12:30 PM
      Lunch Break
    • 2nd Session: Opportunities of Energy Saving in accelerators - Part 2
      Convener: Peter-Jurgen Spiller (GSI)
      • 9
        Power Converters design optimization: need for an integrated approach with the magnet design
        This talk presents the basics of the design of a power converter for DC and pulsed magnet. Particularly the impact of the magnet design (inductance, voltage and current adaptation given by the number of turns, etc.) on the converter design is illustrated. Compromises between efficiency, cost and technologies are presented. Finally, the need and benefits of an integrated approach which considers the magnet design variables is demonstrated via a simplified example.
        Speaker: Davide Aguglia (CERN)
      • 10
        Iron-dominated cycled SC magnets for energy efficiency
        Speaker: Luca Bottura (CERN)
      • 11
        In-vacuum magnet design and challenges
        Synchrotron light sources can extend their wavelength reach significantly by putting the undulator arrays into the beam vacuum system. The advantages are such than many light sources now utilise in-vacuum undulators when required. However, there are a number of extra physics and engineering challenges which have to be dealt with when putting magnets in-vacuum. In this talk I will explain the motivation, the additional challenges, and the realisation of in-vacuum undulators.
        Speaker: Jim Clarke (STFC)
    • 3:30 PM
      Coffee Break
    • 3rd Session: The saving prospects in European Labs, projects and machine upgrades - Part 1
      Convener: Jim Clarke (STFC)
      • 12
        The CEA-Saclay experience
        Speaker: Pierre Vedrine (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR))
      • 13
        Compact and low consumption magnet design - The DESY experience
        During the last ten years a variety of electromagnets has been ordered to upgrade the PETRA accelerator into a synchrotron light source, to build up a new branch at the FLASH accelerator facility and to install the new European XFEL. The talk will give an overview of the ingredients which are necessary for developing and manufacturing magnets. Two septum designs will be presented to discuss how electricity costs can be reduced without losing machine performance. Furthermore design studies of combined function magnets and a permanent magnet design that could replace a quadrupole electromagnet to save energy costs will be shown.
        Speaker: Bernward Krause (DESY)
      • 14
        Magnet designs for the ESRF-SR2
        Magnets for the ESRF storage ring upgrade (SR2) are being developed. The power consumption of the new ring should be lower than the present ESRF consumption, with much more magnets installed. On top of that, the new lattice must preserve the existing source points in the ID straight sections: longitudinal compactness is a strong constraint. Permanent magnet (PM) and electromagnet (EM) devices are being developed for this purpose. It is foreseen to install PM dipoles with longitudinal gradient. The other magnets will be normal conducting, with optimized power consumption and length. These technological choices have been driven by the magnet tuning ranges, the ESRF experience and the limited development time. For EM magnets, low power consumption goes against compactness. A compromise can be reach with longitudinally compact magnets with increased transverse dimensions. A brief review of the ESRF-SR2 magnet designs and an estimation of the energy saving (as compared to standard J=5 A/mm2 designs) will be presented.
        Speaker: Gael Le Bec (ESRF)
      • 15
        Energy management at GSI and FAIR strategy on energy management
        GSI Helmholtzzentrum für Schwerionenforschung GmbH operates a unique large-scale accelerator for heavy ions. In the coming years the new international accelerator facility FAIR, one of the largest research projects worldwide, will be built at GSI. In the final extension FAIR consists of several heavy ion accelerator rings, experiment storage rings with up to 1,100 meters in circumference, two linear accelerators and about 3.5 kilometers high energy beam transfer lines as well as several experiment caves. In the context of rising energy prices and the responsible use of resources, GSI has taken the task to develop concepts for efficient use of energy. Actual work includes the introduction of a broad collection and analysis of energy consumption data and the development of the high efficient data center “Green IT Cube” and technologies such as load based cooling of accelerator components. The final intention of this work is to provide a modern and efficient research facility at reasonable energy costs and sustainable use of energy.
        Speaker: Philipp Gardlowski (urn:Facebook)
      • 16
        Energy efficient beam transport by means of high current pulsed magnets
        In order to raise the focusing gradient in case of bunched beam lines, an alternative, iron free, pulsed quadrupole was designed. The transfer channels between synchrotrons as well as the final focusing for the production of secondary beams are possible applications. The construction of this quadrupole is about to be finished and thus it is almost ready to be tested. The quadrupole is running in a pulsed mode, which means an immense saving of energy by avoiding standby operation. Still the high gradients demand high currents. Hence a circuit had to be developed which is able to reclaim a significant amount of the pulsing energy for following shots. The basic design of the pulsed quadrupole is introduced also considering its differences according to common technologies. Furthermore the energy efficient circuit is explicated and the limits of adaptability are considered.
        Speaker: Carmen Tenholt (GSI)
    • 3rd Session: The saving prospects in European Labs, projects and machine upgrades - Part 2
      Convener: Jim Clarke (STFC)
      • 17
        The PSI experience: A theory of evolution
        From the beginning, operating costs have been a factor in the design of accelerators and beamlines at PSI. However, limited funds and increasing power costs have made this aspect even more important nowadays. Through the history of PSI, we will present the initial prerogatives for magnet design at our institute and their evolution over time, resulting in the current compact design of the magnets for the SwissFEL project and the first design concepts for the SLS 2.0 upgrade.
        Speaker: Alexander Gabard (PSI)
      • 18
        CERN experience on PM based magnet design and procurement
        Speaker: Pierre Alexandre Thonet (CERN)
    • 10:00 AM
      Coffee Break
    • 4th Session: Efficient and compact magnet design examples - Part 1
      Convener: Daniel Schoerling (CERN)
      • 19
        Compact superconducting magnets for linear accelerators
        New Linear Accelerators based on SCRF cavities need compact and efficient superconducting magnet packages to focus and steer electron or proton beams. These magnets should be combined with SCRF cryomodules and installed inside or between them. A recent activity in this area was directed by FNAL-KEK collaboration to splittable conduction cooled magnets. Several magnet prototypes were built and successfully tested. These magnets were designed for high energy beams used in ILC, and Project-X. Nevertheless, there is an interest to explore splittable conduction cooled magnets for new accelerators: FNAL ASTA and PIP-II, KEK STF, SLAC LCLS II. Presented results of various magnets design, fabrication, and tests. Most magnet packages combine the quadrupole magnet and two dipole correctors. The presented magnetic measurement results confirm the specified magnet package parameters.
        Speaker: Vladimir KASHIKHIN (Fermilab)
      • 20
        Electromagnetic and hybrid design experience for CLIC magnet R&D
        Since 2009 CERN started R&D activities in order to identified and investigate the most challenging cases among the magnets needed for CLIC the Compact Linear Collider one of the possible Future Linear Colliders. In some specific cases the work is mainly done by our colleagues of STFC-Daresbury Lab (UK) part of the CLIC International Collaboration. In the last four years several theoretical studies, models and prototypes were realized mainly focusing two sub-system of the CLIC complex: the “2-beam Modules”, the modular elements that are composing the backbone of the two linacs of CLIC, and the Machine Detector Interface (MDI) that include the final focus elements as QD0 and SD0 and the antisolenoid. In this talk we revise the status of the studied and procured magnets. Among them the Drive Beam Quadrupoles, the Main Beam Quadrupoles, the main beam Steering Correctors all challenging for the required compactness, performances and production size, and the final quadrupole QD0 and the sextupole SD0, challenging for the high performances required in terms of gradients and stability.
        Speaker: Michele Modena (CERN)
      • 21
        ZEPTO: Tunable permanent magnet dipoles and quadrupoles
        Within the framework of the CLIC-UK collaboration between CERN and STFC, two types of permanent magnet based quadrupoles have been developed and built. These magnets have a very large tuning range (15-60 T/m and 4-43 T/m respectively). The parameters were specified for the challenging requirements of the CLIC Drive Beam Decelerator. Two prototypes have been built and successfully tested, demonstrating the tuning range, stability and field quality of these magnets. A study is also under way to develop a PM-based dipole with a tuning range of 0.8-1.6T, in line with requirements for the CLIC Drive Beam Turnaround Loop.
        Speaker: Ben Shepherd (STFC)
      • 22
        The experience at FERMILAB: recycler ring and beam lines based on PM technology
        Various permanent magnets were built and successfully operated at FERMILAB Accelerator Complex. The Recycler Ring and 8 Gev beam transfer line includes nearby 500 permanent magnet gradient dipoles and quadrupoles based on strontium ferrite bricks. For NLC were built and tested 6 adjustable permanent magnet quadrupoles with gradients up to 100 T/m, and wide range of integrated gradient changes. The NOVA beamline and the Main Injector ionization profile monitor permanent magnets were recently commissioned. They based on SmCo5 permanent magnets. In the presentation briefly discussed the FERMILAB experience in the area of permanent magnets design, fabrication, and operation.
        Speaker: Vladimir KASHIKHIN (Fermilab)
    • 12:30 PM
      Lunch Break
    • 4th Session: Efficient and compact magnet design examples - Part 2
      Convener: Daniel Schoerling (CERN)
      • 23
        Development and operation of a superconducting combined-function magnet system for J-PARC neutrino beam line
        Speakers: Akira Yamamoto (High Energy Accelerator Research Organization (JP)) , Toru Ogitsu (KEK)
      • 24
        Integrated magnet block design and production for MAX IV
        The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous 3rd gen. light sources with a compact integrated design having several consecutive magnet elements precision-machined out of a common solid iron block. This presentation consists of a brief description of the design, and mechanical + magnetic field measurement results from the magnet production series.
        Speaker: Martin Johansson (MaxLab)
    • 5th Session: Industrial perspective
      Convener: Gael Le Bec (ESRF)
      • 25
        Permanent (and soft) magnet materials for use in accelerators
        Permanent magnets and soft magnetic materials with specific properties have been frequently used in various assemblies at accelerators and colliders. Among these are undulators, wigglers as well as dipoles (PM based and specific electromagnets), PM-quadrupoles and higher multipoles. From energy consumption aspects, the PM-solutions may provide a contribution to long term energy savings combined with high long term stability. New PM-materials with enhanced properties at cryogenic temperatures may open new aspects for devices at low temperatures. Actual improvements in the properties of soft magnetic materials will contribute to more effective flux guidance elements. We will present some of the recent developments in these material classes which contribute to further enhancements of such units in future accelerator and collider projects.
        Speaker: Franz-Josef Börgermann (Vacuumschmelze GmbH & Co KG)
      • 26
        Development of electrical steel for highest efficiency applications
        Voestalpine is a producer of highest quality electrical steel. In recent years voestalpine proofed to be a reliable partner regarding the supply of electrical steel for the construction of magnets. From the point of the electrical steel producer the requirements of the magnet construction industry are very demanding. This contribution tries to show the difficulties that arise by the example of the MedAustron project. With the startup of the new continuous annealing line 2 voestalpine is now able to supply electrical steel for applications that require the highest efficiency available on the market. In this presentation an overview of the technical capabilities of the production of electrical steel is given. Possibilities to produce electrical steel with tailored properties concerning the coercitivity and the permeability are discussed. At the same time the physical limitations of electrical steel are discussed. Also the newest developments regarding electrical steel for higher frequency applications are discussed.
        Speaker: Tim Keppert (VoestAlpine)
      • 27
        Industrial challenges of compact magnet production
        The CLIC-UK collaboration between CERN and STFC produced two prototypes of permanent magnet based quadrupoles to cover the large tuning range (15 - 60 T/m and 4 - 43 T/m respectively) required for the CLIC Drive Beam Decelerator. The space envelope and accuracies to achieve the demanding parameter challenges have been addressed during the production of the prototypes. Assembly sequencing, accuracy analysis and an investigation into industrial capabilities in both metrology and manufacture/assembly led to a proposal in the efficient and specification meeting “mass-production”. Manufacture and assembly of the prototypes provided the identification and foundation of techniques and methodologies essential for large scale industrial manufacture.
        Speaker: Norbert Collomb (STFC Daresbury Laboratory)
    • 4:30 PM
      Coffee Break
    • 6th Session: Short communication from participants
      Convener: Akira Yamamoto (High Energy Accelerator Research Organization (JP))
      • 28
        A capital-cost and energy reducing configuration for dipoles in multi-stack race-track bends
        Some existing facilities (1) and the recent proposal for the LHeC collider (2,3), have utilised a racetrack configuration, with 180 degree bends, to circulate beam for a small number of turns (typically 3 revolutions) through superconducting energy-recovery linacs. Particles of differing energies are defected in these bends and this is accomplished by positioning the beams at different vertical positions, with different strength dipole magnets stacked vertically at the appropriate height for each beam. Conventionally, these dipoles are separately, individually, powered. However, the paper will present a revised geometry that allows coils to be shared between two adjacent vertically stacked dipoles, so contributing to the required Ampere-turns in both magnets. The resulting configuration reduces the total coil volume and hence the energy losses of the complete assembly. As an example, such a modified structure for the LHeC, configured according to the linac-ring option, would reduce the dipole coil volume and power loss by circa one third.
        Speaker: Neil Marks (STFC)
      • 29
        Development of a hybrid permanent magnets quadrupole
        The ESRF Insertion Devices laboratory is developing high gradient permanent magnet (PM) quadrupoles for potential use in a storage ring. This paper presents the development of a hybrid quadrupole with strong gradient (100T/m). The performance of a few PM and resistive structures are compared. One hybrid structure, composed of iron parts and rectangular PM blocks, appears to offer a good compromise between performance and technological complexity. This structure has an aperture in the horizontal plane for the X-ray beam port. It introduces field quality deterioration because of the structure asymmetry. Field quality repair work can be achieved in particular on the pole shape by optimization. Furthermore, the arrangement of the quadrupole elements allows a number of simple methods to correct the errors during the assembly.
        Speaker: Patrick Ngotta (ESRF)
      • 30
        The loss budget of the SIS100 fast ramped superferric magnets
        The superconducting magnets of the SIS100 heavy ion accelerator are to be built based on a compact window-frame design. Beside the optimisation of the magnetic field characteristics the minimisation of the AC losses was a central part during the R&D phase. Now the first dipole was built and tested. We presend the obtained loss results for typical operation modes and compare them with previous estimations and extrapolate these to the expected power consumption required for the quadrupole and corrector magnet. This will allow estimating the expected total energy consumption.
        Speaker: Anna Mierau (GSI)
      • 31
    • 6:30 PM
    • 7th Session: Beam dynamics, alignment, magnetic measurement requirements
      Convener: Michele Modena (CERN)
      • 32
        Beam dynamics requirements for future accelerators
        Speaker: Yannis Papaphilippou (CERN)
      • 33
        Magnet alignment challenges for future accelerators
        Speaker: Helene Mainaud Durand (CERN)
      • 34
        Magnetic measurements challenges for very compact magnets
        Speaker: Marco Buzio (CERN)
      • 35
        Nano-positioning possibilities for future accelerator magnets
        A subject common to several future high-energy physics R&D programs is the generation of beams with very small emittance and beam size and concomitantly the alignment and stabilization of accelerator components with ultimate precision. To reach e.g. the design luminosity at the CLIC interaction point, the beam size at the interaction point (IP) shall be only one nanometre in vertical direction and 45 nanometre in horizontal direction. About 4000 Main Beam Quadrupoles (MBQ) are needed to conserve such a small beam along the accelerator and final focus (FF) magnets will focus the two beams to collide at the IP. In addition to a very stringent alignment, the quadrupole positions should be stable to sub nanometre level and this for frequencies as low as 1 Hz. An active mechanical stabilization and positioning system based on very stiff piezo electric actuators and inertial reference masses is under study for the Main Beam Quadrupoles (MBQ). The stiff support was selected for robustness against direct forces and for the option of incrementally repositioning the magnet with sub nanometre resolution. The technical feasibility and the required stability level was demonstrated on several test benches, including a type 1 MBQ prototype (100 kg) with nominal magnetic field and nominal water flow. Technical issues were however identified and the development of the actuating support, sensors, and controller is still ongoing to increase the performance, integrate the system in the overall controller, adapt to the accelerator environment, and reduce costs. This presentation will show the type of components that can be used for actuating accelerator magnets with sub nanometer resolution and the technical parameters to be dealt with. Some R&D possibilities will also be indicated.
        Speaker: Kurt Artoos (CERN)
    • 10:30 AM
      Coffee Break
    • 8th Session: Summary and final discussions
      Conveners: Daniel Schoerling (CERN) , Michele Modena (CERN)
      • 36
        Summary of sessions 1&2
        Speaker: Akira Yamamoto (High Energy Accelerator Research Organization (JP))
      • 37
        Summary of sessions 3&4
        Speaker: Daniel Schoerling (CERN)
      • 38
        Summary of sessions 5&6
        Speaker: Jim Clarke (STFC)
      • 39
        General discussions