LNLS, Campinas
We present several alternative designs of hybrid bending magnets based on the use of ferrite blocks with steel pole pieces to be used in the new Brazilian storage ring - LNLS2. Their main magnetic and mechanical characteristics are presented. Such models are compared to electromagnet magnets, and some advantages and disadvantages are listed, as well as a cost estimate.
BNL, Upton, Long Island, New York
Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886
The NSLS-II light source is a proposed 3 GeV storage ring, with the potential for ultra-low emittance*. Despite the reduced emittance goal for the bare lattice, the closed orbit amplification factors are on average >50 in both planes, for random quadrupole alignment errors. The high chromaticity will also require strong sextupoles and the low 3 GeV energy will require large dynamic and momentum aperture to insure adequate lifetime. This will require tight alignment tolerances (~30microns) on the multipole magnets during installation. By specifying tight alignment tolerances of the magnets on the support girders, the random alignment tolerances of the girders in the tunnel can be significantly relaxed. Using beam based alignment to find the golden orbit through the quadrupole centers, the closed orbit offsets in the multipole magnets will then be reduced to essentially the alignment errors of the magnets, restoring much of the DA and lifetime of the bare lattice. Our R&D program to achieve these tight alignment tolerances of the magnets on the girders using a vibrating wire technique**, will be discussed and initial results presented.
*Work presented on behalf of the NSLS-II Design Team, CDR(2006) and CD2(2007).
**A. Jain, et al, International Workshop on Accelerator Alignment, Tsukuba, Japan, Feb.11-15, 2008.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
eRHIC, a future high luminosity electron-ion collider at BNL, will add polarized electrons to the list of colliding species in RHIC. A 10-to-30 GeV electron energy recovery linac will require up to six passes around the RHIC 3.8 km circumference. We are developing and testing small (3-to-5 mm gap) dipole and quadrupole magnets and vacuum chambers for cost-effective eRHIC passes. We are also studying the sensitivity of eRHIC pass optics to magnet and alignment errors in such a small-magnet structure. We present the magnetic and mechanical designs of the small gap eRHIC components and prototyping test results.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A steering magnet is not a major component in a beam line, however it is usually needed in any real set up. Also it is hard to estimate the required field strength before the beam line construction, since the strength needed is determined by misalignnment errors of other devises. Sometimes it is difficult to find enough space to install steering magnets because of other constraints on the length of the beamline. We compare two extreme designs of steering magnets. The first one is very thin steering magnet design which occupies only 6 mm in length and can be additionally installed as needed. The other is realized by applying extra coil windings to a quadrupole magnet and does not consume any length. We will present both designs in details and will discuss pros and cons.
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
Feasibility studies for two families of corrector magnets for NSLS-II are presented. The first family of magnets are generalizations of figure eight quadrupoles using rotationally symmetric breaks in the return yoke to fit in available space. Properties specific to figure eight magnet are identified. The second type of magnet is a combined sextupole/dipole trim.
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
The design and measurement of the NSLS-II ring quadrupoles prototypes are presented. These magnets are part of a larger prototype program described in [1]. Advances in software, hardware, and manufacturing have led to some new level of insight in the quest for the perfect magnet design. Three geometric features are used to minimize the first three allowed harmonics by way of optimization. Validations through measurement and confidence levels in calculations are established.
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
NSLS-II is a new state-of-the-art medium energy synchrotron light source designed to deliver world leading brightness and flux with top-off operation for constant output. Design and engineering of NSLS-II began in 2005 and the beginning of construction and operations are expected to start in 2009 and 2015, respectively. The energy of the machine is 3Gev and the circumference 792 m. The chosen lattice requires tight on magnetic field tolerances for the ring magnets. These magnets have been designed with 3D Opera software. The required multipole field quality and alignment preclude the use of multifunctional sextupoles, leading to discrete corrector magnets in the storage ring. The corrector magnets are multifunctional and will provide horizontal and vertical steering as well as skew quadrupole. This paper describes the dipoles, quadrupoles, sextupoles, and corrector magnets design and prototyping status of the NSLS-II.
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
Discrete corrector magnets are used for the 230 horizontal and vertical steering magnets in the NSLS-II storage ring. A unique design incorporates both dipole and skew quad correctors for(DC) steering in the same magnet. Separate AC (orbit feedback) correctors have also been designed. Comparison with alternate designs are presented as well as prototype measurements
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
The Sextupole magnets for the National Synchrotron Light Source (NSLS-II) have stringent performance requirements. These magnets have a faceted pole profile departing from the classic shape due to constraint imposed by the vacuum tube. Three different geometric features were used as parameters to minimize unallowed harmonics. Prototypes were measured and have confirmed the good field quality.
CIAE, Beijing
CYCIAE-100 is a 100 MeV, 200 muA H- cyclotron being constructed at CIAE. The tolerance of the magnetic field is as tight as 1.2 Gauss for isochronous field and 2 Gauss for first harmonics. Due to the absence of coil adjusting in this machine, a measure that helps to achieve a more compact structure (435 ton for the main magnet), the imperfection hence becomes a much more critical factor in our consideration. The effects by the various kinds of imperfection are investigated numerically and the imperfection fields are predicted for beam dynamics simulation, serving as a basic guidance in the magnet construction for CYCIAE-100. Some of the important results will be reported in this paper, including
- the deformation of the main magnet by the gravity itself, 480 ton EM force and 120 ton vacuum pressure,
- segregation, inclusion and contraction cavity induced by the casting procedure,
- fabrication and assembling tolerance, and
- thermal deformation.
CIAE, Beijing
TUB, Beijing
To limit the cost for the main magnet of a compact cyclotron CYCIAE-100, the cast steel is used for the top/bottom yoke and return yoke. The imperfection may not be ignored and the harmonic coils on the return yokes will make the fields reaching the requirements easier during the shimming. The centering coils will not only compensate the 1st harmonic fields at the center region, which is usually remain big, but also correct the off-center injection of the beam. The thermal deformation and the vacuum pressure may change the fields distribution during the machine operation and therefore It is necessary to use trim coils to adjust the fields. We arrange the trim coils inside the two opposite valleys of the main magnet. The second harmonics from the trim coils are not big eough to affect the beam dynamics significantly from the beam dynamics study. In this paper, the effects of correction coils of three types are presented. The detail configuration of the correction coils is introduced in the paper as well. One concern is the potential interference of some water cooled coils could have with vacuum. Some experience for the coils inside the high vacuum tank is tested and the results are given.
BINP SB RAS, Novosibirsk
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
BINP has manufactured and measured 243 multipoles of 9 types for the ALBA storage ring. The magnets had severe requirements on the manufacturing tolerances and the alignment of their magnetic axes. The quadrupole magnets are made of 1mm laminated yokes with the bore diameter of 61mm. The sextupole magnets are made of 0.5mm laminated yokes with the bore diameter of 76mm. Rotating coils and Hall probes have been used for the magnetic measurements. The features of manufacturing and magnetic measurements are presented in this paper.
Fermilab, Batavia
Funding: Work supported by the U.S. Department of Energy
The fabrication of the multi-element corrector magnets for the Fermilab Booster synchrotron has just been completed. These water-cooled packages include six different corrector types - normal and skews oriented dipole, quadrupole and sextupole elements. They will provide full orbit control, tune and chromaticity of the beam over the whole range of Booster energies, from 0.4 GeV to 8 GeV. During production, a set of quality assurance measurements were performed, including special thermal tests. This paper summarizes the results from these measurements as well as discussing some specific steps of the magnet fabrication process.
FZJ, Jülich
iThemba LABS, Somerset West
Funding: Work supported by BMBF and NRF, Project code SUA 06/003
Forschungszentrum Jülich has taken the leadership of a consortium responsible for the design, installation and commissioning of the High-Energy Storage Ring (HESR) for antiprotons as part of the FAIR project at GSI in Darmstadt, Germany. Since a normal-conducting design of the ring has now been favored over the previously envisioned superconducting option, new calculations have been performed in order to assess the magnetic field characteristics of the normal-conducting dipole, quadrupole, and sextupole magnets of the HESR. This paper presents the physical features of the magnets and the results of the 3D calculations with emphasis on the various multipole contributions at the ends of the magnets.
HIT, Heidelberg
GSI, Darmstadt
MPI-K, Heidelberg
The use of hadron beams delivered by normal conducting synchrotrons is highly attractive in various fundamental research applications as well as in the field of particle therapy. These applications require fast synchrotron operation modes with pulse-to-pulse energy variation and magnetic field slopes up to 10 T/s. The aims are to optimize the duty-cycle or to minimize treatment times for the patients as well as to provide extremely stable properties of the extracted beams, i.e. position and spill structure. Studies performed at the SIS18 synchrotron at GSI showed that not only the dipoles but the quadrupoles as well significantly contribute to the underlying time constants of the slowly extracted beam. An attempt has been made to measure the magnetic fields in synchrotron magnets with high precision and speed comparable to the current measurement with a DCCT. Additional magnetic field monitoring includes the retarding effects into the current control feedback loop neglecting the unfavourable dynamic effects from hysteresis and eddy currents. The presentation describes this controls approach, the results obtained at the HIT synchrotron and the SIS18 at GSI will be discussed.
KEK, Ibaraki
Tigold, Chiba 289-1226
KFG, NEUSS
KYOCERA Corporation, Higashiomi-city, Shiga
MELCO SC, Tsukuba
Nichicon (Kusatsu) Corporation, Shiga
The KEK Linac delivers the beam to KEK-Photon factory storage ring, KEKB ring and the advanced ring for photon factory. In order to deliver the beam to the KEK-photon factory and KEKB ring simultaneously, the pulsed bending magnet was installed at the end of KEKB Linac. The pulsed bending magnet extract 2.5GeV electron beam to the PF beam transfer line. The deflection angle of the magnet is 0.114 radians and the field strength is almost 1.22T. The peak current stability is better than 0.1% at 24kA operation. The maximum repetition rate is 25Hz. The 1.2m long ceramic chamber is inserted into the 1m long magnet. This system makes possible the top up operation of PF ring.
KEK, Ibaraki
KEKB linac is a 600 m long electron linac and is used to deliver beam to four rings, KEKB HER ring (electron, 8 GeV), KEKB LER ring (positron, 3.5 GeV),PF ring (electron, 2.5 GeV) and PF-AR ring (electron, 6.5 GeV). KEKB rings are operated under top-up injection mode and have occupied the current linac operation mostly. Simultaneous injection to three rings (KEKB HER and KEKB LER and PF) is required due to the top-up injection to PF ring is required recently. We have developed the pulsed bending magnet for this. This magnet produces 114 mrad deflection angle for 2.5 GeV PF beam. The fast switching between KEKB and PF can be performed up to 25 Hz. We will describe this magnet system in detail.
HUST, Wuhan
Funding: National Natural Science Foundation of China (No. 10435030)
A 10MeV H- compact cyclotron (CYCHU-10) is under construction in Huazhong University of Science and Technology (HUST). This paper presents a magnetic field measurement system for measuring the cyclotron magnet. A Hall probe and a granite x-y stage are adopted in the project. The Cartesian mapping will replace traditional polar system. The motion control and data acquisition system for the magnetic field measurement consists of a Teslameter and Hall probe, servomotors, a motion control card, optical linear encoder systems and an industrial PC. The magnetic field will be automatically scanned by this apparatus, and a flying mode will be the main running mode to reduce measure time.
HUST, Wuhan
Funding: Work supported by National Nature Science Foundation of China (10435030) and National Science Foundation for Post-doctoral Scientists of China (20080430973)
Low energy compact cyclotrons for short-life isotopes production delivered to the Positron Emission Tomography (PET) facilities have foreseeable prospects with growing demands in medical applications. The Huazhong University of Science and Technology (HUST) proposed to develop a 10MeV PET cyclotron CYCHU-10. The design study of the main magnet and the central region was introduced. A matrix shaping method with the radial fringe field effect and artificial control was adopted to obtain field isochronisms precisely. The central region was optimized to attain 35° RF phase acceptance and low vertical beam loss rate.
Kyoto ICR, Uji, Kyoto
KEK, Ibaraki
Funding: Work partially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (A), 18204023(2006)
Although the base line technology of the Final Focus Doublet for ILC is superconducting magnet, which is supposed to be conventional, the slender structure may be suffered from its vibration. The permanent magnets, however, do not have any vibration source in it at the steady state. The five-ring-singlet configuration, proposed by R. L. Gluckstern adds 100% strength adjustability to permanent magnet quadrupole (PMQ) lens. A prototype of this lens is fabricated and under evaluation. It was originally designed for ILC that also has the extra hole for the outgoing beam. In order to realize the beam test at ATF2, the inner bore is enlarged from D20mm to D50mm to clear the background photons from Shintake-Monitor. The magnet is described.
NSRRC, Hsinchu
The highly stable pulsed magnets are designed for injection and extraction the electron beams operation in Taiwan Photon Source. The injection to the booster at 0.15 GeV is performed with septum and kicker devices as well as the extraction from the booster at 3 GeV. There are 5 in-vacuum septum and kicker magnets used for booster injection and extraction processes. For the storage ring, an injection of the electron beam into the storage ring is performed with a septum magnet and four identical kicker magnets. All pulsed magnets are designed for injection into the 3-GeV storage ring. The kicker magnet is excited with a 4.8-μs half-sine current waveform. A prototype of kicker magnet with 0.6 m of length is made and tested for examining the field errors. The field performances of the kicker magnet are presented. All pulsed magnets are fed with special current waveform. Both pulsed magnets are considered with the goal to achieve reliable work.
NSRRC, Hsinchu
Abstract A 3-GeV electron-storage ring with tiny emittance has been designed for the Taiwan Photon Source (TPS) that will provide one of the world's brightest synchrotron x-ray sources. Sextupole magnets for the booster ring (BR) serve to correct the chromaticity of the beam particles. As an AC power supply is generally used in a booster ring to raise beam particles to a required energy, a power supply at 3 Hz AC is used to charge the sextupole magnet, which would induce eddy currents in the vacuum chamber resulting in a magnetic multipole field. As an aspect of the magnet design, decreasing the effect of an eddy current on the homogeneity of the magnetic field, the geometry and material of the chamber must be considered. We demonstrate the effects of an eddy current on the homogeneity of a magnetic field for a vacuum chamber of various types, and we discuss the magnetic circuit and the conductor design of the booster-ring sextupole. Analysis of the multipole field and eddy-current loss were included to assure the accuracy of the magnetic circuit design.
NSRRC, Hsinchu
The accelerator lattice magnets of the Taiwan Photon Source (TPS) with energy 3 GeV have been designed for the storage and booster ring. The magnetic computation codes of TOSCA and RADIA software packages were used to design the magnet circuits of the accelerator magnets. Meanwhile, the design of a magnet circuit must take into account both the requirements of accelerator physics and practical engineering constraints. The criterion of magnet design is to keep a rise of coil temperature within 10o C and a safety margin greater than 15 %. We apply pole edge shims and end magnet chamfers to enhance the field homogeneity and to decrease multipole components, respectively. The edge shim involves a smaller magnet dimension but maintains the same quality of the field. Use of an end magnet chamfer avoids field saturation. The mechanical engineering design of the storage ring magnets has been completed and the booster ring magnets have started to be designed. The 3D Solidworks package was used to draw and design the mechanical engineering. The prototype magnets of the storage ring have been contracted out to the local company in Taiwan and will be finished before the end of 2009.
NSRRC, Hsinchu
Lots of multipole magnets will be fabricated for the accelerator lattice magnets of Taiwan Photon Source (TPS) that include the storage ring magnets, booster ring magnets, and the transfer line magnets. Therefore, several precise rotating-coil measurement systems (RCS) with high speed measurement are developed to characterize the magnetic field of quadrupole (QM) and sextupole (SM) magnets. Printed circuit coil including normal-coil and bucking-coil, are applied to measure the absolute and relative values of multipole components, respectively. Normal-coils with three turns (single-layer-coil) has been previously discussed and found to have good reproducibility. Moreover, a 12-turn multi-layer-coil has been designed to characterize the booster ring multipole magnets of TPS. This study, compares the compensatory characteristics of two bucking-coils with 75/150 turns and 150/300 turns with those of normal-coil. A continuously-winding-method for bucking-coil is presented in the paper. A precision testing bench was used to test the performance of this system. This work describes the measurement system design and fabrication, and discusses the system precision and accuracy.
NSRRC, Hsinchu
Bending magnets, quadrupole magnets, and sextupole magnets are the most crucial magnetic elements in the synchrotron accelerator facility or high energy accelerator collider ring. Generally, separate bending magnets, quadrupoles or sextupoles magnets are utilized to perform separate functions. However, in the lattice design of accelerator ring or a compact ring in limited space, a single multifunction magnet is used to reduce the number of magnets and ensure that the entire device fits into the available space. This work presents an approach for designing the pole profiles of a combined-function bending magnet of the dipole, quadrupole, and sextupole components. The pole profile of a combined quadrupole magnet with gradient field and sextupole field components is also discussed.
ORNL, Oak Ridge, Tennessee
Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
3D computer simulations are performed to study magnetic field qualities in the SNS ring extraction Lambertson septum magnet. This work is motivated by the existence of a significant skew quad term in the magnet that has been identified as the source of causing a beam profile distortion on the target. The skew quad term is computed with different methods in simulations and is compared to measurement data. The origin of the large skew quad term is thoroughly investigated. The remedy for minimizing the skew quad term by modifying the magnet is also proposed. Particle tracking has been performed to verify the beam profile evolution through the existing and modified septum. The magnetic interference to the septum performance from an adjacent quadrupole is also assessed. This paper reports our simulation techniques and major results.
PAL, Pohang, Kyungbuk
Funding: Supported by the MOEST of Korea and by POSCO
Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. The key features of the upgrade are, decrease of the beam emittance to 5.6 nm, increasing the beam energy to 3.0 GeV, additional shorter straight sections for more insertion devices. Because the PLSII should use practically same circumference preserving the shielding wall structure of the existing PLS, the lattice space is squeezed to the limit to secure the additional space for the insertion devices. This requirements forces heavy use of the combined function magnet. All dipoles are replaced to gradient magnet, and all sextupoles have horizontal corrector winding, vertical corrector winding, skew quadrupole windings. In this report, the design features and engineering efforts for the PLSII magnet systems are reported.
PAL, Pohang, Kyungbuk
Funding: * Work supported by Korean Ministry of Education Science and Technology
The magnets for a medical synchrotron were designed. The synchrotron is for cancer therapy with proton and carbon-iron beams. The magnets for the injection include a septum magnet and an electrostatic septum magnet. And the magnets for the extraction include a resonance sextupole magnet, an electrostatic septum magnet, a thin septum magnet, and a thick septum magnet. The design achieved good field uniformity and acceptable leakage field level. We used 3D code for the electromagnetic simulation and the optimization of magnetic structures. In this paper, the basic design process for the injection and extraction magnets will be presented.
USP/LAL, Sao Paulo
Funding: FAPESP, CNPq
The IFUSP Microtron transport line guides the 5 MeV electron beam from the booster to the main microtron, where it can be accelerated up to 38 MeV in steps of 0.9 MeV. A few meters after leaving the main microtron, the beam is guided to the experimental hall, which is located 2.7 m below the accelerator room. The beam leveling is made by two 90° bending magnets. In the experimental hall there is a switching magnet to drive the beam to two different experimental lines. Each of these lines has another 90° bending magnet. These magnets were designed, constructed and characterized. In this work we present the analysis of the field distribution of these 90° bending magnets. Comparison between field simulation and data from field mapping is presented. We also present a reproducibility analysis where the field distributions of two twin magnets are presented.
Sigmaphi, Vannes
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The paper presents the magnetic measurements of the 32 long dipoles and 8 short dipoles magnet manufactured by Sigmaphi for the ALBA synchrotron booster based in Spain. An extensive set of measurements based on search coils was made by Sigmaphi to characterize the magnetic field at different currents. This paper describes the magnetic measurements results. The measurements show the maximum field integral deviation between the magnets is within ± 3.10-3 as expected.
JLAB, Newport News, Virginia
Funding: Work supported by the US DOE Contract #DE-AC05-060R23177 and the Commonwealth of Virginia.
The characteristics of the system of “SF” Sextupoles for the infrared Free Electron Laser Upgrade at the Thomas Jefferson National Accelerator Facility (JLab) are described. These eleven sextupoles possess a large field integral (2.15 T/m) with ± 0.01% field quality over a 150 mm width within a very short effective length (150 mm pole length) and have field clamps for fast field roll-off. The field integrals reproduce extremely well with good absolute resolution (± 0.1%). The simple, two-dimensional shape pole tips (directly from the original 3-D RADIA magnetic model) of these “all ends” magnets include the correction for end fields. Magnetic measurements are compared to the model. The system’s hysteresis protocol and power supplies were also used for the measurement process to enhance reproducibility in service, a recent initiative at JLab. The intricacies of magnetic measurement using the JLab field probe based Stepper Stand are described. The challenges of developing the in-house design power supplies for these magnets, based on use of a low quality supply brought to 0.001% current regulation by a CAN-Bus control are described.
JLAB, Newport News, Virginia
Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) currently has maximum beam energy of 6 GeV. The 12 GeV Upgrade Project will double the existing energy and is currently scheduled for completion in 2014. This doubling of energy requires modifications to the beam transport system which includes the addition of several new magnet designs and modifications to many existing designs. Prototyping efforts have been concluded for two different designs of quadrupole magnets required for the upgrade. The design, fabrication and measurement will be discussed.
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
USTC/NSRL, Hefei, Anhui
HALS(Hefei Advanced Light Source) is the electron storage ring of ultra-low emittance in process of design. Under this design, the quadrupole magnet with sextupole component must be mounted on which the βη is much bigger, to use enough the effect of compersation chromaticity of sextupole magnet field and to use sparingly the space in the same time . So the combined quadrupole and sextupole magnet must be designed, and have more strong sextupole component and restrain the production of high harmonic field. In this paper, the chocie of design scheme is discussed, and the calculation of combined quadrupole and sextupole mangnet design is given.
BNL, Upton, Long Island, New York
Funding: US DOE Office of Basic Energy Sciences
This paper will describe the requirements, the design and the prototype test results of the magnets for the new synchrotron radiation source NSLS-II now under construction at BNL. Several innovations have been incorporated in the design, in manufacturing and in the alignment procedures of the magnets. Prototypes of these magnets have been built in industry. A dipole design has been developed with a maximized magnetic length which is longer than the mechanical length. The quadrupole and sextupole magnets of NSLS-II must be aligned and positioned to better than 30 microns, a level never achieved before in such accelerators. The paper will present a brief status of the progress made in the techniques developed to measure and achieve these demanding requirements. Another concern has been the distortion of field quality due to the small (150 mm) axial spacing between the iron-yoke of two adjacent magnets. Calculations (in 3-D) and the result of systematic measurements of the field quality in the presence of other magnets and other machine components in close proximity will be presented.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
The latest initiatives to design and build non-scaling FFAGs have encountered novel technical challenges; the required DC combined function magnets (normal and superconducting) and fast pulsed magnets for injection and extraction present new problems. The talk will report on progress in meeting these challenges for the non-scaling machines, EMMA and PAMELA and will provide details of their current design status. With the main EMMA ring magnets now being delivered and the injection and extraction magnets being assembled in-house, practical engineering features of these systems will be presented.