Magnet Design

The most important thing we build is trust

Magnet Design magnet-design-software.com

“I need a solution-provider, not a software vendor”

Cobham Technical Services - Vector Fields Software has nearly 30 years’ experience in the development of advanced software for electromagnetic simulation. The scope of the Opera software suite has been driven by scientific and industry require-ments to ensure its relevance to end-users. The software is fast, accurate, and provides a cost-effective engineering solution to real-world design problems. In addition to supplying leading-edge software, we passionately believe in providing users with the support they need to get the best from Opera. This includes training and help using Opera. We also employ experts in the principal engineering and scientific applications that Opera is used for so that we have a detailed understanding of user requirements and are able to provide in-depth application-specific assistance when this is required. We believe that many of our customers value the combination of high performance software and the atten-tive support offered by Cobham. As a re-sult, customers include some of the largest and most advanced producers of electro-magnetic devices and systems from many industries as well as prestigious research laboratories and academic institutions.

“In an accelerator magnet, magnetic fields are used to steer and focus charged parti-cle beams. What tools does Opera have to rapidly assess field quality? And can I see how the particle beams behave?”

Opera’s post-processor includes tools for characterizing field homogeneity or gradients in free-space volumes. For dipole, quadrupole and higher order multi-pole magnets, characteristics are usually calcu-lated as a set of Fourier coefficients on a circle or part circle. Similar functions are also available to display field homogene-ity on spherical surfaces. Field values can be calculated at any point and Opera can directly track individual charged particles or systems of particles through or beyond the magnetic aperture. Results can be displayed in various ways, including:

• 3D track lines through the geometry• projections onto the major coordinate

planes• intersection points on any 2d plane• current or power density maps

“That sounds very powerful. Can I auto-mate the process?”

Opera has a powerful scripting language which enables any frequently performed

So much of science and technology is reliant on magnets, from electric motors to the most advanced experimental research into particle physics. For nearly 30 years, the Opera finite element (FE) software for electromagnetic design has been used by scientists and engineers for designing and optimizing magnet systems to achieve the most demanding levels of performance. Opera has earned its position as the foremost FE design tool for magnets of all types by its consistent accuracy, ease of use, and ability to handle large and complex simulations routinely.

Opera is widely used by the scientific community for designing magnets for use in particle accelerators, ion-beam devices, MRI/NMR and a wide variety of other magnetic devices. The application focussed software has evolved over the years and today provides comprehensive multi-physics simulation that is capable of investigating thermal and stress in addition to electromagnetics. The software can also track charged particles through electromagnetic fields.

actions to be programmed into a macro file. Once the design process has been cap-tured through an interactive session, the logged commands can be used to generate a first version of the macro, which can be subsequently extended and modified as requirements change. This also allows the creation of customized interfaces to Opera supporting parameterization, making use of the language’s tools for the user to de-fine their own dialogs. The parameters can be used to define geometry, set up analy-ses and run extensive post-processing.

“I’m looking at pulsed magnets – kick-ers and so on – can Opera model these, especially the redistribution of currents in the conductors? And how does it deal with laminations?”

Opera can perform transient simula-tions with a user-defined pulse for either the current in, or the voltage across the winding. The simulation is able to capture skin-effects and proximity effects. For magnets built using laminations, Opera has a material model that can treat a bulk volume – such as the magnet yoke - as a “packed” structure, thereby removing the need to model the individual laminations. The designer only needs to specify the packing factor of the lamination stack and the orientation of the plane of the lamina-tions.

“What physics can Opera capture in the superconducting windings of my magnet?”

In most cases superconducting magnets can be accurately represented using stand-ard coil models. However, Opera includes comprehensive facilities for modelling the detailed physics of superconductors when it is necessary to do so, for exam-ple shielding produced by super-currents under Meissner effect conditions, or the hysteretic behaviour as a magnet current is ramped up and down. Opera’s most sophis-ticated model for superconducting wind-

Accelerate and optimize your design with the Opera simulation software Design > Simulate > Analyze > Optimize

ings is to simulate a quench. The Opera-3d quench simulator solves the time-transient coupled thermal and electromagnetic equations. The tool is able to model com-plete coils connected to supply/protection circuits and evaluate the effectiveness of the protection. Simulations can include heating from eddy currents in formers and support structures. Whilst Opera can simulate quench in a complete coil or system of coils, it can also model individual superconducting wires of both LT and HT superconductors.

“Can Opera model any other components in a particle accelerator?”

Yes, Opera can model RF resonant cavities to determine its Eigen frequencies and to display the electromagnetic fields to analyse mode shapes. Cavity Q-factors can be calculated for each mode. Other simula-tions can be performed to determine the effect of imperfect (lossy) dielectric materials, allowing the designer to assess the associated shift in resonant frequency and re-evaluate the Q-factor. Opera has extensive facilities for modelling charged particle beams and plasmas, that can be used to model components such as ion sources. More information on this can be found on our dedicated website http://charged-particle-devices.com/

“How do I know the software will be ac-curate?”

Opera is an established finite element analysis product that has been exten-sively validated for many applications. In particular, its magnetic field predictions are recognised as being very accurate. Opera is widely used by the scientific community because it is known to be accurate, effi-cient and capable for the most demanding of applications. Please refer to our magnets website (magnet-design-software.com) for a wide range of journal publications that highlight these points.

In Brief

Opera is software for electromagnetic design that can model virtually any type of electromagnetic device. It is widely used by the scientific community for magnet designs used in accelerators, other physics experiments and a variety of other applications. It includes a special solver for modelling the highly transient and non-linear progression of a quench process.

Capabilities for Designers:

• 2d and 3d device evaluation using advanced Finite Element simulation• Full non-linear and locally orthotropic

material representations for both electromagnetics & thermal• Full anisotropic structural materials• Accuracy comparable with measurement• Rapid testing of design variants• Test under real-world conditions (i.e.

across all operating and under fault conditions)• Include the power supply and load• Include thermal and structural analysis• Include magnetic hysteresis

Standard results include:

• Field distribution• Field homogeneity and gradients• Fourier analysis coefficients• Peak fields on coils• Stray field / shielding effectiveness

(EMC/EMI)• Particle beam trajectories• Dynamic performance of pulsed

magnets• Forces and losses - coils, yokes and

shielding• Deflection and stress due to mechanical

loading• Cool down pre-stressing• Quench propagation• Protection circuit performance• Inter-turn / inter-layer voltages• Eigenfrequencies and Q-factors

Magnet Design

Accelerators Bending & Seperating

Confinement Focussing

RF Cavities PermanentMagnets

MRI/NMR Wigglers &Undulators

Cobham Technical Services Vector Fields Software

UK

Network House, Langford Locks, Kidlington, Oxfordshire, OX5 1LHT: +44 (0)1865 370151F: +44 (0)1865 370277E: vectorfields.info@cobham.com

operaFEA.com magnet-design-software.com

USA

1700 N Farnsworth Ave,Aurora, IL 60505, USA. T: +1 (630) 851 1734F: +1 (630) 851 2106E: vectorfieldsinc.info@cobham.com

Software Tools

• 2d & 3d modelling• Solid modelling capability• Coupled physics• Parameterization• Optimization• Graphical circuit editor• CAD import• Simulink® integration• Sumitomo HTS material

library

Multiphysics Capabilities

• Electromagnetics (statics,steady state & transient)

• Hysteresis• Eddy currents• Stray fields (EMC/EMI)• Losses• Forces• (De-)Magnetization

• Thermal (steady state & transient)

• Quench

Customer Support

We provide support to Opera users from our offices in the UK and the USA, and through a worldwide network of local distributors. Our support engineers have an extensive knowledge of all types of magnets and are available to assist both existing and prospective customers with their design requirements. In addition, regular training courses are held, which provide “hands-on” training in the use of Opera for designing these types of systems. Whatever your application and wherever you are located, you can be sure of our interest and support.

The accuracy provided by finite element simulation is a vital part of the development process to design magnets, companies who use these techniques are able to differentiate themselves with optimal design performance, short development timescales, and cost-effective manufacture. Cobham has nearly 30 years’ experience working with foremost manufacturers to produce some of the most accurate and functionally advanced software for magnet design.

For more information about Opera and the numerical simulation of magnets, please refer to the relevant technical data sheets and application notes. They can be obtained from our website, magnet-design-software.com, which is dedicated to the finite element modelling of all types of magnets and is a repository for technical articles and information about magnet design. The website contains information, including a range of technical publications, videos and webinars, that is of general interest to engineers involved in magnet design.

©2013 Cobham Technical Services. Specifications subject to change without notice. Any trade names or marks used are the property of their owners and are recognized, including Simulink (a trademark of MathWorks).

Applications

• Bending/seperating magnets• Focusing magnets• Wiggler/undulator magnets• MRI/NMR magnets• Acccelerator magnets• Permanent magnets• Confinement coils• Gradient coils• Superconducting magnets• RF Cavities

Magnet Design

The most important thing we build is trust

• Mechanical (forces/loads can be generated from other physics, defined or imported)

• Stresses & strains• Deformation• Thermal expansion• Magnetostriction• Eigenfrequency• Linear elastic/small

displacement