Panel Discussion on Single Particle Codes 1.Catalogue of existing codes 2.Transparency of input and output between different codes: what is the status of SXF? Is it still 'alive' and who has used it for which codes? 3.Combination of single particle tracking and non-linear tools: What compromises in speed versus flexibility are practical? How can / is the non-linear analysis interfaced to the tracking data? What compromises in versatility and maintainability are reasonable? 4.Possibility of real time simulations: What compromises between speed and accuracy are acceptable? Option of 'one turn map' tracking? 5.Wish list for additional features in single particle simulation tools: Tracking with dynamic effects? Tracking with acceleration (normal and recycling linacs)? Tracking with aperture and absorbers / collimators? Collective effects such a space charge? 6.Managerial issues for code development and maintenance in large collaborations: How can the experience with MAD9 be avoided in existing collaborations? Panel Discussion on Single Particle Codes Panel members: O.Brning CERN, W. Decking, F. Meot CEA, K. Ohmi KEK, F. Schmidt CERN, J. Wenninger CERN Additional people contacted: R. Assmann CERN, H. Grote (CERN), W. Herr CERN, E. Keil (CERN), S. Peggs BNL, F. Pilat BNL, G. Robert-Demolaize CERN, S. Redaelli CERN, F. Ruggiero CERN, R. Talman CORNELL, T. Sen FERMILAB, F. Zimmermann CERN Replies received: 2 presentations, 1 submitted presentation (not shown) 2responses, ideas from other HHH sessions Limited Discussion: summary reflects not necessarily the community as a whole Describes the motion of a particle in the 6 dimensional phase space under the influence of external fields Linear Motion Fitting of linear optic functions etc. Definition of magnets and alignment Definition of geometry Nonlinear Motion Nonlinear perturbations Dynamic Aperture Definition W. Decking W. Decking: 26 existing codes (probably not complete) W. Decking Input Format Basic Lattice Design Performance Simulation Modelling of real machine construction (Typical) Life Cycle of an Accelerator Project (from N. Walker) Input Format should support all stages of the project Input Format Performance Simulation Modelling of real machine construction Basic Lattice Design Simple models (sequences of elements) Tend to work with smaller modules Fitting, constraints etc. Lattice matching Generic magnet families Definition of basic parameters (may have more than one possible optics) Quadrupole L K1 value or range of K1 values (Typical) Life Cycle of an Accelerator Project (from N. Walker) Basic Lattice Design Input Format Modelling of real machine construction More complex (complete) models Tolerance studies Simulation of a range of errors Refinement of parameter specifications Definition of prototype component Tuning algorithms, diagnostics specs. Power supplies (circuits), Klystrons etc. Performance Simulation Quadrupole L Pole tip radius max / min pole-tip field Tolerances (used to generate random errors) (Typical) Life Cycle of an Accelerator Project (from N. Walker) Performance Simulation Basic Lattice Design Input Format Modelling of real machine Engineering design of accelerator components Quadrupole prototype (family) L Pole tip radius max / min pole-tip field Tolerances Documentation (drawings, cad files etc) construction (Typical) Life Cycle of an Accelerator Project (from N. Walker) Panel Discussion on Single Particle Codes Need for specialized codes at different project phases / aspects example LHC: bare lattice design lattice with real aperture model and field errors Confidence and trust in codes builds up over years of experience: people are reluctant to change their code Need to combine single particle dynamics with other effects: Example: aperture, rest gas ionization, scattering, space charge effects etc use of several specialized codes Toolkits and modular program structures are highly desirable and a standard input format is the prerequisite for a comparison between different tools / codes! SIS100 Storage Mode Lattice Collimator distance from beam axis Collimation efficiency Missing dipole concept creates flat minimum dispersion function Storage mode lattices provide 100% collimation efficiency at maximum acceptance P. Spiller Simulation Code Development Integrated time resolved loss and pressure calculation must comprise: Initial residual gas composition Initial systematic beam losses (e.g. multi turn injection) Projectile and target ionization cross sections and resulting ionization degree and multiple ionization degree Collimation efficiency for the generated ionization degrees Effective desorption rate of the collimation system Realistic pumping power for the different residual gas consitutents Desorption coefficients and assumptions for the desorped masses. Desorption created by target ionization. Energy dependence of collimation efficiency and cross sections. P. Spiller Panel Discussion on Single Particle Codes Universal machine description format: SXF SXF is extensively used at BNL to transmit the machine description from the operation (stepping stones) to offline analysis (S. Peggs) How should SXF be improved? (R. Talman): XML, ADXF How many existing codes support SXF? Panel Discussion on Single Particle Codes MADX as an example for combining several applications or modules with a general Input parser into one coherent program MADX combines general optics and tracking routines with sophisticated toolkits such as Differential Algebra and post processing tools. Modular program structure allows straight forward integration of new modules and provides maintainability of the code. Single Particle Codes at CERN MAD-X Core in C Independent Modules (C, F77, f95 welcome) Drop messy modules Optimize for easy module inclusion New Management Style: One custodian + many module keepers Encourage international Collaboration (KEK, BNL, Frascati, GSI, SLAC, Cornell, ITEP) Tracking exported for LHC to highly optimized SixTrack +run-environment MAD-X converter module LHC tracking Collimation (different task same code!) SXF (in & out) to communicate with other codes (BNL module) Upgrade path PTC from E. Forest (f95, objects, polymorphism) Better Physics Model Normal Form and Parameter Dependence Proper Magnet Tunnel Relation including 3D Coordinate Transformations Panel Discussion on Single Particle Codes 1.Catalogue of existing codes presentation by W. Decking and F. Meot 2.Transparency of input and output between different codes: what is the status of SXF? SXF is used in BNL but not for code comparisons. 3.Combination of single particle tracking and non-linear tools: What compromises in speed versus flexibility are practical? How can / is the non-linear analysis interfaced to the tracking data? What compromises in versatility and maintainability are reasonable? 4.Possibility of real time simulations: What compromises between speed and accuracy are acceptable? Option of 'one turn map' tracking? both questions need to be addressed in the future for online modeling in the control room 5.Wish list for additional features in single particle simulation tools: Tracking with dynamic effects? Tracking with acceleration (normal and recycling linacs)? Tracking with aperture and absorbers / collimators? Yes Collective effects such a space charge? Yes 6.Managerial issues for code development and maintenance in large collaborations: How can the experience with MAD9 be avoided in existing collaborations? MADX