docA6-Kishek - UMER - University of Maryland
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A6-Kishek - UMER - University of Maryland
Modeling and Simulation Rami A. Kishek, Irving Haber, & Max Cornacchia Outline: 1. Codes, Models and Strategies 2. Experiment / Simulation Comparison • Transverse • Longitudinal 3. Beam Halo Studies Funding Provided by US DOE and DOD 1 UMER Modeling Challenges SD4 •• Magnets Magnetswith withextended extendedfringe fringefields fields •• Earth Earthfield field •• Complicated ComplicatedInjection Injectionsection section Injector •• 14 14BPMs BPMsfor fortune tuneof of~~6.5 6.5 •• 88types typesof ofmagnets magnetsto tobe bemodeled modeled SD5 Q6 SD6i YQ PD QR1 SD6r Ring 2 Codes Used to Model UMER • WARP, developed by Grote, Friedman, Vay, Lund, et al., (LLNL/LBNL) – – – – – Electrostatic PIC code + accelerator code (used in Ion community) self-consistent treatment of space charge full set of accelerator element models XY, RZ, and 3D - curved coordinate system (no reference trajectory) has been extensively used in the design of UMER, and in modeling of many experiments and diagnostics ELEGANT, developed by Borland (Argonne) – a powerful particle tracking code – broadly used – includes optimization routines – so far have not used space charge model but code useful for characterizing lattice Other OtherCodes CodesUsed: Used: COSY COSYInfinity Infinity(NIU) (NIU) DIMAD DIMAD(MSU) (MSU) MaryLie MaryLie WinAgile WinAgile Envelope Envelopecodes codes ORBIT ORBIT(proposed) (proposed) 3 Magnet Models Sources of Magnet data – Rotating Coil measurements of harmonics of dipoles and quadrupoles – Hall probe measurements of magnets – MagLi: a Biot-Savart Law solver for air-core magnets Implementation: – hard-edge ideal magnets – hard-edge elements with multipoles Both Codes WARP ELEGANT – fringe field corrections – z-varying multipoles – actual fields on a 3-D mesh (derived from MagLi, typically with 1 mm resolution) 4 Key Strategies • Multi-turn operation and increased accuracy in experiments requires more refined simulation models. • Ongoing Work: – Re-survey of the machine for more accurate positioning (Sutter, Koeth, Ponter) – Re-measurement of magnetic fields (Bernal) and refinement of MagLi models (Kishek) – Cross-checking of magnet modeling between WARP and ELEGANT (Cornacchia and Kishek) – Benchmarking both codes against increasing volumes of experimental data: orbits, tunes, chromaticities, momentum compaction, resonances 5 Comprehensive modeling (UMERGeometry WARP module) WARP repository that includes: – descriptions and choice of models for every single lattice element • quadrupoles, dipoles, steering dipoles, injection pulsed magnets • Earth field data and Helmholtz coil information • induction cells – models of certain diagnostics and procedures for data processing parallel to those used in experiment meters – Can read/write file formats for UMER settings from experiment 0.2 0.0 H0 B0B1 0.0 R. Kishek B2 H1 0.2 B5 B4 B3 P0 0.4 meters B7 B8 P1 H2 B6 0.6 0.8 B0 B107 B1 P0 B106 P35 B2B3 B105 H2 B4 P1 B102 B103 B104 P34 B5B6 H1 B101 B7 P2 B100 P33 B8B9 B99 H0 B98 B10 P3 P32 B97 B11 B96 B12 B95 B13 P4 P31 B94 B14 B93 B15 B92 B16 P5 P30 B91 B17 B90 B18 B89 B19 P6 P29 B88 -1 B87 B20 B21 B86 B22 P7 P28 B85 B23 B84 B24 B83 B25 P8 B82 P27 B81 B26 B80 B27 B79 B28 P9 -2 P26 B78 B29 B77 B30 P25 B76 P10 B31 B75 B32 B74 B33 P24 B73 P11 B34 B72 B35 B71 B36 P23 B70 P12 B37 B69 B38 -3 B68 B39 P22 B67 P13 B40 B66 B41 B65 B42 P21 B64 P14 B43 B63 B44 B62 B45 P20 B61 P15 B46 B60 B47 B59 B48 P19 B58 P16 B49 B57 B50 B56 B51 P18 B55 P17 B52 B54 B53 0 -1 0 meters 1 6 ELEGANT Benchmark with experiments • Equilibrium Orbit (used ELEGANT to fit quadrupole displacement errors) • Lattice and Dispersion function • Chromaticity • Momentum Compaction Max Cornacchia 7 Resonance Simulations with WARP 4-turn Fractional Tune from WARP Δνcoh Chao Wu 8 Longitudinal End Expansion – Effect on Beam WARP simulation prediction, 1998 Beam Current R. Kishek 9 Z WARP Modeling of Beam End Erosion and Re-bunching Detector measures only peak-to-peak current Experiment WARP Simulation Irv Haber, Brian Beaudoin 10 WARP Simulation of Halo from Source R’ Halo Particles < 2007 23 mA d = 0.5 mm 2008 d = 0.1 mm 23 mA R d Grid K Haber, et al., NIM-A 606, 64 (2009). 11 Halo Studies Investment in Halo Diagnostics (1st turn) – Fast imaging (~ 3 ns resolution) see talk by Ralph Fiorito – Tomographic Phase Space Mapping – Optical Masking of Beam Core Simulation Studies using WARP – Halo Origin, Collimation, and Regeneration R-R’ R-R’ Z = 100 m Z=0m see talk by Christos Papadopoulos R-R’ Z = 100 m 12 Phase Space Tomography Tomography is the technique of reconstructing an image from its projections Quad Screen RC3 y x y’ RC6 RC9 Stratakis, Kishek, Li, et al., PRSTAB 9, 112801 (2006). Stratakis, Tian, et al., Phys. Plasmas (Lett.) 14, 120703 (2007). Stratakis, Kishek, Fiorito, et al., PRSTAB 12, 020101 (2009). Stratakis, Kishek, Haber, et al., PRSTAB 12, 064201 (2009). space charge, solenoids, time-resolved 13 emittance growth and halo Tomography Diagnostic and WARP Modeling Initial distribution y x 2.5-D WARP (PIC) Simulation Predictions vs. Tomography Simulation Prediction Experiment R. Kishek, AAC 2002 Uniform Focusing tomography Simulation Downstream X-Y X-X’ Memory of beamlets! D. Stratakis, 2007 14
