RFQ Integrated Design Would like to have a method of designing RFQ where all steps are integrated: –Engineering design. –EM modelling. –Beam dynamics simulations. Integrating design steps allows us to characterise effects of: –Fringe fields and higher order modes. –Limitations of current modelling techniques. –Thermal and mechanical stress limits. –Particular CNC machining techniques and options on beam dynamics. 24/02/11Simon Jolly, Imperial College London 1

RFQ Integrated Design Steps 24/02/11 RFQSIM Inventor (CAD) Comsol GPT Matla b Integrate RFQSIM, Inventor, Comsol, GPT and Matlab Excel Matla b 2Simon Jolly, Imperial College London

CAD & E-field Modelling Electrostatic field mapping in Comsol almost complete: –Semi-automated modelling of individual cells: almost fully automated, just working out the gremlins… –Already produced high resolution field map from CAD model for beam dynamics simulations. –Currently focusing on design of matching-in and -out sections. CAD modelling of vane tip modulations now complete: –Using values in Excel spreadsheet, possible to create arbitrary vane modulation design up to 1,000 cells in less than a minute. –Vane tip modulation model already added to bulk FETS RFQ CAD model: ready for machining. 24/02/11Simon Jolly, Imperial College London 3

Beam Dynamics Simulations 24/02/11Simon Jolly, Imperial College London 4 Energy Spread (60mA) Transmission (60mA) Beam dynamics simulations carried out in GPT using field maps. For nominal 60mA beam, CAD- based field map gives very similar results to coefficient-based field map from RFQSIM (A. Letchford): –>92% transmission of particles above 2.9MeV. –Slight difference in energy spread and transmission: CAD-based map gives better transmission at high currents!