Summary & Concluding remarks The Concluding meeting on RIKEN AVF Cyclotron Upgrade, November 19, 2008 Summary & Concluding remarks Sergey Vorozhtsov

Principal achievements (1) Computer model development Completion of the electromagnetic field computer model Validation by the measurements Providing RIKEN users with the 3D simulated electrical and magnetic field maps, and the model geometrical structure for beam dynamics study Ready to pass the Tosca files to RIKEN users Progress in construction of the beam dynamics model Calibration by the experiments with the Nitrogen beam Cross check with the RIKEN code November 19, 2008 Sergey Vorozhtsov

Principal achievements (2) New acceleration regimes (1) 11 MeV/u Oxygen acceleration with limited dee voltage Generation of the magnetic field map with the newly proposed set of the trim and main coil currents Proposal of the cyclotron settings Optimal buncher voltage New inflector voltage RF phase at the 1st acceleration gap Modification of the central field bump Tracing of the reference ion from the buncher entrance until the ESD mouth Estimation of the beam transmission in the most critical region: buncher – 20th cyclotron turn. Providing all needed information for the beam tests in December 2008 November 19, 2008 Sergey Vorozhtsov

Principal achievements (2) New acceleration regimes (2) 60 MeV Proton acceleration RF 1st harmonics Generation of the magnetic field map with the newly proposed set of the trim and main coil currents Initial assessment of the beam dynamics. November 19, 2008 Sergey Vorozhtsov

Principal achievements (3) Analysis of the existing regime 7 MeV/u Nitrogen acceleration: Proposal of the optimal inflector cutting. Discovery of the impact of the asymmetrical Dee voltages on the beam centering. Calculation of the harmonic coil settings to take into account the beam precession, induced by the asymmetrical dee voltages. Estimation of the ESD optimal parameters for deflection of the beam. November 19, 2008 Sergey Vorozhtsov

Next activity plan

Computer model upgrade Compare once again the simulation and the experiment with respect to the beam position, beam width, injection efficiency, etc. Higher order effects evaluation in the LEBT against other similar existing program (PBO Lab etc). November 19, 2008 Sergey Vorozhtsov

New acceleration regimes 60 MeV Proton acceleration RF 1st harmonics Estimation of the cyclotron settings Assessment of the beam dynamics November 19, 2008 Sergey Vorozhtsov

Axial injection (1) Chopper Introduction a chopper upstream the buncher to clean up the injected beam in the cyclotron central region Buncher Estimation of the effect of two bunchers (Linear buncher – upstream and Sin buncher – downstream) in the LEBT Recalculation the LEBT SC effects for corrected buncher field distribution. November 19, 2008 Sergey Vorozhtsov

Axial injection (2) Electric quadruple Inflector Simulate the effect of an electric quadruple at the immediate upstream of the inflector on the beam quality Some space for the installation of an electric quadruple at the immediate upstream of the inflector was found! An electric quadruple of ~15 mm in bore diameter and several mm in length could be placed there. Checking by simulations whether it is effective or not. Inflector Study a new inflector shape with axial focusing of the beam Continue beam space charge effects impact estimation: FFT for inflector curvilinear surfaces. November 19, 2008 Sergey Vorozhtsov

Central region (1) Compare simulation and experimental data for 11 MeV/u 16O7+ ion beam Complete the design of the optimal geometry of the center region for the existing regime (RF 2nd harmonics) Shift outward radially the 1st Dee channel to better match to the entering beam Make the CBDA code to calculate the acceptance of the AVF November 19, 2008 Sergey Vorozhtsov

Central region (2) Assessment of the amplitude of the particle axial oscillations distortion due to Glaser lenses distortion of the magnetic midplane. Beam space charge effects impact estimation The backward 6D matching, i.e. obtaining the prescribed phase space out of the inflector November 19, 2008 Sergey Vorozhtsov

Extraction Calculation the extraction orbit in the deflector when a beam enters it with an inclined angle of ~ 10 mrad Simulation of the beam extraction for Nitrogen, Oxygen, Proton regimes November 19, 2008 Sergey Vorozhtsov