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

2. 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

3. 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

4. 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

5. 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

6. Next activity plan

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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