Patent Number: 
Section: claims

1. A method for controlling deflection of an ion beam, comprisingproviding an electrode configuration comprising a plurality of upper and lower electrode pairs, the upper and lower electrodes of each pair positioned on opposite sides of an ion beam;grading a deceleration of the ion beam,obtaining a deflection factor function along a length of the lens to obtain a beam angle correction; andobtaining electrode voltages for the plurality of upper and lower electrode pairs to adjust the grading, the deflection factor, and a focus of the ion beam such that a central ray trajectory (CRT) of the ion beam is positioned at a center of the lens center;wherein adjusting the grading and deflection factor is achieved using at least one virtual knob that adjusts at least one parameter of the ion beam. 2. The method of claim 1, wherein the at least one virtual knob controls the beam focus and residual energy contamination. 3. The method of claim 1, wherein the at least one virtual knob controls an upstream electron suppression of the ion beam, preventing electrons from being stripped from the ion beam. 4. The method of claim 1, wherein the at least one virtual knob controls a deflection of the beam, and centers the beam at the exit of the lens. 5. The method of claim 4, further comprising measuring currents on inner and outer final ground electrodes of the plurality of electrode pairs, and centering the beam by varying beam deflection until the currents on the inner and outer final ground electrodes are equal. 6. The method of claim 4, further comprising providing a collimated light sensor vertically centered within an exit aperture of the lens to determine beam centering. 7. The method of claim 1, wherein the at least one virtual knob controls a final deflection angle of the ion beam and constrains the position of the ion beam at the exit of the lens. 8. The method of claim 1, wherein the step of grading a deceleration of the ion beam further comprises calculating the energy of the beam's central ray trajectory (CRT) along a length of the lens. 9. The method of claim 1, wherein electrode voltages are assigned to the upper and lower electrode pairs such that voltages of outer electrodes of the plurality of upper and lower electrode pairs remain negative. 10. The method of claim 1, wherein an outer suppression electrode of the plurality of electrodes remains below an upstream beamline potential. 11. A system for controlling deflection of a charged particle beam, comprisinga graded lens comprising a plurality of sets of electrodes, each set of electrodes spaced apart by a gap to allow a charged particle beam to pass therebetween;a controller for controlling different combination of voltage potentials to be applied to the plurality of sets of electrodes; anda machine readable storage medium encoded with a computer program code such that, when the computer program code is executed by a processor, the processor performs a method comprising:grading a deceleration of the ion beam,obtaining a deflection factor function along a length of the lens to obtain a beam angle correction; andobtaining electrode voltages for the plurality of upper and lower electrode pairs to adjust the grading, the deflection factor, and a focus of the ion beam such that a central ray trajectory (CRT) of the ion beam is positioned at a center of the lens center;wherein adjusting the grading and deflection factor is achieved using at least one virtual knob that adjusts at least one parameter of the ion beam. 12. The system of claim 11, wherein the at least one virtual knob controls the beam focus and residual energy contamination. 13. The system of claim 11, wherein the at least one virtual knob controls an upstream electron suppression of the ion beam, preventing electrons from being stripped from the ion beam. 14. The system of claim 11, wherein the at least one virtual knob controls a deflection of the beam, and centers the beam at the exit of the lens. 15. The system of claim 14, further comprising instructions for measuring currents on inner and outer final ground electrodes of the plurality of electrode pairs, and centering the beam by varying beam deflection until the currents on the inner and outer final ground electrodes are equal. 16. The system of claim 14, further comprising instructions for providing a collimated light sensor vertically centered within an exit aperture of the lens to determine beam centering. 17. The system of claim 11, wherein the at least one virtual knob controls a final deflection angle of the ion beam and constrains the position of the ion beam at the exit of the lens. 18. The system of claim 11, wherein the step of grading a deceleration of the ion beam further comprises calculating the energy of the beam's central ray trajectory (CRT) along a length of the lens. 19. The system of claim 11, wherein electrode voltages are assigned to the upper and lower electrode pairs such that voltages of outer electrodes of the plurality of upper and lower electrode pairs remain negative.