A HEAVY ION FUSION DRIVER FINAL FOCUS SYSTEM

INERTIAL CONFINEMENT FUSION USING HEAVY ION DRIVERS IS A PROMISING TECHNIQUE TO OBTAIN COMMERCIAL FUSION ENERGY, PRIMARILY BECAUSE OF ITS HIGH EFFICIENCY, HIGH REPETITION RATES, AND THE GOOD RELIABILITY OF PARTICLE ACCELERATORS. THE VERY INTENSE, SHORT DURATION HEAVY ION BEAM PULSES FROM THE DRIVER MUST BE FOCUSED TO A VERY SMALL SPOT TO IGNITE A FUSION PELLET IN A REACTOR. CONSEQUENTLY, IT IS VERY IMPORTANT TO TAKE THE SPACE CHARGE OF THE BEAM INTO ACCOUNT WHEN DESIGNING A HEAVY ION DRIVER, PARTICULARLY IN THE BEAM TRANSPORT SYSTEM BETWEEN THE ACCELERATOR AND THE TARGET PELLET. MUCH THEORETICAL WORK HAS BEEN COMPLETED ON THE TRANSPORT AND FOCUSING OF THE HIGH CURRENT HEAVY ION BEAMS IN PROPOSED HEAVY ION DRIVER SYSTEMS. RECENT WORK AT LAWRENCE LIVERMORE NATIONAL LABORATORY (LLNL) ON THE TARGET CONFIGURATION FOR HEAVY ION FUSION HAS REVEALED THAT WHEN THE TARGET PELLET IS HIT BY THE HEAVY ION BEAMS, THE PELLET SURFACE BECOMES HOT. RADIATION EMITTED FROM THE HOT SURFACECAN PHOTOIONIZE THE LATTER PART OF THE BEAM PULSE, CAUSING IT TO LOSE FOCUS AND MISS THE TARGET PELLET. THIS DETAILED PHASE I STUDY, CONDUCTED IN COLLABORATION WITH LLNL, WILL DESIGN A BEAM TRANSPORT AND FINAL FOCUSING SYSTEM FOR A HEAVY ION DRIVER. THE DESIGN WILL INCORPORATE CORRECTIONS FOR THE TIME-DEPENDENT DEFOCUSING OF THE HEAVY ION BEAM AT THE FINAL FOCAL POINT CAUSED BY THE INCREASED SPACE CHARGE. THE SOLUTION WILL BE VERIFIED BY MULTIPARTICLE BEAM DYNAMICS SIMULATIONS; A SCALED PROOF-OF-PRINCIPLE EXPERIMENT WILL BE PERFORMED IN PHASE II.