Precision Intense Particle Beam Accelerators Using in-Situ Tuning Techniques

Modern superpower accelerators are capable of up to 15 MeV and over 10 TW in 100ns pulses using oil or water insulated pulselines. Previous pulseline accelerators have generally had to accept a pulse shape somewhat different than the design based on computer simulation (due to unpredictable load dynamics in many cases). This paper presents an iterative perturbation theory approach to accelerator design. The approach utilizes a transmission line whose taper can be adjusted in-situ, thereby permitting corrections to the voltage waveform during operation with the actual dynamic particle beam load. Two successful examples of this iterative perturbation theory approach are: (1) the achievement of a ramped voltage pulse to bunch a light ion beam ICF driver. The ORCA-I 1 MeV - 200ns accelerator with ± 1% precision has been tested and is now used in low emittance light ion beam ICF driver research, (2) the suppression of voltage droop in a field emission diode with plasma induced gap closure. A precise (± 1%) voltage plateau is achieved for use in high rep-rate generators for pre-ionizing high energy gas laser chambers.