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Real-Life Pulse Flattening on the LLNL Flash X-Ray (FXR) Machine.

DE2007910213

Publication Date	2007
Personal Author	DeHope, W. J.; Jacob, J. S.; Kihara, R.; Ong, M. M.; Zentler, J. M.
Page Count	5
Abstract	High-resolution radiography using high-current electron accelerators based on the linear induction accelerator principle requires the linacs final spot on the X-ray target to be millimeter-sized. The requisite final focusing solenoid is adjusted for a specific beam energy at its entrance, hence, temporal variation of entrance beam energy results in a less than optimal time-averaged spot size. The FXR (Flash X-Ray) induction linac facility at Lawrence Livermore National Laboratory will be briefly described with an emphasis on its pulsed power system. In principle, the pulsed Blumleins at the heart of the system output a square pulse when discharged at the peak of their charging waveform so that, with correct cell timing synchronization, the effective beam output into the final focusing solenoid should be optimally flat. We have found that real-life consideration of transmission line and pulse power details in both the injector and accelerator sections of the machine results in significant energy variations in the final beam. We have implemented methods of measurement and analysis that permits this situation to be quantified and improved upon. The improvement will be linked to final beam spot size and enhancement in expected radiographic resolution.
Keywords	Linear accelerators Radiography Pulsed power systems Particle Accelerators Test procedures Pulses Radiographs Estimating High-current electron accelerators Pulse flattening Flash X-ray accelerator (FXR) Lawrence Livermore National Laboratory (LLNL)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200725

Real-Life Pulse Flattening on the LLNL Flash X-Ray (FXR) Machine.

Real-Life Pulse Flattening on the LLNL Flash X-Ray (FXR) Machine.
DE2007910213

Publication Date	2007
Personal Author	DeHope, W. J.; Jacob, J. S.; Kihara, R.; Ong, M. M.; Zentler, J. M.
Page Count	5
Abstract	High-resolution radiography using high-current electron accelerators based on the linear induction accelerator principle requires the linacs final spot on the X-ray target to be millimeter-sized. The requisite final focusing solenoid is adjusted for a specific beam energy at its entrance, hence, temporal variation of entrance beam energy results in a less than optimal time-averaged spot size. The FXR (Flash X-Ray) induction linac facility at Lawrence Livermore National Laboratory will be briefly described with an emphasis on its pulsed power system. In principle, the pulsed Blumleins at the heart of the system output a square pulse when discharged at the peak of their charging waveform so that, with correct cell timing synchronization, the effective beam output into the final focusing solenoid should be optimally flat. We have found that real-life consideration of transmission line and pulse power details in both the injector and accelerator sections of the machine results in significant energy variations in the final beam. We have implemented methods of measurement and analysis that permits this situation to be quantified and improved upon. The improvement will be linked to final beam spot size and enhancement in expected radiographic resolution.
Keywords	Linear accelerators Radiography Pulsed power systems Particle Accelerators Test procedures Pulses Radiographs Estimating High-current electron accelerators Pulse flattening Flash X-ray accelerator (FXR) Lawrence Livermore National Laboratory (LLNL)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200725