Upgrades to the LLNL flash X-ray induction linear accelerator (FXR)

Abstract

DECLNMER UPGRADES TO THE LLNL FLASH X-RAY INDUCTION LINEAR ACCELERATOR (FXR)The FXR is an induction linear acceleratorused for flash radiography at the Lawrence Livtmnore National Laboratory's Site 300 Test Facility. The FXR was originally completedin 1982and has been in continuoususe as a radiographictool. At that time the FXR produceda 17MeV, 2.2 kA burst of electronsfor a duration of 65 ns.An upgrade of the FXR was recentl completed. The purpose of this upgrade was to improve the performanceof the FXl by increasing the energy of the electron injector from 1.2 MeV to 2.5 MeV and the beam current from 2.2 kA to 3 kA, improving the magnetictransport system by redesigningthe solenoidaltransport fms coils, reducing the rf coupling of the electron beam to the accelerator cells, and by adding additional beam d@OStiC&We will desmibethe injectur upgradesand pdbrmanc~as well as our effbrts to tune the acceleratorby~g beam corkscrew motion and the impact of Beam Breakup Instabilityon beam centroidmotionthroughoutthe beam line as the currentis increasedto 3 kA.

FXR Optimization Project: Determining Beam Quality By Cathode Plasma Image Analysis

“…For radiographic machines the figure of merit (FOM) for performance is described as x-ray dose divided by spot size. Upgrades have included improved transport magnets 3 , redesign of the injector 4 , impedance damping of the accelerator cells 5 , novel magnetic transport techniques 6 , improved pulsed power timing 7 , and a new cathode configuration 8 . These upgrades primarily improved spot size by minimizing the transverse motion of the beam.…”

Flash X-Ray (FXR) Accelerator Optimization Electronic Time-Resolved Measurement of X-Ray Source Size

“…The x-ray dose at 1 m is over 400 Rad with a final-focus spot-size of roughly 2.4 mm FWHM (full-width half-maximum) at the Tantalum bremsstrahlung target [1].…”

High power electron diode for linear induction accelerator at a flash radiographic facility

“…X-ray flash radiography is a powerful diagnostic used worldwide [1][2][3][4][5][6] for investigating the structural response of matter under impulsive loading during hydrodynamic experiments. Intense pulsed x-ray sources are required for capturing target motion during these experiments and, hence, obtaining good quality images.…”