Self-emissionx-rayshadowgraphyprovidesamethodtomeasuretheablation-fronttrajectoryandlow-modenonuniformityofatargetimplodedbydirectlyilluminatingafusioncapsulewithlaserbeams.Thetechniqueusestime-resolvedimagesofsoftx-rays(>1keV)emittedfromthecoronalplasmaofthetargetimagedontoanx-rayframingcameratodeterminethepositionoftheablationfront.Methodsusedtoaccuratelymeasuretheablation-frontradius(δR=±1.15μm),image-to-imagetiming(δ(t)=±2.5ps)andabsolutetiming(δt=±10ps)arepresented.Angularaveragingoftheimagesprovidesanaverageradiusmeasurementofδ(Rav)=±0.15μmandanerrorinvelocityofδV/V=±3%.ThistechniquewasappliedontheOmegaLaserFacility[Boehlyetal.,Opt.Commun.133,495(1997)]andtheNationalIgnitionFacility[CampbellandHogan,PlasmaPhys.Control.Fusion41,B39(1999)].
