A high-current low-inductance vacuum spark was operated to produce hot
micropinches in copper plasmas. In order to improve the reproducibili
ty of the intense hard x-ray emission, different trigger modes and ano
de shapes were investigated. Based on the standard configuration used
in many vacuum spark set-ups, the temporal jitter was reduced by a fac
tor of eight while the spatial reproducibility of the plasma points wa
s improved by a factor of three.