Performance of the hermes-III pulse forming lines

Abstract

Hermes III is a new 20-MV, 730-kA, 40-ns pulsed power accelerator. In Hermes III, eighty pulse forming lines (PFLs) generate 1.1-MV, 220-kA pulses, which are then added in a series/parallel configuration to produce the desired output pulse. Under normal Hermes-III operation, the PFLs produce a /spl tilde/40-ns FWHM pulse with a /spl tilde/15-ns, 10-90% rise time, and a one-sigma jitter of /spl tilde/4 ns. The Hermes-III water-dielectric PFLs have undergone 18 months of testing. During this period, over 59,000 PFL-shots have been accumulated, most of these at or near peak power. The PFLs have met design specifications, and they have proven to be highly reliable. This paper presents a brief overview of the PFL design, together with a detailed discussion of the system performance and limitations during this extensive testing period. A modification to the PFLs to produce a ramped output pulse was designed and tested. Results indicate that a ramped output pulse can be produced using a stepped impedance PFL.