MACH2 simulations of the DECADE plasma opening switch

Summary form only given. The DECADE nuclear effects simulator at the Arnold Engineering Development Center (AEDC) uses a plasma opening switch (POS) to create a high voltage pulse used for a bremsstrahlung X-ray diode. AEDC has supported a modeling effort for the past several years at the University of Tennessee Space Institute (UTSI) in which the MACH2 computer code has been used to make numerical simulations of the POS and the cableguns used to initiate the switch. It was found that the Hall effect played an important role in the opening of the switch, but simulations predicted that current progressed along the cathode prior to the anode, in contrast to measurements obtained with B-dot probes. Some interferometer measurements presented at a DECADE review meeting in 1998 indicated that a higher density plasma layer approximately one millimeter thick formed on the electrode surfaces.