Publications

Rose, Charles; Whetten, Shaun R.; Mahaffey, Jacob T.; Simpson, Sean S.; Saiz, David J.; Puckett, Raymond V.

Stockpile stewardship requires accurate and predictive models relying on the generation of extreme environments which is both incredibly difficult and profoundly necessary. Next generation pulsed power facilities (NGPPF), where these environments are created, may require a paradigm shift in equipment engineering/manufacture to fulfill this need. Therefore, this research aims to investigate the limitations, capabilities and efficacy of leveraging advancements in the field of additive manufacturing (AM) in order to produce novel power flow components for NGPPFs. This work focused on commercial 3D metal AM equipment producing several prototypes addressing prescient needs/shortcomings, and a technique wherein a lightweight polymer core is metalized. Ultimately, commercial 3D metal AM is considered a viable path forward but would require a sizeable investment and does not currently support the scale and complexity necessary for NGPPFs. Moreover, initial results from our composite technique are promising and is considered a realizable path forward given further investigation.

Simpson, Sean S.; Rose, Charles; Mourning, Ronald L.; Johns, Owen J.

Abstract not provided.

AIAA Aviation 2019 Forum

Rose, Charles; Yalin, Azer P.; Simpson, Sean S.; Patel, Sonal P.

We present the setup and preliminary diagnostic measurements of an optically accessible high-voltage laser trigger switch (HV-LTS) operating with zero air and millimeter gap lengths. The switch is utilized as a test bed to collect electrical and optical measurements to inform recently discovered gaps in the Tom Martin switch model. We present the basic theory of this model including key assumptions on the radial plasma channel growth and constant electrical conductivity. Characteristic electrical measurements of the switch are presented including: self-break curve, minimum laser energy to trigger with ~100% reliability for various set voltages, and equivalent circuit resistance and inductance. Schlieren images are presented of the temporal blast wave associated with laser triggering, as well as switch closure plasma. Radial plasma growth is measured and found to agree with the Martin model assumptions, albeit with variability yielding a potential error in calculated resistance of ~15%. Optical emission spectra of switch closure are also recorded and show the spectra to be dominated by continuum at early times with emission lines becoming visible at ~200 ns after a 25 kV shot and ~500 ns after a 100 kV shot. This data, to the best of the author’s knowledge, represents the first publication of HV-LTS emission spectra.