Liquid butane filled load for a liner driven Pegasus experiment

Summary form only given, as follows. A hydrogen rich, low density liquid, contained within the internal volume of a cylindrical liner, was requested of the Polymers and Coatings Group (MST-7) of the Los Alamos Materials Science Division for one of the last liner driven experiments conducted on the Los Alamos Pegasus facility. The experiment required massive tungsten glide planes for inertial confinement of the liner fill media during implosion. Shallow sinusoidal perturbations were machined on the inside surface of the liner to seed instabilities, also true of the previous experiments. Butane was selected for a relatively low equilibrium vapor pressure, a practical attribute for use in the Pegasus vacuum power flow channel. Butane safety topics at Pegasus will be addressed. Glide planes were sealed to the liner by use of butane compatible o-rings. A sintered form of tungsten was used for the glide planes to facilitate machining the relatively complex shapes that were required. Porosity of the tungsten was sealed by an epoxy vacuum/pressure impregnation procedure. Following some development experiments, we chose to prefill the load with butane and seal the liner assembly as opposed to filling the load while installed in the target chamber at Pegasus. A butane reservoir was developed and mounted above the load as a part of the load assembly to allow monitoring the liquid level and to prevent loss of the experiment as a result of possible butane loss during the few days required to set up a Pegasus experiment. This paper describes the load fabrication processes and development of novel procedures that were required. We expect to apply the technologies to future Los Alamos experiments that will be conducted at the new Atlas facility.