Plasma And Electrical Diagnostics For Procyon Experiments

The aim of the Trailmaster series of experiments is to generate an intense source of soft x-rays by imploding a thin (2000 {Angstrom}) aluminum cylinder. The present scheme incorporates a plasma flow switch for the final pulse shaping and requires careful diagnostic analysis. The emphasis of this work is to transfer the energy to the load area and to understand the dynamics of the plasma flow switch. The experiments are carried out at LANL in two facilities. Laboratory experiments that answer questions about the details of the plasma flow switch are done on the 1.5-MJ Pegasus capacitor bank. The higher energy experiments (Procyon series) utilize explosive pulsed power systems and are conducted at the Ancho Canyon firing site. It is the latter set of experiments that will eventually supply an x-ray radiation source at the megajoule level. At the present time, the emphasis of the Procyon experiments is to deliver energy from the generator to the plasma flow switch and the load area. The details of these experiments are given in other papers at this conference. In order to characterize these experiments one needs to diagnose the driver performance and the dynamics of the plasma and power flow in the plasma flow switch region. The difficulty of experiments in which high current high voltage, and high explosive are combined, leads to severe problems. Many of the diagnostics are unique and untested. Since only a limited number of experiments are done during a year, the effort is to maximize the information per shot. The aim in this report is to present some of the diagnostic techniques used in the adverse Trailmaster environment. 8 refs., 10 figs

Procyon Experiments Utilizing Foil-fuse Opening Switches

The Los Alamos National Laboratory has applied the explosive magnetic flux compression generator (FCG) technology to the high-energy foil-implosion project, Trailmaster, to reach energy levels unattainable by other methods under current budget constraints. A required component for FCG systems is a power-conditioning stage that matches the slow risetime of the energy source with the fast-risetime requirements of the foil-implosion load. Currently, the Trailmaster concept is based on a two-step process of combining an intermediate power compression stage with a plasma flow switch (PFS) that will deliver energy to an imploding foil on the order of 100 ns. The intermediate power compression stage, which is the main emphasis of this report, consists of an energy storage inductor loaded by the FCG (the energy sauce) and an associated opening and closing switch. In our Procyon testing series, a subtask of the Trailmaster project, we have explored two approaches for opening and closing switches. One uses an explosive opening switch (EFF) and a detonator-initiated closing switch, the topic of another paper at this conference, and the other a resistive fuse opening switch a surface tracking closing switch (STS), the subject of this presentation. This latter concept was successfully tested last summer with a complete plasma flow switch assembly except the dynamic implosion foil was replaced by a rigid passive inductive load. We present data on the performance of the fuse opening switch, the surface tracking closing switch, and the plasma flow switch. 7 refs., 9 figs

Procyon Experiments Utilizing Explosively-formed Fuse Opening Switches

In this paper we describe results from tests of an explosive pulsed power system designed to deliver 15--16 MA to a plasma flow switch (PFS). The PFS, in turn, has the goal of switching current to a z- pinch load to produce a 1-MJ implosion for x-ray generation experiments. The system consists of a MK-IX magnetic flux-compression generator, a coaxial inductive store, an explosively formed fuse (EFF) opening switch, and a vacuum power flow/PFS assembly. Figure 1 shows a completed assembly ready to test. Computational modeling of this system is described in another paper in this conference, and important design considerations have been previously published. Vacuum diagnostics are also discussed in a separate paper in this conference as are results from a test in which a conventional foil-fuse opening switch replaced the EFF. We have performed two development tests of the Procyon system. A preliminary reduced energy test (Shot 1) delivered {approximately}13.6 MA to a 25-nH PFS load, and imposed a large voltage spike on the EFF at nominal pinch time without failure. In a full-energy test (Shot 2), the system delivered 20 MA to the EFF without suffering unexpected losses, and demonstrated the proper onset of EFF opening. In the 20-MA test, mistiming between the EFF and the load isolation switches led to transmission line failure that disguised late time opening switch performance and diverted most of the current pulse away from the PFS load. These two tests have provided important system characterization information. In some cases design expectations are confirmed and in others adjustments to initial expectations are called for. Performance details are presented below. 8 refs., 13 figs

Ranchero Explosive Pulsed Power Experiments

The authors are developing the Ranchero high explosive pulsed power (HEPP) system to power cylindrically imploding solid-density liners for hydrodynamics experiments. The near-term goal is to conduct experiments in the regime pertinent to the Atlas Capacitor bank. That is, they will attempt to implode liners of {approximately}50 g mass at velocities approaching 15 km/sec. The basic building block of the HEPP system is a coaxial generator with a 304.8 mm diameter stator, and an initial armature diameter of 152 mm. The armature is expanded by a high explosive (HE) charge detonated simultaneously along its axis. They have reported a variety of experiments conducted with generator modules 43 cm long and have presented an initial design for hydrodynamic liner experiments. In this paper they give a synopsis of their first system test, and a status report on the development of a generator module that is 1.4 m long