Isentropic compression experiments to 1 Mbar using magnetic pressure

Abstract

Isentropic compression experiments that utilize intense magnetic fields to compress samples have been designed, developed and performed. The technique has been shown to work to pressures of more than 1 Mbar on Sandia National Laboratory's Z pulsed power machine. We are extending the technique to use high-explosive pulsed power.

Ramp wave loading experiments driven by heavy ion beams: A feasibility study

“…Most prominent are shock wave experiments (McQueen et al, 1983;Neal, 1976;Collins et al, 2001;Knudson et al, 2003;Fortov et al, 2007) but other techniques can explore different regions in phase space (see, e.g., Weir et al, 1959;Jayarama, 1986;Bakshi et al, 2009). Quasi-isentropic compression using ramp wave loading (RWL) (Reisman et al, 2000;Hayes, 2001;Cauble et al, 2002;Hayes et al, 2004;Rothman et al, 2005;Davis, 2006;Chhabildas & Barker, 1986;Barnes et al, 1974;Lorenz et al, 2004Lorenz et al, , 2005Smith et al, 2007;Swift & Johnson, 2005) allows sampling EOS data along an isentrope up to several Mbar pressures, located on the phase diagram between the parameter regions accessible with diamond anvil cells (Weir et al, 1959;Jarayama, 1986) and shock wave experiments (McQueen et al, 1983;Neal, 1976). Unlike a shock wave experiment where a single point on a shock adiabat is obtained, in RWL experiments, a continuous set of data points is recorded and the solid state of a sample is ensured up to high pressures.…”

“…The RWL method was also shown to be a more sensitive tool for studying the dynamics of the ultrafast structural phase transformations than the shock-wave based methods (Smith et al, 2008;Bastea et al, 2005;Dolan et al, 2007). RWL has been demonstrated with different drivers such as magnetic pulse loading using high-current pulsed power generators with typical loading times of 100 ns (Reisman et al, 2000;Hayes, 2001;Cauble et al, 2002;Hayes et al, 2004;Rothman et al, 2005;Davis, 2006), gas guns (Chhabildas & Barker, 1986) and high explosives (Barnes et al, 1974), with graded density impactors (1 ms) and highpower lasers (10 ms) (Lorenz et al, 2004(Lorenz et al, , 2005Swift & Johnson, 2005;Smith et al, 2007). On the other hand, intense heavy ion beams are an excellent tool to create high energy density in matter Tahir et al, 2005).…”

Accessing High Pressure States Relevant to Core Conditions in the Giant Planets

“…We have successfully demonstrated this laser-based technique for generating a high pressure ramped load at the Omega laser over a range of pressures spanning P max = 0.1 -2 Mbar. [Edwards, 2004;Lorenz, 2004 [Reisman, 2001;Hall, 2001;Cauble, 2002] In Fig. 3 we show the results from simulations of the design illustrated in Fig.…”