title: Temperature measurements of shocked silica aerogel foam.
abstract: We present recent results of equation-of-state (EOS) measurements of shocked silica (SiO_{2}) aerogel foam at the OMEGA laser facility. Silica aerogel is an important low-density pressure standard used in many high energy density experiments, including the novel technique of shock and release. Due to its many applications, it has been a heavily studied material and has a well-known Hugoniot curve. This work then complements the velocity and pressure measurements with additional temperature data providing the full EOS information within the warm dense matter regime for the temperature interval of 1-15 eV and shock velocities between 10 and 40 km/s corresponding to shock pressures of 0.3-2 Mbar. The experimental results were compared with hydrodynamic simulations and EOS models. We found that the measured temperature was systematically lower than suggested by theoretical calculations. Simulations provide a possible explanation that the emission measured by optical pyrometry comes from a radiative precursor rather than from the shock front, which could have important implications for such measurements.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: K
authors.initials: K
authors.lastname: Falk
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: McCoy
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Fryer
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Greeff
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Hungerford
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Montgomery
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Schmidt
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Sheppard
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Williams
authors.affiliation: Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Boehly
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Benage
mesh_terms: D005782:Gels; D007368:Interferometry; D007834:Lasers; D008422:Materials Testing; D011312:Pressure; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature
chemical_list: D005782:Gels; D012822:Silicon Dioxide