A Unique U.S. Approach for Accelerator-Driven Warm Dense Matter Research--Preliminary Report

Logan, B G ; Davidson, R C ; Barnard, J J ; Lee, R

Lawrence Livermore National Laboratory

关键词: Compression;    75 Condensed Matter Physics, Superconductivity And Superfluidity;    70 Plasma Physics And Fusion Technology;    Chemical Explosives;    43 Particle Accelerators;   

DOI  :  10.2172/15015185
RP-ID  :  UCRL-TR-208767
RP-ID  :  W-7405-ENG-48
RP-ID  :  15015185

美国|英语

来源: UNT Digital Library

【 摘 要 】

The warm density matter regime of high energy density physics [1, 2, 3] has a high scientific discovery potential for the properties of plasmas at high densities and pressures and at moderate temperatures (kT) in which the Coulomb interaction energy between plasma particles exceed kT. This leads to correlations in the plasma characterized by the dimensionless ''coupling'' parameter {Lambda} > 1, where {Lambda} is defined by {Lambda} = q{sup 2}n{sup 1/3}/kT. Here q is the effective ion charge and n the ion density. Strongly-coupled plasmas with {Lambda} > 1 are difficult to study analytically and by numerical simulation. Many astrophysical systems (e.g., brown dwarfs, and giant planets) and inertial fusion plasmas in the beginning stages of compression fall into this regime. There is an opportunity to develop improved understanding and models through accurate measurements of properties in the large parameter space of temperature and density where data is currently limited or non-existent. X-ray free-electron lasers (Fourth generation light sources), ultra-short pulse and high energy optical lasers, pulsed-power z-pinch x-ray sources, and high explosives are all capable of producing warm dense matter conditions at various temperatures, pressures, and sample sizes. Therefore, the challenge is not how to create warm dense matter conditions, but to create it so that it's fundamental properties can be best studied. The goal is to advance this field of science through a variety of complementary facilities and methods which offer several combinations of desirable attributes: Precise control and uniformity of energy deposition; Large sample sizes compared to diagnostic resolution volumes; A benign environment for diagnostics (low debris and radiation background); High shot rates (10/hour to 1/second) and multiple beamlines/target chambers; and Sites with easy access for broad participation by university scientists and students; and with the technical support for designing and fielding targets for qualified experiments.