Matter in Extreme Conditions Instrument - Conceptual Design Report

[摘要] The SLAC National Accelerator Laboratory (SLAC), in collaboration with Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL), and the University of California at Los Angeles (UCLA), is constructing a Free-Electron Laser (FEL) research facility. The FEL has already met its performance goals in the wavelength range 1.5 nm - 0.15 nm. This facility, the Linac Coherent Light Source (LCLS), utilizes the SLAC 2-Mile Linear Accelerator (linac) and will produce sub-picosecond pulses of short wavelength X-rays with very high peak brightness and almost complete transverse coherence. The final one-third of the SLAC linac is used as the source of electrons for the LCLS. The high energy electrons are transported across the SLAC Research Yard, into a tunnel which houses a long undulator. In passing through the undulator, the electrons are bunched by the force of their own synchrotron radiation and produce an intense, monochromatic, spatially coherent beam of X-rays. By varying the electron energy, the FEL X-ray wavelength is tunable from 1.5 nm to 0.15 nm. The LCLS includes two experimental halls as well as X-ray optics and infrastructure necessary to create a facility that can be developed for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of designing and constructing an X-ray instrument in order to exploit the unique scientific capability of LCLS by creating extreme conditions and study the behavior of plasma under those controlled conditions. This instrument will address the Office of Science, Fusion Energy Sciences, mission objective related to study of Plasma and Warm Dense Matter as described in the report titled LCLS, the First Experiments, prepared by the LCLS Scientific Advisory Committee (SAC) in September 2000. The technical objective of the LCLS Matter in Extreme Conditions (MEC) Instrument project is to design, build, and install at the LCLS an X-ray instrument that will complement the initial instrument suite included in the LCLS construction and the LUSI Major Item of Equipment (MIE) Instruments. As the science programs advance and new technological challenges appear, instrumentation must be developed and ready to conquer these new opportunities. The MEC concept has been developed in close consultation with the scientific community through a series of workshops team meetings and focused reviews. In particular, the MEC instrument has been identified as meeting one of the most urgent needs of the scientific community based on the advice of the LCLS Scientific Advisory Committee (SAC) in response to an open call for letters of intent (LOI) from the breadth of the scientific community. The primary purpose of the MEC instrument is to create High Energy Density (HED) matter and measure its physical properties. There are three primary elements of the MEC instrument: (A) Optical laser drivers that will create HED states by irradiation in several ways and provide diagnostics capability; (B) The LCLS x-ray free electron laser, which will provide the unique capability to create, probe and selectively pump HED states; and, (C) A suite of diagnostic devices required to observe the evolution of the HED state. These elements when combined in the MEC instrument meet the 'Mission Need' as defined in CD-0. For the purposes of the description we separate the types of experiments to be performed into three categories: (1) High pressure: Here we are interested in the generation of high pressure using the optical lasers to irradiate a surface that ablates and drives a pressure wave into a sample, similar to a piston. The pressures that can be reached exceed 1 Mbar and the properties of interest are for example, the reflectivity, conductivity, opacity as well as the changes driven by the pressure wave on, e.g., condensed matter structure. These phenomena will be studied by means of diffraction measurements, measurements of the pressure wave characteristics, in situ probing by x-ray scattering of various types all time resolved. The necessary diagnostics are discussed.

[发布日期] 2009-12-09

[学科分类] 核物理和高能物理

[关键词] ATOMIC PHYSICS;COMPTON EFFECT;DESIGN;DISTRIBUTION FUNCTIONS;ELECTRONS;ENERGY DENSITY;ENERGY SPECTRA;FERMILAB ACCELERATOR;FREE ELECTRON LASERS;INERTIAL CONFINEMENT;LASERS;LIGHT SOURCES;LINEAR ACCELERATORS;PARTICLE BEAMS;PHASE SPACE;PHYSICAL PROPERTIES;SAFETY REPORTS;SCATTERING;SYNCHROTRON RADIATION;THERMONUCLEAR REACTORS;X-RAY SOURCES;X-RAY SPECTROMETERS Instrumentation;OTHER