A novel x-ray diagnostic of laser-fusion plasmas is described, allowing 2D monochromatic images of hot, dense plasmas to be obtained in any x-ray photon energy range, over a large domain, on a single-shot basis. The device (named energy-encoded pinhole camera) is based upon the use of an array of many pinholes coupled to a large area CCD camera operating in the single-photon mode. The available x-ray spectral domain is only limited by the quantum efficiency of scientific-grade x-ray CCD cameras, thus extending from a few keV up to a few tens of keV. Spectral 2D images of the emitting plasma can be obtained at any x-ray photon energy provided that a sufficient number of photons had been collected at the desired energy. Results from recent inertial confinement fusion related experiments will be reported in order to detail the new diagnostic.
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http://dx.doi.org/10.1063/1.4759135 | DOI Listing |
Soft Matter
January 2025
College of Chemistry, Sichuan University, Chengdu 610064, China.
Biomolecules usually adopt ubiquitous circular structures which are important for their functionality. Based on three-dimensional Langevin dynamics simulations, we investigate the conformational change of a polymer confined in a spherical cavity. Both passive and active polymers with either homogeneous or heterogeneous stiffness are analyzed in a comparative manner.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China.
In inertial confinement fusion experiments, hot spot mix caused by hydrodynamic instabilities is a critical performance limitation. Currently, multi-channel Ross filter pair imaging is used to quantitatively diagnose the mix mass of cryogenic hot spots driven by 100 kJ energy, but this method brings significant uncertainty. To measure the level of mix more accurately, we have developed a two-temperature model to modify the fitted bremsstrahlung spectra based on the characteristics of cryogenic implosion hot spots.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
The energy cascade, i.e. the transfer of kinetic energy from large-scale to small-scale flow motions, has been the cornerstone of turbulence theories and models since the 1940s.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
Key Laboratory for Laser Plasmas and Department of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China; Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China. Electronic address:
Although ignition had been achieved at the National Ignition Facility (NIF), recent observations of the experiments indicate novel physics that beyond theoretical predictions emerge, e.g., the neutron analysis of experiments has revealed deviations from the Maxwellian distributions in ion relative kinetic energies of burning plasmas, with the surprising emergence of supra-thermal deuterium and tritium (DT) ions that fall outside the predictions of macroscopic statistical hydrodynamic models.
View Article and Find Full Text PDFPhys Rev E
November 2024
Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
Diffusion-dominated mix in inertial confinement fusion (ICF) is characterized where the majority of the mix occurs in the immediate fuel-shell interface while hydrodynamic-dominated mix pulls shell material from farther away into the central fuel. A thin (150 nm) separated reactants ICF mix platform is highly sensitive to the amount of mix from the first micron of shell-fuel interface. This fine-spatial resolution platform has revealed that material mix in moderate convergence (CR∼12) ICF implosions is dominated by a diffusion mechanism.
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