X-ray optics for Laboratory Astrophysics

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1 X-ray optics for Laboratory Astrophysics Abstract: One of the goals of the inertial confinement fusion program at the Lawrence Livermore National Laboratory is to achieve ignition through the indirect drive technique. One of the programs defined to achieve this objective involves an indirect drive approach which converts laser energy to X-rays via absorption by high-z material in a hohlraum which surrounds the target. Experiments are underway to measure the distribution and total power deposited in the hohlraum. Several X-ray diagnostics have been implemented at NIF to accomplish this, including pinhole camera diagnostics. We are proposing to build Wolter optics to improve the collection efficiency by orders of magnitude over diagnostics currently in use. The high density, high temperature plasmas reached at the NIF also provide an opportunity to study hydrodynamic and radiative properties found in astrophysical sources such as stellar interiors and supernovae. These studies are included in the NIF Basic Science Program, and our proposed diagnostics would help enable these investigations. Collaborators: Mike Pivovaroff (LLNL), Brian Ramsey (MSFC)

2 X-ray optics for Laboratory Astrophysics OUR Goal : build Wolter X-optics to improve the collection efficiency by at least an order of magnitude over current diagnostic tools -- $$ funding to continue to advance the technology NIF Goal : to achieve ignition through the indirect drive technique. Experiments are underway (at NIF) to measure the distribution and total power deposited in the target Opportunity exists: These studies present a unique opportunity to study physics in regimes (e.g. high density plasmas) important in astrophysical sources such as stellar interiors, supernova, etc.

3 Grazing Incidence X-ray optics One slide tutorial collection efficiency

4 Hard X-ray telescope prototype Fabricated by: SAO, MSFC, OAB 60 cm We have ongoing program to develop/ fabricate X-ray optics for future X-ray missions. Supported by: NASA/ROSES, NASA/SBIR, DOE

5 Optic for astronomical X-ray telescope 42 cm Optic for laboratory astrophysics 50 x 30 mm

6 Schematic of NIF diagnostic V~1kV Array of pinholes produces many images, gated at different times- about f/10,000 Imploding NIF X-ray optic 2 orders of mag improved Collection efficiency over pinholes

7 Must fit into existing design Source 10x 5 mm Optic Detector 2.4 m 50 x 30 mm Hohlraum For indirect drive by properly tailoring the multilayer design/coating of optic, can provide very precise spectral filtering for high spatial resolution, narrow spectral band, hard X-ray optic (e.g., a multilayer-coated Wolter imager

8 A tour of some of the NIF Diagnostics 10 m diameter NIF ppt Kilkenny - NIF Diagnostics Discussion, Jan. 30, 2012 LLNL-PRES

9 Hohlraum Blue => laser beams (LLNL utube) video

10 Lasers enter Hohlraum X-rays created Implosion of target - Self-sustained fusion reaction

11 schematic of the target and laser beams used to study the energetics and drive symmetry of the Hohlraum design Goal: Achieve Ignition through the in-direct drive technique Schneider et al. Rev Sci Inst 2010

12 X-ray Imager Diagnostic by properly tailoring the multilayer design/coating of optic, can provide very precise spectral filtering for high spatial resolution, narrow spectral band, hard X-ray optic (e.g., a multilayer-coated Wolter imager Images from this tool provide info on backlit size of the LEH the positions and intensities of the laser beams interacting with the high-z plasma of the wall this info is used to: compared with models to understand the energy coupled to the capsule Determinine whether Hohlraum performance is consistent with requirements for ignition.

13 Wolter optics (fabricated at SAO, MSFC) could improve the collection efficiency by orders of magnitude over pinhole diagnostics currently in use. **Opportunity exists**: to study physics in regimes (e.g. high density plasmas) important in astrophysical sources such as stellar interiors, supernova, etc.