Soft x-ray images of the Laser Entrance Hole of NIC Hohlraums (paper, HTPD2012)

Conference · Mon Apr 30 04:00:00 EDT 2012

OSTI ID:1043636

Schneider, M B; Meezan, N B

Hohlraums at the National Ignition Facility convert laser energy into a thermal x-radiation drive, which implodes the capsule, thus compressing the fuel. The x-radiation drive is measured with a low resolution, time-resolved x-ray spectrometer that views the hohlraum's laser entrance hole (LEH) at 37{sup o} to the hohlraum axis. This measurement has no spatial resolution. To convert this to the drive inside the hohlraum, the area and fraction of the measured x-radiation which comes from the region inside the hohlraum must be known. The size of the LEH is measured with the time integrated Static X-ray Imager (SXI) which view the LEH at 18{sup o} to the hohlraum axis. A soft x-ray image has been added to the SXI to measure the fraction of x-radiation inside the LEH's Clear Aperture in order to correct the measured radiation. A multilayer mirror plus filter selects an x-ray band centered at 870 eV, near the x-ray energy peak of a 300 eV blackbody. Results from this channel and corrections to the x-radiation drive are discussed.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 1043636
• Report Number(s): LLNL-CONF-555011
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
APERTURES
LASERS
MIRRORS
PLASMA DIAGNOSTICS
RESOLUTION
SPATIAL RESOLUTION
US NATIONAL IGNITION FACILITY
X RADIATION
X-RAY SPECTROMETERS