Soft x-ray images of the laser entrance hole of ignition hohlraums

Journal Article · Mon Oct 15 04:00:00 EDT 2012 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4732850· OSTI ID:22093963

Schneider, M. B.; Meezan, N. B.; Alvarez, S. S.; Alameda, J.; Baker, S.; Bell, P. M.; Bradley, D. K.; Callahan, D. A.; Celeste, J. R.; Dewald, E. L.; Dixit, S. N.; Doeppner, T.; Eder, D. C.; Edwards, M. J.; Fernandez-Perea, M.; Hau-Riege, S.; Hsing, W.; Izumi, N.; Jones, O. S.; Kalantar, D. H. ^[1] ; others, and

---

1. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States)

Hohlraums are employed at the national ignition facility to convert laser energy into a thermal x-radiation drive, which implodes a fusion capsule, thus compressing the fuel. The x-radiation drive is measured with a low spectral resolution, time-resolved x-ray spectrometer, which views the region around the hohlraum's laser entrance hole. This measurement has no spatial resolution. To convert this to the drive inside the hohlraum, the size of the hohlraum's opening ('clear aperture') and fraction of the measured x-radiation, which comes from this opening, must be known. The size of the clear aperture is measured with the time integrated static x-ray imager (SXI). A soft x-ray imaging channel has been added to the SXI to measure the fraction of x-radiation emitted from inside the clear aperture. A multilayer mirror plus filter selects an x-ray band centered at 870 eV, near the peak of the x-ray spectrum of a 300 eV blackbody. Results from this channel and corrections to the x-radiation drive are discussed.

• OSTI ID: 22093963
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 83; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
APERTURES
CORRECTIONS
FILTERS
IGNITION
LASER RADIATION
LAYERS
MIRRORS
SOFT X RADIATION
SPATIAL RESOLUTION
TIME RESOLUTION
US NATIONAL IGNITION FACILITY
X-RAY SPECTRA
X-RAY SPECTROMETERS