Source geometric considerations for OMEGA Dante measurements

Journal Article · Mon Oct 01 04:00:00 EDT 2012 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4734041· OSTI ID:1226204

May, M. J.; Patterson, J. R.; Sorce, C.; Widmann, K.; Fournier, K. B.; Perez, F.

The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or “hot spots” in the x-ray are observed where the drive laser beams strike the target. The “hot spots” create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C22H10N2O5) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2–3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1226204
• Report Number(s): LLNL-JRNL--554314
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 83; ISSN 0034-6748
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS