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Title: Calibration of the OHREX high-resolution imaging crystal spectrometer at the Livermore electron beam ion traps [Calibration of the OHREX high-resolution imaging crystal spectrometer at the Livermore EBIT]

Here, we report the calibration of the Orion High-Resolution X-ray (OHREX) imaging crystal spectrometer at the EBIT-I electron beam ion trap at Livermore. Two such instruments, dubbed OHREX-1 and OHREX-2, are fielded for plasma diagnostics at the Orion laser facility in the United Kingdom. The OHREX spectrometer can simultaneously house two spherically bent crystals with a radius of curvature of r=67.2 cm. The focusing properties of the spectrometer allow both for larger distance to the source due to the increase in collected light and for observation of extended sources. OHREX is designed to cover a 2.5–3 degree spectral range at Bragg angles around 51.3 degree. The typically high resolving powers at these large Bragg angles are ideally suited for line shape diagnostics. For instance, the nominal resolving power of the instrument (> 10000) is much higher than the effective resolving power associated with the Doppler broadening due to the temperature of the trapped ions in EBIT-I. The effective resolving power is only around 3000 at typical EBIT-I conditions, which nevertheless is sufficient to set up and test the instrument’s spectral characteristics. We have calibrated the spectral range for a number of crystals using well known reference lines in first andmore » second order, and derived the ion temperatures from these lines. We have also made use of the 50µm size of the EBIT-I source width to characterize the spatial focusing of the spectrometer.« less
ORCiD logo [1] ; ORCiD logo [2] ;  [2] ;  [2]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. Erlangen-Nurnberg, Bamberg (Germany)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0034-6748; RSINAK
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 87; Journal Issue: 11; Conference: Proceedings of the 21st Topical Conference on High Temperature Plasma Diagnostics, Madison, WI (United States), 5-9 Jun 2016; Journal ID: ISSN 0034-6748
American Institute of Physics (AIP)
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
Country of Publication:
United States
OSTI Identifier: