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We have calibrated the x ray response of a variable line spaced grating spectrometer, known as the VSG, at the Fusion and Astrophysics Data and Diagnostic Calibration Facility at the Lawrence Livermore National Laboratory (LLNL). The VSG has been developed to diagnose laser produced plasmas, such as those created at the Jupiter Laser Facility and the National Ignition Facility at LLNL, and at both the Omega and Omega EP lasers at University of Rochester's Laboratory for Laser Energetics. The bandwidth of the VSG spans the range from ~ 6 to 60 Å. The calibration results present here include the VSG's dispersion and quantum efficiency. The dispersion is determined by measuring the x rays emitted from hydrogen-like and helium-like ions of carbon, nitrogen, oxygen, neon, and aluminum. The quantum efficiency is calibrated to an accuracy of 30% or better by normalizing the x ray intensities recorded by the VSG to those simultaneously recorded by an x ray microcalorimeter spectrometer.

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A 2400 lines/mm variable-spaced grating spectrometer has been used to measure soft x-ray emission (8–22 Å) from laser-produced plasma experiments at Lawrence Livermore National Laboratory’s Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x rays emitted from the back of the Mylar and the copper foils irradiated at 1015 W/cm2. The instrument demonstrated a resolving power of ∼120 at 19 Å with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolutions of this diagnostic make it useful for studies of high temperature plasmas.

The soft x-ray imager (SXRI) built for the first experiments at the National Ignition Facility (NIF) has four soft x-ray channels and one hard x-ray channel. The SXRI is a snout that mounts to a four strip gated imager. This produces four soft x-ray images per strip, which can be separated in time by ∼60ps. Each soft x-ray channel consists of a mirror plus a filter. The diagnostic was used to study x-ray burnthrough of hot Hohlraum targets at the NIF and OMEGA lasers. The SXRI snout design and issues involved in selecting the desired soft x-ray channels are discussed.

Data produced by an electron beam ion trap (EBIT) can be crucial for interpreting spectra from plasmas created by long-pulse lasers. Four example spectra are considered: (i) the spectra from the hot gold plasma in the laser deposition region of a hot hohlraum, (ii) the He-β spectra from an argon-doped imploding core of an inertial confinement fusion capsule, (iii) the polarization in spectral lines produced by hot electrons generated by laser-plasma parametric instabilities, and (iv) the spectra of the underdense plasma from an aerogel X-ray source. The EBIT data needed for these cases are: (i) the line positions for 3 → 2 transitions in open M shell gold ions, (ii) the Li-like satellite lines for the K-β transition in open L shell argon ions, (iii) the polarization of suitable X-ray lines at 30 keV, and (iv) the precise wavelengths of K lines of highly charged Si ions and the precise wavelengths of L and K lines of highly charged Ge ions. Résumé :Les données produites par un piège ionique à faisceau d'électrons (EBIT) peuvent être très importantes pour interpréter les spectres dans les plasmas créés par de longues pulsations laser. Nous étudions quatre types de spectre : (i) le spectre d'un plasma d'or chaud dans la région de déposition d'un corps noir chaud, (ii) le spectre He-β du coeur dopé à l'argon en implosion d'une capsule de fusion par confinement inertiel, (iii) la polarisation dans les lignes spectrales produite par électrons chauds générés par les instabilités paramétriques d'un plasma laser, (iv) le spectre du plasma de faible densité d'une source de rayons-X en aérogel. Les données EBIT nécessaires à cette fin sont : (i) la position des lignes pour les transitions 3 → 2 dans les couches M ouvertes d'ions d'or, (ii) les lignes satellites de type Li pour la transition K-β dans les couches L ouvertes d'ions d'argon, (iii) la polarisation de lignes de rayons-X adéquates à 30 keV, (iv) les longueurs d'onde précises des lignes K d'ions Si fortement chargés et les longueurs d'onde précises des lignes L et K d'ions Ge hautement chargés.[Traduit par la Rédaction]

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(Presented XXXXX; received XXXXX; accepted XXXXX; published online XXXXX) The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10 -50 Å waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer (ECS). The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes and x-ray sources.