Absolute radiant power measurement for the Au M lines of laser-plasma using a calibrated broadband soft X-ray spectrometer with flat-spectral response

Abstract

CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX on the Omega laser facility at the Laboratory for Laser Energetics (LLE) in 1999 to measure radiant power and spectral distribution of the radiation of the Au plasma. The DMX spectrometer is composed of 20 channels covering the spectral range from 50 eV to 20 keV. The channels for energies below 1.5 keV combine a mirror and a filter with a coaxial photo-emissive detector. For the channels above 5 keV the photoemissive detector is replaced by a conductive detector. The intermediate energy channels (1.5 keV < photon energy < 5 keV) use only a filter and a coaxial detector. A further improvement of DMX consists in flat-response X-ray channels for a precise absolute measurement of the photon flux in the photon energy range from 0.1 keV to 6 keV. Such channels are equipped with a filter, a Multilayer Mirror (MLM), and a coaxial detector. We present as an example the development of channel for the gold M emission lines in the photon energy range from 2 keV to 4 keV which has been successfully used on the OMEGA laser facility. The results of the radiant power measurements with the new MLM channel and with the usual channel composed of a thin titanium filter and a coaxial detector (without mirror) are compared. All elements of the channel have been calibrated in the laboratory of the Physikalisch-Technische Bundesanstalt, Germany's National Metrology Institute, at the synchrotron radiation facility BESSY II in Berlin using dedicated well established and validated methods.

Turbulent hydrodynamics experiments in high energy density plasmas: scientific case and preliminary results of the TurboHEDP project

“…The upper quadruplets irradiate the faceon (blue beams in Figure 9(b)) and the side-on backlighter foils. At that moment, the main diagnostic considered is the enhanced resolution hard X-ray imager (ERHXI) [78] inserted in the polar north inserter. The side-on radiography will provide information about shock planarity, deceleration and 2D density maps of the turbulent mixing zone.…”

X-ray broadband Ni/SiC multilayers: improvement with W barrier layers

“…Particularly, CEA implemented an absolutely calibrated broadband soft X-ray spectrometer called DMX [34]. A new channel of this spectrometer is developed for the 4 -6 keV range and follows another study already made for the 2 -4 keV channel [9,10].This channel is composed of a 10 µm Fe filter, a multilayer mirror (MIM) and a photoelectric coaxial detector. The MIM is optimized to be used at 1.3° grazing incidence angle.…”

“…The emergence of new sources and applications in the EUV and X-ray spectral domains raises more stringent requirements on the quality of multilayer mirrors. There is a real need for multilayers with low roughness and well-controlled interfaces for the design of complex components, such as ultra-short-period multilayers [1][2][3], alternate multilayer gratings [4], EUV broadband mirrors [5] and phase controlled mirrors for attosecond pulses [6], aperiodic broadband mirrors for X-ray optics [7,8] or plasma diagnostics [9,10]. It is well known that interface defects and material chemical stability often limit the theoretical efficiency of such mirrors.…”