Since the first experimental campaign conducted in 2014 with mid field Gated X-ray Imager (GXI) and two quadruplets
(20 kJ at 351 nm) focused on target, the Laser MégaJoule (LMJ) operational capability is still growing up. New plasma
diagnostics have been implemented: a large field 2D GXI, two broadband x-ray spectrometers (called DMX and
miniDMX), a specific soft x-ray spectrometer and a Laser Entrance Hole (LEH) imaging diagnostic. A series of
experiments have been performed leading to more than 60 shots on target. We will present the plasma diagnostics
development status conducted at CEA for experimental purpose. Several diagnostics are now under manufacturing or
development which include a Streaked Soft X-ray Imager (SSXI), an Equation Of State (EOS) diagnostic suite (“EOS
pack”), a Full Aperture BackScattering (FABS) diagnostic, a Near Backscattered Imager (NBI), a high resolution 2D
GXI, a high resolution x-ray spectrometer, a specific set of two polar hard x-ray imagers for LEH characterization and a
set of Neutron Time of Flight (NTOF) detectors. We describe here the diagnostics design and performances in terms of
spatial, temporal and spectral resolutions. Their designs have taken into account the harsh environment (neutron yields,
gamma rays, electromagnetic perturbations, debris and shrapnel) and the safety requirements.
In this paper, we report on the latest experimental results on UV-visible multichannel streak cameras for pulse shape
measurement on CEA Laser Megajoule facility. Two main characteristics of these instruments were studied: linear
dynamic range and signal-to-noise ratio. With a standard PHOTONIS P820PSU bilamellar streak tube working at
-10kV, a linear dynamic range of 240 was measured simultaneously in 7 channels at a 25 ns sweep duration. This value
is adequate for the measurement of a high contrast laser pulse. Nevertheless, the signal-to-noise ratio at the bottom of the
channel dynamic range is not sufficient to reach the requirements on the power measurement accuracy (better than few
percents rms). This would require that the maximum output peak current of the P820 streak tube (0.25 mA @ - 10 kV)
be improved by a factor of 5. Finally, the streak cameras that we deploy will have to be fully calibrated.
The first part of the work descried here deals with the metrology of image reducer systems like fiber optic tapers and relay lenses. These components are very useful to adapt the image on the phosphor screen of a streak camera on a limited size CCD array. We measured the collimated and lambertian transmissions, geometric distortions and the Modulation Transfer Function (MTF) of two SCHOTT tapers and of a specific VANNIER relay lens. The second part of this paper is related to a space-time distortions measurement of a nanosecond streak camera with an appropriate CCD readout system (THOMSON TSN506N). A correction method based on two 2D polynomials calculation was also tested. If some experimental conditions are verified, this method could be very efficient and useful when a streak camera is used as a multichannel chronometer (with a fiber optic adapter).