Absolute calibration of a streaked optical pyrometer at nanosecond time scale with a luminescent concentrator.

The Streaked Optical Pyrometer (SOP) is a visible diagnostic widely used to study the warm dense matter regime at high energy laser facilities, gas guns, or ion accelerators. It is usually coupled with a Velocity Interferometer System for Any Reflector (VISAR) diagnostic for simultaneous shock wave velocity, reflectivity, and temperature measurements to study the Equation of State (EOS) of materials. While VISAR is a well-mastered technology that provides velocity measurements with low relative uncertainties (close to percent), SOP diagnostics still suffer from high imprecision.

Light recycling in LED-pumped Ce:YAG luminescent concentrators.

We report the development of a high-brightness, high-power Ce:YAG luminescent concentrator pumped by 2240 blue LEDs in quasi-continuous wave operation (10 µs, 10  Hz). Using light confinement and recycling in the three space dimensions, the parallelepiped (1mm×14×mm×200mm) Ce:YAG emits a power of 145 W from a square output surface (1 × 1mm) corresponding to a brightness of 4.6 kW/cm/sr.

Applications of non-periodic multilayer optics for high-resolution x-ray microscopes below 30 keV.

Multilayer mirrors with enhanced bandwidth were developed with special performances for dense plasma diagnostics and mainly for high spatial resolution x-ray imaging. The multilayer coatings are designed to provide broadband x-ray reflectance at low grazing incidence angles. They are deposited onto toroidal mirror substrates.

Vulnerability of CMOS image sensors in Megajoule Class Laser harsh environment.

CMOS image sensors (CIS) are promising candidates as part of optical imagers for the plasma diagnostics devoted to the study of fusion by inertial confinement. However, the harsh radiative environment of Megajoule Class Lasers threatens the performances of these optical sensors. In this paper, the vulnerability of CIS to the transient and mixed pulsed radiation environment associated with such facilities is investigated during an experiment at the OMEGA facility at the Laboratory for Laser Energetics (LLE), Rochester, NY, USA.

Development of an x-ray imaging system for the Laser Megajoule (LMJ).

This imaging system aims at recording images of the core size and shape of an imploding deuterium-tritium (DT) microballoon on LMJ inertial confinement fusion (ICF) experiments. Image acquisition is difficult due to the harsh surrounding created by the fusion reaction, which affects system specifications. This one is made of a scintillator, an optical relay, and a CCD camera shielded from the surrounding.