LLNL researchers have developed a high average power Faraday rotator that is gas-cooled and uniquely designed to dissipate heat uniformly so that it does not build up in the optical component and affect its performance.  The Faraday rotator material is sliced into smaller disks like a loaf of bread so that high speed helium gas can flow between the slices.  With this highly efficient cooling…

This novel detector for characterizing IFE implosions is an alternative to the current RTNADs to measure neutron fluxes > 3x10¹¹ neutrons/cm² at high shot rates. The detector consists of a stack of small square metal wafers separated by thin insulating spacers. Every other wafer is held at high voltage while the remaining wafers are grounded. The stack acts as an…

This invention discloses a method to minimize transient variations in the wavelength- and/or pointing-behavior of an optic, without requiring a reduction in its thermal resistance, optical absorption, or operating irradiance. The invention employs a combination of a time-varying heat source and time-varying thermal resistance and/or heat sink temperature to achieve temperature stability of the…

This invention concerns a new type of optic: a transient gas or plasma volume grating produced indirectly by small secondary lasers or directly by nonlinear processes using the primary beams themselves. When used in conjunction with advantageously placed shielding it offers a means of protecting the final optical components of a high-repetition-rate IFE facility. These transmission optics are…

LLNL researchers have designed and tested performance characteristics for a multichannel pyrometer that works in the NIR from 1200 to 2000 nm. A single datapoint without averaging can be acquired in 14 microseconds (sampling rate of 70,000/s). In conjunction with a diamond anvil cell, the system still works down to about 830K.