LLE Review 144

Review 144


This volume of the LLE Review, covering July–September 2015, features "The Hydrogen Isotope Separation System." This article reports on LLE's newly commissioned hydrogen Isotope Separation System (ISS). The ISS uses two columns—palladium on kieselguhr and cold molecular sieve—that act in a complementary manner to separate the hydrogen species by mass. The ISS yields tritium purities exceeding 99.9%. Outfitting LLE with ISS expands the Laboratory's capabilities to explore fusion-reaction physics over a very broad range of deuterium–tritium ratios in a controlled manner.

Additional highlights of research presented in this issue include the following:

  • Single-shot high-resolution characterization of optical pulses by spectral phase diversity is studied. Pulse-shape reconstruction for pulses shorter than the photodetection impulse response has been demonstrated. An assembly composed of splitters and dispersive delay fibers has been used to generate 64 ancillary pulses whose instantaneous power can be detected in a single shot with a photodiode and real-time oscilloscope.
  • Finishing of single crystal and chemical-vapor–deposited polycrystalline zinc sulfide (ZnS) via chemically and mechanically modified magnetorheological (MR) fluids is reported. When polishing ZnS samples with pH 5 and pH 6 MR fluids, anisotropy in material removal rate (mrr) were found. However, when polishing ZnS samples with the modified MR fluid at pH 4, minimal variation in mrr among the four single-crystal planes was observed, and reduction in surface artifacts was achieved on the polycrystalline material.
  • Interferometric strain measurements with a fiber optic probe are described. A single-mode optical fiber strain probe and a novel fiber-contained heterodyne interferometer have been developed as a position feedback sensor for an active vibration stabilization system for cryogenic inertial confinement fusion targets. Experimental measurements of the sensor showing good agreement with reference resistive-strain- gauge measurements are presented.
  • R. D. Petrasso reports on the Seventh Omega Laser Facility Users Group Workshop.
  • This volume concludes with a summary of LLE's Summer High School Research Program, the FY15 Laser Facility Report, and the National Laser Users' Facility and External Users' Programs.

Table of Contents