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In 1998, the combined Interferometer and Ultra Small Angle Neutron Scattering (USANS) instrument S18 at the 58 MW High Flux Reactor at the Institute Laue-Langevin in Grenoble (France) started operation. The instrument has been upgraded to allow more advanced neutron optics experiments for fundamental, nuclear and condensed matter physics. The new supermirror guide along with the two channel cut silicon perfect crystals, configured as an advanced high resolution Bonse-Hart camera, provides optimal intensity conditions. A large range of wavelengths is accessible by variations of the Bragg angle and by using different reflecting planes of a properly cut silicon monochromator block in combination with different channel-cut analyzer crystals. The fine adjustment analyzer system is achieved by an advanced piezo drive, which has an accuracy of 0.036 seconds of arc. The basic features of the USANS camera, which takes advantage of a new tail suppression method, and the results of various test measurements concerning intensities, long term stability and the accessible wavelength range will be presented. A high resolution position sensitive detector can either be used to analyze beam profiles or to perform neutron radiography experiments.

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An experimental study has been conducted to assess the feasibility of implementing laser ignition in cryogenic reaction and control and orbital manouvering thrusters. A experimental thruster with a single-coaxial injector element combustion chamber for testing with liquid oxygen/gaseous hydrogen and liquid oxygen/gaseous methane was designed for this purpose. Mapping tests conducted using a standard table top laser revealed that the minimum incident energies required for 100% reliable laser plasma and laser ablation ignition of liquid oxygen/gaseous hydrogen are 72 mJ and 14.5 mJ respectively. In addition, the miniaturised HIPoLas® laser was mounted directly on the thruster and used as ignition system. This paper reports locations of energy deposition, levels of delivered energy and associated ignition probabilities obtained. The results indicate the feasibility of using a laser system for the direct ignition of reaction and control and orbital manouvering thrusters and highlight further investigations and developments necessary for the implementation of miniaturised laser systems for vacuum igntion of cryogenic propellants.

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