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The DARHT II accelerator at LANL is preparing a series of preliminary tests at the reduced voltage of 7.8 MeV. The transport hardware between the end of the accelerator and the final target magnet was shipped to LLNL and installed on ETA II. Using the ETA II beam at 5.2 MeV we completed a set of experiments designed reduce start up time on the DARHT II experiments and run the equipment in a configuration adapted to the reduced energy. Results of the beam transport using a reduced energy beam, including the kicker and kicker pulser system will be presented.

As part of the Dual Axis Radiography Hydrotest Facility, Phase I1 (DARHT 11) Multipulse Bremsstrahlung Target effort, we have been performing an investigation of ( I ) the possible adverse effects of backstreaming ion emission from the Bremsstrahlung converter target and(2) the hydrodynamic behavior of the target after the electron beam interaction. Theory predictions show that the first effect would primarily be manifested in the static focusing system as a rapidly varying x-ray spot. From experiments performed on ETA-11, we have shown that the first effect is not strongly present when the beam initially interacts with the target. Electron beam pulses delivered to the target after formation of a plasma are strongly affected, however. Secondly, we have performed measurements of the time varying target density after disassembly was initiated by the electron beam. The measurements presented show that the target density as a function of time compares favorably with our LASNEX models.

The Segment Alignment Maintenance System (SAMS) was installed on McDonald Observatory's Hobby-Eberly Telescope (HET) in August 2001. The SAMS became fully operational in October 2001. The SAMS uses a system of 480 inductive edge sensors to correct misalignments of the HET's 91 primary mirror segments when the segments are perturbed from their aligned reference positions. A special observer estimates and corrects for the global radius of curvature (GRoC) mode, a mode unobservable by the edge sensors. The SAMS edge sensor system and GRoC estimator are able to maintain HET's primary figure for longer durations than previously had been observed. This paper gives a functional description of the SAMS control system and presents performance verification data.

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