We report on a simple method for an active position stabilization of an atomic cloud trapped in a magneto-optical trap operating on the narrow 182 kHz intercombination line of atomic ytterbium. Our method makes use of the significant sensitivity of the position of a narrow-line magneto-optical trap (MOT) on the laser frequency. After in situ detection of the MOT position using a Pi Camera, an error signal is generated by a Raspberry Pi, which is directly fed back onto the laser frequency. Thus, perturbations of the MOT position, e.g., due to drifts of the Zerodur cavity to which the MOT laser is stabilized or the ambient magnetic field, can be compensated directly. Our method allows for long-term stabilization of the MOT position on a 10 µm scale and thus improves loading of a tightly focused optical trap.The Opacity Platform on the National Ignition Facility (NIF) has been developed to measure iron opacities at varying densities and temperatures relevant to the solar interior and to verify recent experimental results obtained at the Sandia Z-machine, that diverge from theory. The first set of NIF experiments collected iron opacity data at ∼150 eV to 160 eV and an electron density of ∼7 × 1021 cm-3, with a goal to study temperatures up to ∼210 eV, with electron densities of up to ∼3 × 1022 cm-3. Among several techniques used to infer the temperature of the heated Fe sample, the absolutely calibrated DANTE-2 filtered diode array routinely provides measurements of the hohlraum conditions near the sample. However, the DANTE-2 temperatures are consistently low compared to pre-shot LASNEX simulations for a range of laser drive energies. We have re-evaluated the estimated uncertainty in the reported DANTE-2 temperatures and also the error generated by varying channel participation in the data analysis. An uncertainty of ±5% or better can be achieved with appropriate spectral coverage, channel participation, and metrology of the viewing slot.A new x-ray isothermal furnace has been developed, suitable for in situ observations of semi-solid processes including the transition from dendritic to globulitic grain morphology and grain coarsening in metallic samples. A homogeneous, isothermal temperature field is achieved using a novel heater concept. The furnace structure is sandwich-like with heating elements positioned in the beam line and parallel to the sample. Planar heat transfer to the sample enables measurements with low cooling rates and a minimized temperature gradient. Cooling rates from 0.1 to 15 K min-1 can be controlled in the temperature range 1170-670 K. The furnace setup is integrable in the existing rotatable laboratory x-ray facility (X-RISE) at the German Aerospace Center (DLR). In this setup, an effective pixel size of 3 μm and a field of view of 8 mm in diameter can be achieved. Preliminary solidification and semi-solid experiments in the hypo-eutectic alloy systems Al-Ge and Al-Cu, inoculated with Al-5Ti-1B grain refiner, are presented. They indicate a very uniform temperature distribution in the sample.Pressure calibration for most diamond-anvil cell (DAC) experiments is mainly based on the ruby scale, which is key to implementing this powerful tool for high-pressure study. However, the ruby scale can often hardly be used for programmably controlled DAC devices, especially the piezoelectric-driving cells, where a continuous pressure calibration is required. In this work, we present an effective pressure gauge for DACs made of Manganin metal based on the four-probe resistivity measurements. Pressure dependence of its resistivity is well established and shows excellent linear relations in the 0-30 GPa pressure range with a slope of 23.4 (9) GPa for the first-cycle compression, in contrast to that of multiple-cycle compression and decompression having a nearly identical slope of 33.7 (4) GPa likely due to the strain effect. In addition, the such-established Manganin scale can be used for continuously monitoring the cell pressure of piezoelectric-driving DACs, and the reliability of this method is also verified by the fixed-point method with a Bi pressure standard. Realization of continuous pressure calibration for programmably controlled DACs would offer many opportunities for the study of dynamics, kinetics, and critical behaviors of pressure-induced phase transitions.High-temperature, high-density experiments require a simultaneous understanding of temporal and spectral regions. The spectral x-ray streak camera (SXSC) is a new high-temporal-resolution spectral x-ray diagnostic system that allows researchers to differentiate between soft and hard x-ray regions. The diagnostic offers three spectral channels with a wide spectral range, one direct channel that includes a filter and two indirect channels that include both mirrors and filters. The opto-mechanical design positions the filtered radiation at three different locations along the streak photo-cathode (PC) slit to provide time-dependent spectral channels with pico-second temporal resolution. A moderate spatial resolution (150-700 μm) is achieved using slits perpendicular to the PC slit, while the slit width is optimized according to the central channel wavelength (for each channel). The diagnostic system covers a spectral range of 30-500 eV for the mirror channels and >1300 eV for the direct channel. The temporal and spatial axes of the streak camera are calibrated with respect to a sequence of x-ray pulses. The SXSC diagnostic system is tested and analyzed using Marshak-wave emission from an SiO2 foam that was heated by a laser-beam irradiated halfraum. The SXSC results are compared to measurements from an x-ray diode array with similar spectral channels.Digital holography has been proposed to fulfill a need for an imaging diagnostic capable of in situ monitoring of surface erosion caused by plasma-material interaction in nuclear fusion devices. A digital holography diagnostic for 3D surface erosion measurement has been developed at Oak Ridge National Laboratory with the goal of deployment on a plasma device. A proof-of-concept in situ demonstration is planned which would involve measurement of plasma erosion on targets exposed to an electrothermal arc source. This work presents the results of an ex situ characterization of the capability and limitations of holographic imaging of targets exposed to the arc source. N-Formyl-Met-Leu-Phe molecular weight Targets were designed to provide a fiducial for comparison of deformed and unaffected areas. The results indicated that the average net erosion was ∼150 nm/plasma exposure, which is expected to be within the diagnostic’s measurement capacity. Surface roughness averages determined by holographic image analysis showed good agreement with measurements taken with a profilometer.