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Sandia Data Archive (SDA) file specifications

Laros, James H.; Ao, Tommy A.

The Sandia Data Archive (SDA) format is a specific implementation of the HDF5 (Hierarchal Data Format version 5) standard. The format was developed for storing data in a universally accessible manner. SDA files may contain one or more data records, each associated with a distinct text label. Primitive records provide basic data storage, while compound records support more elaborate grouping. External records allow text/binary files to be carried inside an archive and later recovered. This report documents version 1.0 of the SDA standard. The information provided here is sufficient for reading from and writing to an archive. Although the format was original designed for use in MATLAB, broader use is encouraged.

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TYPE SAND Report YEAR 2015
DOIOSTI

Progress and Improvements on Temperature Measurements for Dynamic and Advanced Certification Materials Experiments on Z

Ao, Tommy A.; Harding, Eric H.; Bailey, James E.; Bliss, David E.; Laros, James H.; Knudson, Marcus D.; Laros, James H.

Temperature measurements are very important in shock and ramp type dynamic materials experiments. In particular, accurate temperature measurements can provide stringent additional constraints on determining the equation of state for materials at high pressure. The key to providing these constraints is to develop diagnostic techniques that can determine the temperature with sufficient accuracy. To enable such measurements, we are working to improve our diagnostic capability with three separate techniques, each of which has specific applicability in a particular temperature range. To improve our capability at low temperatures (< 1 eV) we are working on a technique that takes advantage of the change in reflectivity of Au as the temperature is increased. This is most applicable to ramp type experiments. In the intermediate range (~1 eV < T< 5-10 eV) we are improving our optical pyrometry diagnostic by adding the capability of doing an absolute calibration as part of the diagnostic procedure for the shock or shock ramp dynamic materials experiment. This will enable more accurate temperature measurements for shock and shock ramp type experiments. For higher temperatures that occur in very high-pressure shock experiments, above 10 eV, we are developing the capability of doing x-ray Thomson scattering measurements. Such measurements will enable us to characterize strongly shocked or warm dense matter materials. Work on these diagnostic approaches is summarized in this report.

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TYPE SAND Report YEAR 2014
DOIOSTI

Dynamic temperature measurements with embedded optical sensors

Dolan, Daniel H.; Seagle, Christopher T.; Ao, Tommy A.

This report summarizes LDRD project number 151365, \Dynamic Temperature Measurements with Embedded Optical Sensors". The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.

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TYPE SAND Report YEAR 2013
DOIOSTI
Results 76–100 of 145
Results 76–100 of 145