The Berkeley tunable far infrared laser spectrometers

A detailed description is presented for a tunable far infrared laser spectrometer based on frequency mixing of an optically pumped molecular gas laser with tunable microwave radiation in a Schottky point contact diode. The system has been operated on over 30 laser lines in the range 10–100 cm^–1 and exhibits a maximum absorption sensitivity near one part in 10^6. Each laser line can be tuned by ±110 GHz with first-order sidebands. Applications of this instrument are detailed in the preceding paper

Laser Communication Satellite Experiment /LCSE/

Equipment descriptions and procedures for Laser Communication Satellite Experiment /LCSE

ProtoEXIST: Advanced Prototype CZT Coded Aperture Telescopes for EXIST

{\it ProtoEXIST1} is a pathfinder for the {\it EXIST-HET}, a coded aperture hard X-ray telescope with a 4.5 m$^2$ CZT detector plane a 90$\times$70 degree field of view to be flown as the primary instrument on the {\it EXIST} mission and is intended to monitor the full sky every 3 h in an effort to locate GRBs and other high energy transients. {\it ProtoEXIST1} consists of a 256 cm$^2$ tiled CZT detector plane containing 4096 pixels composed of an 8$\times$8 array of individual 1.95 cm $\times$ 1.95 cm $\times$ 0.5 cm CZT detector modules each with a 8 $\times$ 8 pixilated anode configured as a coded aperture telescope with a fully coded $10^\circ\times10^\circ$ field of view employing passive side shielding and an active CsI anti-coincidence rear shield, recently completed its maiden flight out of Ft. Sumner, NM on the 9th of October 2009. During the duration of its 6 hour flight on-board calibration of the detector plane was carried out utilizing a single tagged 198.8 nCi Am-241 source along with the simultaneous measurement of the background spectrum and an observation of Cygnus X-1. Here we recount the events of the flight and report on the detector performance in a near space environment. We also briefly discuss {\it ProtoEXIST2}: the next stage of detector development which employs the {\it NuSTAR} ASIC enabling finer (32$\times$32) anode pixilation. When completed {\it ProtoEXIST2} will consist of a 256 cm$^2$ tiled array and be flown simultaneously with the ProtoEXIST1 telescope

Design of a 5 Degree of Freedom Kinematic Stage for the Dual Crystal Backlighter Imager Diagnostic

The National Ignition Facility (NIF) is home to the world’s most energetic laser. The facility is one of the leading centers in inertial confinement fusion (ICF) experiments to research and understand sustainable fusion energy. To fully document and understand the physics occurring during experiments, precise diagnostics are used for a wide range of purposes. One diagnostic, the crystal backlighter imager (CBI), allows for X-ray imaging of the target at late stages of its implosion. The aim of this project was to increase the current capabilities of the CBI diagnostic with the addition of a second crystal. This thesis focuses on the design development of the 5 degrees of freedom precision stages used to align each of the crystals. The motivations for the addition of a second crystal are covered in the introduction. A ray tracing model was generated to explore the required range of travel for both crystals, as well as explore potential effects of transitioning to a two-crystal system. The requirements of the precision stage are outlined based on the flaws of the current stage and areas with desired improvements. A dynamic analysis was performed on modified supporting hardware for CBI, to determine areas of interest in redesigning components for the two-crystal system. Further research is performed on commercial and literature methods used to design precision optomechanical stages. Finally, the design development is documented outlining the considered options, modifications to the existing system, and the proposed design solution. A design is proposed that meets the project requirements set at the beginning of design development

Beyond the beam : evaluation and application of handheld X-ray fluorescence in archaeology

The starting point of this project was to bridge the gap between the Departments of Analytical Chemistry and Archaeology. Archaeology has evolved from a more historically and art-historically orientated field of research to a fully emancipated science, comfortably adopting GIS, 3D modelling and chemical analysis to serve its own needs. The rapidly evolving field of XRF (X-ray fluorescence) analysis and the development of a new generation of lightweight, high-performance handheld XRF analysers promised new possibilities for in situ elemental determination. The primary aim of this research project was to evaluate the applicability of such a handheld XRF analyser when used in archaeological contexts and to develop a comprehensible protocol for data-processing. To fulfil these objectives, the Olympus Innov-X handheld XRF analyser was obtained and characterised and a work methodology was developed applying established lab protocols used in analytical chemistry. This instrument was then employed in three archaeological case studies where it investigated respectively the provenance of post-medieval Flemish stove-tiles, the origin and distribution of Iron Age red-painted pottery from Mount Kemmel and related sites, and the geochemical composition of archaeological soil features in the Yustyd valley (Russia) during excavations in 2011. The research combined different XRF techniques, with a central role for handheld XRF spectrometry in all selected archaeological applications. In addition, the measurements of both µ-XRF (micro-XRF) and TXRF (Total Reflection XRF) were used to act as a point of reference for the handheld measurements, since reference materials for the archaeological materials under focus are not available, and Raman spectroscopy was used to characterize the pigment in the red-painted pottery. Methodology and characterization of handheld XRF analysers The first part of this thesis consists of three chapters which deal with X-ray fluorescence in general and the instrumentation and methodology that were used in this work. These chapters serve as an introduction to and point of reference for the rest of the thesis. Chapter 1 (Introduction) introduces the research and provides a broader context by placing it in the general evolution of XRF analysis in archaeology and by discussing current issues concerning the validity of handheld XRF. The chosen research strategy and the aims and objectives of this research are also discussed. Chapter 2 (Methodology) provides an overview of the instrumentation that was used in this research and the sample preparation and data processing techniques that were applied per instrument and project. The methodology is applicable to the three archaeological test cases. Chapter 3 (Evaluation of commercial handheld XRF: selecting the right tool for archaeological research) describes the evaluation of six commercially available handheld XRF analysers. The instruments are tested on their performance, stability and ease of use, using a set of standard reference materials and archaeological applications. The characterization of the Olympus Innov-X Delta handheld XRF analyser is another focus of this chapter. The characterization is essential for understanding the potential of the instruments, interpreting the results and configuring an ideal set-up. In the field. The application of hXRF in archaeological research projects In part 2 of the thesis, the hXRF analyser is taken into the field, where it is confronted with three archaeological test cases (Chapters 4-6). The first application is the archaeological and archaeometrical investigation of two ‘virtual dwellings’ in the Yustyd valley (Altai Republic, Russian Federation). In the summer of 2011, two Bronze Age geometric stone settings of the type ‘virtual dwelling’ were excavated by Belgian and Russian archaeologists in the Yustyd valley in the Altai mountains. During this campaign, handheld XRF analysis was used to perform a geochemical survey of the excavated structures in order to see if the soil features, as encountered during excavation, had a different chemical composition than the surrounding soil and if their composition could be attributed to a specific use of the monuments. Soil samples were taken to be further investigated by means of TXRF spectroscopy, a technique with very low detection limits often used for the ultra-trace analysis of particles. Even though we strongly believe in the potential of hXRF for geoarchaeological survey, the results for this study were rather limited. Possibly the harsh environmental conditions and barren soil influenced the results and their interpretation. Another factor might be the archaeological site itself: it is possible that the impact of the activities on the site, some four millennia ago, was too limited to leave traces today. The archaeological levels on the site not only appear to be featureless, but might have been so in origin. Any ritual, funerary or day-to-day use of the sites might have been minimal and not detectable by the chosen XRF technique. Chapter 5 presents the second and most extensive case study: an archaeometrical investigation of Flemish late and post-medieval stove-tiles by means of hXRF and µ-XRF. Stove-tiles are no uncommon goods in Flemish excavations, their origin, however, is unknown since no pottery workshops with evidence of stove-tile production have been found in excavation. The combination of these techniques was used to determine the chemical composition of these tiles and by comparison with locally produced pottery and raw clay, to determine their provenance. Furthermore, the impact of tile-stoves and their imagery as a symbol of status and a representation of identity was discussed and interpreted in relation to the archaeometrical results. The hXRF analyses of the whiteware stove-tiles delivered consistent results showing well-defined groups within the research material, corroborating with the results of the µ-XRF analysis. The study clearly set the whiteware stove-tiles apart from the Antwerp maiolica: either the tiles are imported as a finished product, or the clay was imported and locally used for stove-tile production. The results of the redware stove-tiles on the other hand were more complex. The hXRF results diverged considerably from those of the µ-XRF analysis, giving a completely different view on the relation between the comparative material and the stove-tiles themselves. For now, this divergence is explained by the difference between the two XRF techniques and the detailed measurements that can be taken with the µ-XRF instrument as opposed to the larger beam size of the hXRF instrument and the interference of exterior contamination that is inevitable with handheld XRF. The third and last case study (Chapter 6) covers a provenance-study of Iron Age red-painted pottery. The goal was to investigates whether the red-painted pottery, found on several Iron Age sites in Belgium and Northern France and referred to as Kemmelware, was actually produced in the Mount Kemmel hill fort. hXRF was employed to determine the elemental composition of the pottery while Raman spectroscopy was used to investigate the pigment used for the red slip decorations. The investigation proved very interesting, as the hXRF data clearly demonstrated connections between the Iron Age settlement of Mount Kemmel and those of Kooigembos, Houplin-Ancoisne and Elversele, which can support the hypothesis that the pottery was produced in Kemmel and then distributed to other Iron Age sites. The Houplin-Ancoisne dataset gave evidence of two types of red-painted pottery: one group clearly diverged from the Kemmelware and can be labelled as locally produced red-painted pottery. The pottery from Hove was also chemically and technologically different, again indicating local production. Since only a limited number of sites were investigated, it would be interesting to extend the research with material from other Iron Age settlements, especially from sites in northern France. That way, it might be possible to further delineate the area where the influence of Mount Kemmel is perceptible. Conclusions, future perspectives and final thoughts By now it is clear that there is no such thing as easy answers where chemical analysis of archaeological samples is concerned. It is, however, through extensive application that we can further develop a methodology that allows us to limit the unknown factors that are always present when working with very heterogeneous materials as ceramics and soils. Only by using a lab protocol – also when working in the field –, by attentive monitoring of the data acquisition and by following predetermined steps of data processing, qualitative data can be obtained. In order for hXRF to become fully integrated in archaeology, it must be stressed that archaeologists need to understand the science behind XRF spectrometry and data processing in order to correctly evaluate the produced results and to translate them into an archaeological interpretation. Moreover, knowledge of the chemical process and the composition and variability of archaeological materials will prove indispensable in formulating the most successful research strategies. We hope that this contribution has been a step forwards for a true integration of hXRF into archaeology. In contrast to applying hXRF as a fancy technique because of its publication possibilities, this true integration implies the correct application of hXRF using the protocols and knowhow developed by analytical chemistry and implementing it in an archaeological manner. True integration also means that hXRF analysis in archaeology must not be seen as the sole purpose of a research, but rather as the means to answering well determined archaeological research questions

DEVELOPMENT OF A VERSATILE HIGH SPEED NANOMETER LEVEL SCANNING MULTI-PROBE MICROSCOPE

The motivation for development of a multi-probe scanning microscope, presented in this dissertation, is to provide a versatile measurement tool mainly targeted for biological studies, especially on the mechanical and structural properties of an intracellular system. This instrument provides a real-time, three-dimensional (3D) scanning capability. It is capable of operating on feedback from multiple probes, and has an interface for confocal photo-detection of fluorescence-based and single molecule imaging sensitivity. The instrument platform is called a Scanning Multi-Probe Microscope (SMPM) and enables 45 microm by 45 microm by 10 microm navigation of specimen with simultaneous optical and mechanical probing with each probe location being adjustable for collocation or for probing with known probe separations. The 3D positioning stage where the specimen locates was designed to have nanometer resolution and repeatability at 10 Hz scan speed with either open loop or closed loop operating modes. The fine motion of the stage is comprises three orthogonal flexures driven by piezoelectric actuators via a lever linkage. The flexures design is able to scan in larger range especially in z axis and serial connection of the stages helps to minimize the coupling between x, y and z axes. Closed-loop control was realized by the capacitance gauges attached to a rectangular block mounted to the underside of the fine stage upon which the specimen is mounted. The stage's performance was studied theoretically and verified by experimental test. In a step response test and using a simple proportional and integral (PI) controller, standard deviations of 1.9 nm 1.8 nm and 0.41 nm in the x, y and z axes were observed after settling times of 5 ms and 20 ms for the x and y axes. Scanning and imaging of biological specimen and artifact grating are presented to demonstrate the system operation. For faster, short range scanning, novel ultra-fast fiber scanning system was integrated into the xyz fine stage to achieve a super precision dual scanning system. The initial design enables nanometer positioning resolution and runs at 100 Hz scan speed. Both scanning systems are capable of characterization using dimensional metrology tools. Additionally, because the high-bandwidth, ultra-fast scanning system operates through a novel optical attenuating lever, it is physically separate from the longer range scanner and thereby does not introduce additional positioning noise. The dual scanner provides a fine scanning mechanism at relatively low speed and large imaging area using the xyz stage, and focus on a smaller area of interested in a high speed by the ultra-fast scanner easily. Such functionality is beneficial for researchers to study intracellular dynamic motion which requires high speed imaging. Finally, two high end displacement sensor systems, a knife edge sensor and fiber interferometer, were demonstrated as sensing solutions for potential feedback tools to boost the precision and resolution performance of the SMPM

WRF-Model Data Assimilation Studies of Landfalling Atmospheric Rivers and Orographic Precipitation Over Northern California

In this study, data assimilation methods of 3-D variational analysis (3DVAR), observation nudging, and analysis (grid) nudging were evaluated in the Weather Research and Forecasting (WRF) model for a high-impact, multi-episode landfalling atmospheric river (AR) event for Northern California from 28 November to 3 December, 2012. Eight experiments were designed to explore various combinations of the data assimilation methods and different initial conditions. The short-to-medium range quantitative precipitation forecast (QPF) performances were tested for each experiment. Surface observations from the National Oceanic and Atmospheric Administration\u27s (NOAA) Hydrometeorology Network (HMT), National Weather Service (NWS) radiosondes, and GPS Radio Occultation (RO) vertical profiles from the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) satellites were used for assimilation. Model results 2.5 days into the forecast showed slower timing of the 2nd AR episode by a few hours and an underestimation in AR strength. For the entire event forecasts, the non-grid-nudging experiments showed the lowest mean absolute error (MAE) for rainfall accumulations, especially those with 3DVAR. Higher-resolution initial conditions showed more realistic coastal QPFs. Also, a 3-h nudging time interval and time window for observation nudging and 3DVAR, respectively, may be too large for this type of event, and it did not show skill until 60-66 h into the forecast

Design of the Annular Suspension and Pointing System (ASPS) (including design addendum)

The Annular Suspension and Pointing System is an experiment pointing mount designed for extremely precise 3 axis orientation of shuttle experiments. It utilizes actively controlled magnetic bearing to provide noncontacting vernier pointing and translational isolation of the experiment. The design of the system is presented and analyzed

Application of Synthetic Aperture Radar Interferometry (InSAR) in defining groundwater-withdrawal-related subsidence, Diamond Valley, Nevada

Interferometric Synthetic Aperture Rader (InSAR) technique has been recently used in detecting and monitoring ground displacements such as volcanic activities, earthquakes, landslides and surface deformations caused by fluid extraction. Ground subsidence related to groundwater withdrawal has occurred in many places such as urban areas and large scale agricultural areas. This study utilizes interferometry to detect ground subsidence in an agricultural field, where a large volume of groundwater has been pumped for decades, in Diamond Valley, Nevada. InSAR has proven to have great potential to detect and quantify ground subsidence caused by aquifer system compaction. It mapped ground deformation signals with high spatial detail and resolution of displacement, developed in a groundwater basin in the area, using radar data collected from the ERS-1/ERS-2 and Envisat satellites. The subsidence signal at the south part of the valley, where irrigation wells exist, shows a minimum of 37.6 cm of cumulative subsidence between July 17, 1992 and November 27, 1999 and a 17.5 cm of cumulative subsidence between October 16, 2004 and December 15, 2007.The profile views of the subsidence signals assist in visualizing the deformation geometry which indicates that the subsurface lithology can increase or decrease the deformation. The subsurface model estimated from the history of water table decline and the subsurface lithology distribution approximately correlate with the subsidence signals. Poor correlation occurred where limited availability of good subsurface data and limited spatial coverage of well logs existed

Large space telescope, phase A. Volume 3: Optical telescope assembly

The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design