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Science Mission Directorate Techport Records for 2019 STI-DAA Release Science Mission Directorate TechPort Records for 2019 STI-DAA Release Total Records: 151 Records Updated: November 2019 TechPort ID* Project Title* Project Description* 10575 Advanced X-ray measurements are critical for the understanding of cycles of Multiplexed TES matter and energy in the Universe, for understanding the nature of dark Arrays matter and dark energy, and for probing gravity in the extreme limit of matter accretion onto a black hole. We propose a program to mature the current x-ray microcalorimeter technology, while developing transformational technology that will enable megapixel arrays. X-ray calorimeters based on superconducting transition-edge sensors achieve the highest ener X-ray measurements are critical for the understanding of cycles of matter and energy in the Universe, for understanding the nature of dark matter and dark energy, and for probing gravity in the extreme limit of matter accretion onto a black hole. We propose a program to mature the current x-ray microcalorimeter technology, while developing transformational technology that will enable megapixel arrays. X-ray calorimeters based on superconducting transition-edge sensors achieve the highest energy resolution of any non-dispersive detector technology. The performance of single x-ray calorimeter pixels has reached that required for many possible future missions such as IXO, RAM, and Generation-X, but further optimization is still useful. In the last years, we have made progress in developing techniques to control and engineer the properties of the superconducting transition. We propose to continue this single-pixel optimization, and to improve both the practical and theoretical understanding of the correlation between alpha, beta, and noise to identify favorable regions of parameter space for different instruments. A greater challenge is the development of mature TES x-ray calorimeter arrays with a very large number of pixels. Advances in the last several years have been significant. We have developed modestly large (256 pixel) x-ray calorimeter arrays with time- division SQUID multiplexing, and demonstrated Walsh code-division SQUID multiplexing, which has the potential to allow scaling to much larger arrays. Here we propose to extend this work, and also to introduce a new code-division SQUID multiplexing circuit with extremely compact, low-power elements. Using this approach, it is possible for the first time to fit all of the detector biasing and multiplexing elements underneath an x-ray absorber, allowing in-focal-plane multiplexing. This approach eliminates the requirement to bring leads from each pixel out of the focal plane, while reducing the power dissipati 10779 Optimization of CZT We propose to develop and optimize 0.5 cm thick Cadmium Zinc Detectors with Sub- Telluride (CZT) detectors with very small pixel pitches, i.e. 350 micron mm Pixel Pitches and 600 micron. The proposed innovative R&D program is highly relevant for the EXIST (Energetic X-ray Imaging Survey Telescope) mission, the leading candidate for NASA's black hole finder probe. The new EXIST reference design from the recent Advanced Mission Concept Study uses CZT detectors with a pixel pitch of 600 micron. The proposed work focuses on the optimization of the design of the pixel patterns (pad and gap widths), steering grids, guard rings, and bias rings. For the different designs, the detection efficiencies, energy resolutions, charge sharing properties, and minimum achievable energy thresholds will be evaluated. Dedicated measurements with collimated X-ray beams will be performed to evaluate the accuracy with which the depth of the interaction can be reconstructed based on different methods. Measurements with polarized X-ray beams will be used to put estimates of the X-ray polarization sensitivity of EXIST on a solid footing. Last but not least, the experimental results will be used to fine-tune a 3-D model of the detector response. The proposed R&D is exciting and new in that very thick detectors with very small pixel pitches will be studied for the first time in detail. Effects like charge carrier diffusion and charge carrier repulsion are relatively more important for such detectors than for thinner detectors and/or detectors with larger pixel pitches. 10832 High-contrast "We are developing rotating-baseline nulling-interferometry techniques Nulling and algorithms on the single-aperture Hale and Keck telescopes at near- Interferometry infrared wavelengths, aimed at the detection of faint emission close to Techniques bright stars. Our experiments are aimed at developing simple and robust nulling interferometer systems, that will be useful in the short term for unique observations of faint exozodiacal emission and exoplanets very close to nearby stars, and in the long term for refining and simplifying potential nulling-interferometer-based space missions. Here we propose significant sensitivity, stability, dispersion-reduction and statistical- analysis upgrades to our nulling interferometer systems so as to take our nulling work from the earlier ""basic physics demonstration"" phase to the ""ultimate limiting performance"" stage. Several planned upgrades to our nulling systems will enable forefront nulling capabilities at very low cost. First, we plan to improve the sensitivity of our Palomar Fiber Nuller by two orders of magnitude by replacing our current very modest detector with a much more sensitive IR camera inherited from the Palomar Testbed Interferometer. Second, we plan to improve our fringe stability through a series of upgrades. We will make use of the P3K extreme adaptive optics capability to come on line at Palomar mid-2011 to enable ~ 70 -100 nm stability between subapertures, and also extremely good fiber-coupling stability, together allowing very deep nulls to be measured. We will also upgrade our own post-adaptive optics fringe tracker and implement a novel fluctuation-tolerant fringe tracker algorithm. Third, we will further develop and test novel data reduction algorithms based on the statistics of the null-depth fluctuations to measure accurate astrophysical nulls to levels much deeper than our stabilization level would otherwise allow. Finally, we will also implement a number of dispersion reduction techniques to improve broadband operation an 10833 Fabrication of High "Three factors characterize an X-ray optics fabrication technology: Resolution angular resolution, effective area per unit mass, and production cost per Lightweight X-ray unit effective area. In general, these three factors are always in conflict Mirrors Using with one another. Every telescope that has flown so far represents an Mono-crystalline astronomically useful compromise of these factors. Of three operating X- Silicon ray telescopes, Chandra has been optimized for angular resolution (0.5 arcsecs); Suzaku for effective area per unit mass; and both were optimized in its own way to minimize production cost. We propose an X- ray mirror fabrication method that, when validated and developed, will enable the making of mirror segments with Chandra's angular resolution but with Suzaku's mass per unit area. This method, utilizing an industrial material and commercial polishing techniques, is fast and inexpensive and will enable both small and large X-ray astronomical missions. The method is based on two recent developments. First, revolutionary optical polishing technologies have been developed since the fabrication of the Chandra mirrors. Second, large blocks of mono-crystalline silicon have become readily and inexpensively available. Taking advantage of the grazing incidence geometry of X-ray optics, the new polishing technologies can create mirror segments of high angular resolution on thick silicon blocks fast and at low cost. Given the extremely low internal stress of the nearly perfectly crystalline silicon, these mirrors can then be lightweighted (or sliced off from the silicon block) and still maintain their angular resolution. Instead of the traditional approach of ""lightweight and then polish,"" this method reverses the two steps to ""polish first and then lightweight."" We propose to empirically validate and develop this method in three years. In the first year (FY12) we experiment with making very thin flat mirrors to demonstrate the principle that underpins this method. In the second year (FY13) we extend the experime 10834 Development of a Deformable mirrors (DM) are key to achieving high contrast for any Low Mass, Low mission to image expolanets. Currently Northrup Grumman Xinetics is Power Deformable the only viable source for high-contrast capable deformable mirrors. This Mirror with proposal will help to develop a deformable mirror with integrated driver Integrated Drive electronics, eliminating traditional bulky external driver electronics and Electronics the associated cabling. The DM will have reduced mass and volume and will consume less power than traditional DMs. "Deformable mirrors (DM) are key to achieving high contrast for any mission to image expolanets. Currently Northrup Grumman Xinetics is the only viable source for high-contrast capable deformable mirrors. This proposal will help to develop a deformable mirror with integrated driver electronics, eliminating traditional bulky external driver electronics and the associated cabling. The DM will have reduced mass and volume and will consume less power than traditional DMs. In addition to the reduced mass and volume, the approach incorporates a number of innovations to improve overall DM performance.
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