WAND2-A versatile wide angle neutron powder/single crystal diffractometer.

Wide Angle Neutron Diffractometer Squared is a high-flux versatile diffractometer with a 2-Dimensional Position Sensitive Detector at the High Flux Isotope Reactor. The instrument has strengths in both powder and single crystal diffraction. It is a unique instrument in the neutron scattering landscape of North America, and its capabilities are at least equal to similar instruments in the world.

A novel technique for real-time estimation of edge pedestal density gradients via reflectometer time delay data.

A new model-based technique for fast estimation of the pedestal electron density gradient has been developed. The technique uses ordinary mode polarization profile reflectometer time delay data and does not require direct profile inversion. Because of its simple data processing, the technique can be readily implemented via a Field-Programmable Gate Array, so as to provide a real-time density gradient estimate, suitable for use in plasma control systems such as envisioned for ITER, and possibly for DIII-D and Experimental Advanced Superconducting Tokamak. The method is based on a simple edge plasma model with a linear pedestal density gradient and low scrape-off-layer density. By measuring reflectometer time delays for three adjacent frequencies, the pedestal density gradient can be estimated analytically via the new approach. Using existing DIII-D profile reflectometer data, the estimated density gradients obtained from the new technique are found to be in good agreement with the actual density gradients for a number of dynamic DIII-D plasma conditions.

Development of an implantable oximetry-based organ perfusion sensor.

A sensor system enabling real-time monitoring of organ perfusion following transplantation is presented. This system uses a three wavelength oximetry-based approach. The instrument is intended for implantation at the organ site during transplantation to provide real-time reporting of the perfusion status of the tissue for 7-10 days following the procedure. Data is transmitted from the sensor to a localized receiver using direct sequence spread spectrum techniques at 916 MHz. In this paper, the sensing method and associated electronics implementation are presented. The present status of system miniaturization is summarized along with plans for future miniaturization efforts. Preliminary sensor data is presented demonstrating the efficacy of the technique.