Microwave surface resistance of reactively sputtered NbN thin films

The surface resistance of niobium nitride (NBN) thin films was measured at 7.78 and 10.14 GHz in the temperature range of 1.5 to 4.2 K. The films were reactively sputtered on sapphire substrates to a thickness of approximately 1 micron. The surface resistance was determined by measuring the quality factor (Q) of the TE sub 011 mode of a lead-plated copper cavity where the NbN served as one end-cap of the cavity

Global Earth Response to Loading by Ocean Tide Models

Mathematical and programming techniques to numerically calculate Earth response to global semidiurnal and diurnal ocean tide models were developed. Global vertical crustal deformations were evaluated for M sub 2, S sub 2, N sub 2, K sub 2, K sub 1, O sub 1, and P sub 1 ocean tide loading, while horizontal deformations were evaluated for the M sub 2 tidal load. Tidal gravity calculations were performed for M sub 2 tidal loads, and strain tensor elements were evaluated for M sub 2 loads. The M sub 2 solution used for the ocean tide included the effects of self-gravitation and crustal loading

Operational parameters for the superconducting cavity maser

Tests of the superconducting cavity maser (SCM) ultra-stable frequency source have been made for the first time using a hydrogen maser for a frequency reference. In addition to characterizing the frequency stability, the sensitivity of the output frequency to several crucial parameters was determined for various operating conditions. Based on this determination, the refrigeration and thermal control systems of the SCM were modified. Subsequent tests showed substantially improved performance, especially at the longest averaging times

Use of inedible wheat residues from the KSC-CELSS breadboard facility for production of fungal cellulase

Cellulose and xylan (a hemicellulose) comprise 50 percent of inedible wheat residue (which is 60 percent of total wheat biomass) produced in the Kennedy Space Center Closed Ecological Life Support System (CELSS) Breadboard Biomass Production Chamber (BPC). These polysaccharides can be converted by enzymatic hydrolysis into useful monosaccharides, thus maximizing the use of BPC volume and energy, and minimizing waste material to be treated. The evaluation of CELSS-derived wheat residues for production for cellulase enzyme complex by Trichoderma reesei and supplemental beta-glucosidase by Aspergillus phoenicis is in progress. Results to date are given

Performance of a superconducting cavity stabilized ruby maser oscillator

We first described an all-cryogenic oscillator system at the 1982 Applied Superconductivity Conference in Knoxville. This oscillator consists of a ruby cavity maser stabilized by a high-Q superconductor-on-sapphire resonator. The maser provides gain with very low noise and small power dissipation, while the sapphire substrate's thermal coefficient of expansion is 100 times smaller than that of superconducting metals. Having tested the major components and proved them satisfactory to the design, we have now assembled the first such oscillator and tested its performance in several preliminary configurations. The results of stability tests in a more advanced configuration will be reported. We shall describe this oscillator and shall report on its performance as a high-stability frequency source

Spin-Excitation Mechanisms in Skyrme-Force Time-Dependent Hartree-Fock

We investigate the role of odd-odd (with respect to time inversion) couplings in the Skyrme force on collisions of light nuclei, employing a fully three-dimensional numerical treatment without any symmetry restrictions and with modern Skyrme functionals. We demonstrate the necessity of these couplings to suppress spurious spin excitations owing to the spin-orbit force in free translational motion of a nucleus but show that in a collision situation there is a strong spin excitation even in spin-saturated systems which persists in the departing fragments. The energy loss is considerably increased by the odd-odd terms

Superconductor-sapphire cavity for an all-cryogenic SCSO

To develop a superconducting cavity stabilized oscillator (SCSO) as a frequency standard, we are studying the properties of cavities consisting of a single crystal of sapphire surrounded by a superconducting film. Measurements of quality factors of spherical and cylindrical samples of sapphire are reported. Loss values less than 2 × 10^-9 have been measured at a temperature of 1.45K. A design for an all-cryogenic SCSO is described, with particular emphasis on the cavity requirements. We conclude that such a design would allow greatly enhanced stability of operation due substantially to the thermal and physical properties of the sapphire substrate. Cavity Q requirements are relatively modest, with better than 10^-16 frequency stability predicted for a Q of 10^8