Results of a search for deuterium at 25-50 GC/c using a magnetic spectrometer

A method is presented for separately identifying isotopes using a Cerenkov detector and a magnet spectrometer. Simulations of the method are given for separating deuterium from protons. The simulations are compared with data gathered from the 1979 flight of the New Mexico State University balloonborne magnet spectrometer. The simulation and the data show the same general characteristics lending credence to the technique. The data show an apparent deuteron signal which is (11 + or - 3)% of the total sample in the rigidity region 38.5 to 50 GV/c. Until further background analysis and subtraction is performed this should be regarded as an upper limit to the deuteron/(deuteron+proton) ratio

Analytical and experimental study of the effects of wing-body aerodynamic interaction on space shuttle subsonic flutter

The effects on flutter of the aerodynamic interaction between the space shuttle bodies and wing, 1/80th-scale semispan models of the orbiter wing, the complete shuttle and intermediate component combinations were tested in the NASA Langley Research Center 26-inch Transonic Blowdown Wind Tunnel. Using the double lattice method combined with slender body theory to calculate unsteady aerodynamic forces, subsonic flutter speeds were computed for comparison. Using calculated complete vehicle modes, flutter speed trends were computed for the full scale vehicle at an altitude of 15,200 meters and a Mach number of 0.6. Consistent with findings of the model studies, analysis shows the shuttle to have the same flutter speed as an isolated cantilevered wing

Experimental investigation of the mechanical micro structural and thermal properties of thin CrAIN layers deposited by PVD technique for various aluminum percentages

The thin film of chromium nitride and their derivatives obtained by the filing process physical vapor deposition attract more and more attention from industry given their high resistance to wear. This quality of these coatings may be linked to their good mechanical and tribological properties. Several experimental investigations have led to the development of CrAlN (Chronium Aluminum Nitride) hard coatings by varying the aluminum target bias voltage, in preference to the traditional CrN coating. The present work is based on the investigation of physical and mechanical properties of CrAlN coating deposited on a silicon substrate and the effect of the aluminum proportion on their variation. The results demonstrate that variation in aluminum proportion alters the resulting columnar morphology, porosity and the thermal properties. The correlation between aluminum proportions in CrAlN coatings and his thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by decrease of the stitch parameter dimension

Extending the Eikonal Approximation to Low Energy

E-CDCC and DEA, two eikonal-based reaction models are compared to CDCC at low energy (e.g. 20AMeV) to study their behaviour in the regime at which the eikonal approximation is supposed to fail. We confirm that these models lack the Coulomb deflection of the projectile by the target. We show that a hybrid model, built on the CDCC framework at low angular momenta and the eikonal approximation at larger angular momenta gives a perfect agreement with CDCC. An empirical shift in impact parameter can also be used reliably to simulate this missing Coulomb deflection.Comment: Contribution to the proceedings of the Conference on "Advances in Radioactive Isotope Science" (ARIS2014). 6 pages, 4 figure

A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation

A new measurement of the cosmic ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a ten-fold improvement in statistics with respect to all previously published data. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g. dark matter particle annihilations.Comment: 10 pages, 4 figures, 1 tabl

Feedback-enhanced algorithm for aberration correction of holographic atom traps

We show that a phase-only spatial light modulator can be used to generate non-trivial light distributions suitable for trapping ultracold atoms, when the hologram calculation is included within a simple and robust feedback loop that corrects for imperfect device response and optical aberrations. This correction reduces the discrepancy between target and experimental light distribution to the level of a few percent (RMS error). We prove the generality of this algorithm by applying it to a variety of target light distributions of relevance for cold atomic physics.Comment: 5 pages, 4 figure

Large aircraft handling qualities

The short period frequency requirements of MIL-F-8785C are applicable to the very large transport aircraft simulated. The large aircraft simulated meet the requirements of NASA CR-159236 for effective time delay and pitch transient peak ratio. However, the requirements of this reference for the effective rise time parameter are believed to be too convservative for very large transport aircraft. Data obtained to date as well as other data indicate that MIL-SPEC requirements for the parameter t(phi=30 degrees) are too conservative for very large transport aircraft. The results of the present study indicate that t(phi=30 degrees) of less than 6 sec should result in ""acceptable'' roll response characteristics, and t(phi=30 degrees) of less than 4.0 sec should result in ""satisfactory'' roll response