Superconducting gravimeter

The superconducting gravimeter was developed and applied to field measurements. The stability of the instrument yielded the highest precision measurements of the Earth tides ever attained. It revealed unprecedented details about the effect of the atmosphere on gravity. Secular variations in gravity and the stability of the instruments were measured by comparing records from co-located instruments. These efforts have resulted in substantial reductions in the noise level at very low frequencies so that the peak differences between two instruments at the same location can be reduced to 0.1 micron gal

High precision tide spectroscopy

Diurnal and long period earth tides were measured to high accuracy and precision with the superconducting gravimeter. The results provide new evidence on the geophysical questions which have been attacked through earth tide measurements in the past. In addition, they raise new questions of potential interest. Slow fluctuations in gravity of order 10 micron gal over periods of 3 to 5 months were observed and are discussed

Rendezvous Launch Operations Planning

This paper deals with the inception and evolution of the simultaneous launch countdown technique. Furthermore, it explains the implementation of the countdown and recycle plans and how the Martin Company\u27s testing and scheduling of the Gemini Launch Vehicle (GLV) is affected by a rendezvous mission

Electron Dynamics in Quantum Dots on Helium Surface

We study single-electron quantum dots on helium surface created by electrodes submerged into the helium. The intradot potential is electrostatically controlled. We find the electron energy spectrum and identify relaxation mechanisms. Strong in-plane confinement significantly slows down electron relaxation. Energy relaxation is due primarily to coupling to phonons in helium. Dephasing is determined by thermally excited ripplons and by noise from underlying electrodes. The decay rate can be further suppressed by a magnetic field normal to the helium surface. Slow relaxation in combination with control over the energy spectrum make localized electrons appealing as potential qubits of a quantum computer.Comment: Presented at Electronic Properties of Two-Dimensional Systems-1

Escape of trapped electrons from a helium surface: a dynamical theory

We present a dynamical theory which incorporates the electron-electron correlations and the effects of external magnetic fields for an electron escaping from a helium surface. Analytical expressions for the escape rate can be obtained in various limits. In particular, the tunneling rate with a parallel magnetic field is presented explicitly.Comment: latex, 3 page