Electrostatic Vacuum Research Articles

The Gravity Probe B electrostatic gyroscope suspension system (GSS)

A spaceflight electrostatic suspension system was developed for the Gravity Probe B (GP-B) Relativity Mission’s cryogenic electrostatic vacuum gyroscopes which serve as an indicator of the local inertial frame about Earth. The Gyroscope Suspension System (GSS) regulates the translational position of the gyroscope rotors within their housings, while (1) minimizing classical electrostatic torques on the gyroscope to preserve the instrument’s sensitivity to effects of General Relativity, (2) handling the effects of external forces on the space vehicle, (3) providing a means of precisely aligning the spin axis of the gyroscopes after spin-up, and (4) acting as an accelerometer as part of the spacecraft’s drag-free control system. The flight design was tested using an innovative, precision gyroscope simulator Testbed that could faithfully mimic the behavior of a physical gyroscope under all operational conditions, from ground test to science data collection. Four GSS systems were built, tested, and operated successfully aboard the GP-B spacecraft from launch in 2004 to the end of the mission in 2008.

The development of enabling technologies for producing active interrogation beams

A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

Electrostatic fields with straight flux lines

Electrostatic vacuum fields having straight flux lines—so that flux lines are possible orbits for charged test particles—are shown to be restricted to those cases which come to mind immediately: the fields of a point charge, an infinite straight charged wire, and the homogeneous fields. The length of the argument is surprising.

Coordinate modelling for static axially symmetric electrovac metrics

A new technique of coordinate modelling is introduced. It is shown that the static axially symmetric electrovac field equations are easier to solve in terms of coordinates which are specially adapted to the electrostatic equipotential contours of the system. Several new exact solutions are readily found by separating variables and by employing complex analytic functions. A framework for the construction of general solutions of the axially symmetric electrostatic vacuum field equations is presented and the Weyl solutions are shown to be trivially extractable.

An investigation of axially symmetric electrovac solutions

For the axially symmetric, electrostatic vacuum problem, there are three unknowns:g00,g11, and φ, the electrostatic field. Herlt, using his generation methods, has presented several new solutions by explicitly givingg00 andφ only. Theg11 is now determined in two cases and a detailed discussion of these solutions is given. The solutions do not, in general, possess the overlapping equipotential structure [g00=g00(φ)] which characterizes the Weyl class. One of the classes contains metrics which can be physically interpreted as representing exterior space-times of non-Weyl “two-body”-type charged “point” sources. With the specialization of the arbitrary parameters, the above solutions do reduce to known Weyl solutions. The Bonnor solution is a member of one of the above classes and consequently a possible physical reinterpretation of this solution is given. Kinnersley transformations applied to the above classes yield stationary space-times with line singularities and NUT-like asymptotic behavior.

Generation of intense pulsed ion beams

An electrostatic vacuum triode is described in which it is possible to efficiently produce intense ion beams in the energy range around 100 keV for short times (∼50 nsec). In experiments to date, results have shown excellent agreement with predicted behavior. Equivalent proton currents of almost 500 A have been obtained at a peak energy in excess of 100 keV. The triode can easily be adapted to existing electron beam facilities.