Special treatment reduces helium permeation of glass in vacuum systems

Internal surfaces of the glass component of a vacuum system are exposed to cesium in gaseous form to reduce helium permeation. The cesium gas is derived from decomposition of cesium nitrate through heating. Several minutes of exposure of the internal surfaces of the glass vessel are sufficient to complete the treatment

Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Summary technical report, 1 Feb. 1965 - 1 Mar. 1966

Cryosorption, diffusion pump, and pressure calibration studies in extreme vacuum science and technology application progra

Extreme vacuum technology including cryosorption, diffusion pump and pressure calibration studies Quarterly status report no. 8, 1 May - 1 Aug. 1965

Cryosorption, diffusion pump, and low pressure calibration studies on Penning gauge and cold cathode magnetro

Study of low pressure application of the orbitron

Evaluation of low pressure performance of orbitron ionization gaug

From Feynman Proof of Maxwell Equations to Noncommutative Quantum Mechanics

In 1990, Dyson published a proof due to Feynman of the Maxwell equations assuming only the commutation relations between position and velocity. With this minimal assumption, Feynman never supposed the existence of Hamiltonian or Lagrangian formalism. In the present communication, we review the study of a relativistic particle using ``Feynman brackets.'' We show that Poincar\'e's magnetic angular momentum and Dirac magnetic monopole are the consequences of the structure of the Lorentz Lie algebra defined by the Feynman's brackets. Then, we extend these ideas to the dual momentum space by considering noncommutative quantum mechanics. In this context, we show that the noncommutativity of the coordinates is responsible for a new effect called the spin Hall effect. We also show its relation with the Berry phase notion. As a practical application, we found an unusual spin-orbit contribution of a nonrelativistic particle that could be experimentally tested. Another practical application is the Berry phase effect on the propagation of light in inhomogeneous media.Comment: Presented at the 3rd Feynman Festival (Collage Park, Maryland, U.S.A., August 2006

Extreme vacuum technology developments

Ultrahigh vacuum environments technology development

Pose, posture, formation and contortion in kinematic systems

The concepts of pose, posture, formation and contortion are defined for serial, parallel and hybrid kinematic systems. Workspace and jointspace structure is examined in terms of these concepts. The inter-relationships of pose, posture, formation and contortion are explored for a range of robot workspace and jointspace types

Spin Hall effect of Photons in a Static Gravitational Field

Starting from a Hamiltonian description of the photon within the set of Bargmann-Wigner equations we derive new semiclassical equations of motion for the photon propagating in static gravitational field. These equations which are obtained in the representation diagonalizing the Hamiltonian at the order $\hbar$, present the first order corrections to the geometrical optics. The photon Hamiltonian shows a new kind of helicity-magnetotorsion coupling. However, even for a torsionless space-time, photons do not follow the usual null geodesic as a consequence of an anomalous velocity term. This term is responsible for the gravitational birefringence phenomenon: photons with distinct helicity follow different geodesics in a static gravitational field.Comment: 6 page

Extreme vacuum technology including cryopump, getter-ion pump, diffusion pump and pressure standardization studies Summary technical report, 16 Jun. 1966 - 16 Jun. 1967

Ultrahigh vacuum technology including cryopump, getter ion pump, diffusion pump, and pressure standardization studie

Appearance of Gauge Fields and Forces beyond the adiabatic approximation

We investigate the origin of quantum geometric phases, gauge fields and forces beyond the adiabatic regime. In particular, we extend the notions of geometric magnetic and electric forces discovered in studies of the Born-Oppenheimer approximation to arbitrary quantum systems described by matrix valued quantum Hamiltonians. The results are illustrated by several physical relevant examples