The unitary evolution operators generated by periodically varying elastic potentials including the Mathieu case are studied. The evolution operations in the stability areas of the Strutt diagram admit effective (Floquet) Hamiltonians generalizing the orthodox oscillators. The points on the separatrices represent two exceptional types of unitary operations, imitating (in a soft way) the results of the sudden δ-like kicks of the elastic potential, or the distorted free evolution (in accelerated, slowed down or even negative time). In all domains the dynamical phenomena illustrate a non-trivial relation between the micro- and macroscopic motion scales.

Abstract. We examine the behaviour of charged particles in homogeneous, constant and/or oscillating magnetic fields in the non-relativistic approximation. A special role of the geometric center of the particle trajectory is elucidated. In quantum case it becomes a 'fuzzy point' with non-commuting coordinates, an element of non-commutative geometry which enters into the traditional control problems. We show that its application extends beyond the usually considered time independent magnetic fields of the quantum Hall effect. Some simple cases of magnetic control by oscillating fields lead to the stability maps differing from the traditional Strutt diagram.

In situ incorporation and activation of boron into silicon carbide is demonstrated using excimer laser recrystallization in a boron trifluoride ambient. Rutherford backscattering spectroscopy and x-ray analysis demonstrate that there is no crystalline damage during recrystallization at laser fluences below ∼1.4 J/cm2. Point-contact current–voltage measurements confirm dopant activation, and the formation of shallow (∼90 nm) pn  junctions in silicon carbide. This technique may be applied to the fabrication of shallow junctions and low resistance contacts in silicon carbide power devices without ion implantation and furnace annealing.

High-power microwave tube systems used on Navy radars and in communication systems are primary cost drivers as can be seen from the $100M spent yearly on replacing malfunctioning highpower microwave tubes in the Fleet. In many cases (estimated at over 25%), perfectly operating tubes are inadvertently replaced because there is insufficient in situ monitoring equipment available to diagnose specific problems within the system. High-power microwave vacuum tubes used in the fleet combat systems are equipped with only a minimum on-line component condition assessment capability with little or no built-in prognostic capability to provide advance warning of a developing failure situation. In the earlier phases of the Microwave Tube Built-In Test (MTBIT) program (1999-2001), a new advanced nondestructive testing technique was demonstrated using acoustic emission (AE) for in-situ monitoring of normal and abnormal performance of high-power radar tubes such as magnetrons, traveling wave tubes (TWTs), and klystrons. This report details the next step in transitioning the laboratory MTBIT system into a system that is compatible with condition-based maintenance systems employing the Integrated Condition Assessment System (ICAS) used by the Fleet. This report identifies the interface requirements for the sensors and ICAS, as well as accommodating limitations of the ICAS software, which currently is not configured to accommodate the sensor data rates and data sets required. Ten new electronic circuits were designed, built, and tested to interface the outputs of the current sensor and acoustic emission sensor attached to a magnetron through an OPTO22 digital and analog input/output (I/O) hardware along with its Optomux protocol and the ICAS software (Version 4.11). The ICAS software, developed by IDAX Inc., is a 32-bit Microsoft Windows NT based data analysis and integration tool currently in use by the Navy for the performance monitoring of mechanical systems on surface ships. The complete computerized system to monitor the in-situ performance of the high-power microwave tube was developed, tested, and reported here. The system could be extended to achieve the same goal with other microwave tubes such as TWTs and klystrons with minor modifications.

Ion implantation ion source equipment employing MO or W arc chambers, W filaments and A1203 insulators allow F from BF3 source gasses to chemically react, forming metallic fluorides and oxides that are volatile species at common operating temperatures. These gases get ionized and extracted together with the desired ions. There is evidence that all MoFx molecules (1Cxc6) and probably some clusters exist in the plasma and get dissociated after extraction. It can be speculated that some oxides MOO, with l