The drilling of copper using a dual-pulse femtosecond laser with wavelength of 800 nm, pulse duration of 120 fs and a variable pulse separation time (0.1–150 ps) is investigated theoretically. A one-dimensional two-temperature model with temperature-dependent material properties is considered, including dynamic optical properties and the thermal-physical properties. Rapid phase change and phase...

A globally-averaged, pulsed inductive plasma model is reproduced and utilized to investigate pre-ionization conditions for a pulsed inductive plasma accelerator. Attention is given to better quantifying the formation and energy conversion/loss processes associated with the pre-ionization stage. Simulations are completed for different power input pulse duration, seed plasma density, and total in...

We analyze the path arrival rate for an inroom radio channel with directive antennas. The impulse response of this channel exhibits a transition from early separate components followed by a diffuse reverberation tail. Under the assumption that the transmitter’s (or receiver’s) position and orientation are picked uniformly at random we derive an exact expression of the mean arrival rate for a re...

This paper applies and reenes the ProCoS approach to trans-formational design of real-time systems to a benchmark case study, the Karlsruhe production cell 10, 9]. We start by formalizing the informal requirements of 10, 9] in Duration Calculus and end with a distributed controller architecture where all components are speciied in the program speciication language SL time 18]. Novel is the full...

We propose a scheme for bright sub-100-femtosecond X-ray radiation generation using smallangle Thomson scattering. Coupling high-brightness electron bunches with high-power ultrafast laser pulses, radiation with photon energies between 8to 40-keV can be generated with pulse duration comparable to that of the incoming laser pulse with peak spectral brightness close to those of the third-generati...

Recent progress is described to implement two approaches to specially tailor trapbased positron beams. Experiments and simulations are presented to understand the limits on the energy spread and pulse duration of positron beams extracted from a Penning-Malmberg (PM) trap after the particles have been buffer-gas cooled (or heated) in the range of temperatures 1000 T 300 K. These simulations are ...

We demonstrate second-order interferometric autocorrelation of a pulse in the vacuum-ultraviolet (VUV) spectral range using an optical arrangement equivalent to a Michelson interferometer. In an all-reflective design, wavefront splitting is realized with two moveable interdigitated reflective gratings forming a diffraction pattern with well separated orders and an intensity distribution dependi...

LED PWM dimming application for large scale LED video displays is analyzed. The need for short light pulse duration is outlined. PWM dimming with short driving pulses is investigated experimentally. The LED response time skew introduces the nonlinearity for PWM dimming. For LED response time skew estimation, a method is suggested that has been successfully applied to measure some of today’s mar...

In this paper, the problem of verifying a timed automaton for a Duration Calculus formula in the form of linear duration invariants 2] is addressed. We show that by linear programming, a particular class of timed automata including the class of real-time automata as a proper subset, can be checked for linear duration invariants. The so-called real-time regular expressions is introduced to expre...

We report on the experimental results of microand nanostructures fabricated on the surface of fused silica by a train of two femtosecond laser pulses, a tightly focused 266 nm (ultraviolet, UV) pulse followed by a loosely focused 800 nm (infrared, IR) pulse. By controlling the fluence of each pulse below the damage threshold, microand nanostructures are fabricated using the combined beams. The ...