A 128-channel picoammeter system is constructed based on instrumentation amplifiers. Taking advantage of a high electric potential and narrow bandwidth in DC energetic charged beam measurements, a current resolution better than 5 fA can be achieved. Two sets of 128-channel strip electrodes are implemented on printed circuit boards and are employed for ion and electron beam current distribution ...

Numerical and asymptotic results are presented for a coupled PDE system that models recent experiments of the selffocussing of laser light in a nematic liquid crystal. This study complements previous asymptotic analyses which, in a narrow-beam limit, describe two essential features observed in nematic self-focussing the undulation and filamentation of a laser beam. These numerical computations ...

The DESY II Test Beam Facility is a key infrastructure for modern high energy physics detector development, providing particles with small momentum spread in range from 1 to 6 GeV user groups e.g. the LHC experiments and Belle as well generic R&D. telescopes are provided all three test beam areas precise tracking reference without time stamping, triggered readout of > 115 $\mu$s. If highest ava...

We report the morphological and compositional characteristics and their effect on optical properties of Er-doped GaN grown by solid source molecular beam epitaxy on sapphire and hydride vapor phase epitaxy GaN substrates. The GaN was grown by molecular beam epitaxy on sapphire substrates using solid sources ~for Ga, Al, and Er! and a plasma gas source for N2. The emission spectrum of the GaN:Er...

A new Raman spectrometer has been developed that can produce a complete high-resolution gas-phase vibrational spectrum during the time period of a single laser pulse. Conventional gas-phase Raman spectroscopy uses a single narrow-band laser to produce signals that are weak, requiring relatively long collection times. This spectrometer uses a degenerate OPO as a broad-band source that covers a c...

We report experimental observation of narrow-band coherent Cherenkov radiation driven by a subpicosecond electron bunch traveling along the axis of a hollow cylindrical dielectric-lined waveguide. For an appropriate choice of dielectric wall thickness, a short-pulse beam current profile excites only the fundamental mode of the structure, producing energetic pulses in the terahertz range. We pre...

Recently, many works have considered a physical properly of antenna in MIMO channel models, such as radiation pattern effective for MIMO system. However, effect of antenna for MIMO with different algorithms is required and also with different environments of signal behavior at each end of the link. Thus, a traditional antenna such as Omni-directional antenna generally is used to design MIMO sys...