Power density

About: Power density is a research topic. Over the lifetime, 9534 publications have been published within this topic receiving 197264 citations. The topic is also known as: volumic power & volume power density.

Amplified spontaneous emission in active channel waveguides produced by electron-beam lithography in LiF crystals

Abstract: In this letter we report the observation of amplified spontaneous emission of the red light from LiF:F2 centers in active channel waveguides realized by electron-beam lithography in lithium fluoride crystals. Low pumping power densities have been used in quasi-continuous-wave regime at room temperature; the appreciable values of the gain coefficients, 4.67 cm−1 with an exciting power density of 0.31 W/cm2 at 458 nm, make this material a good candidate for the realization of active integrated optical devices.

A parametrically excited vibration energy harvester

Abstract: In the arena of vibration energy harvesting, the key technical challenges continue to be low power density and narrow operational frequency bandwidth. While the convention has relied upon the activation of the fundamental mode of resonance through direct excitation, this article explores a new paradigm through the employment of parametric resonance. Unlike the former, oscillatory amplitude growth is not limited due to linear damping. Therefore, the power output can potentially build up to higher levels. Additionally, it is the onset of non-linearity that eventually limits parametric resonance; hence, this approach can also potentially broaden the operating frequency range. Theoretical prediction and numerical modelling have suggested an order higher in oscillatory amplitude growth. An experimental macro-sized electromagnetic prototype (practical volume of ~1800 cm3) when driven into parametric resonance, has demonstrated around 50% increase in half power band and an order of magnitude higher peak power density normalised against input acceleration squared (293 mW cm23 m22 s4 with 171.5 mW at 0.57 m s22) in contrast to the same prototype directly driven at fundamental resonance (36.5 mW cm23 m22 s4 with 27.75 mW at 0.65 m s22). This figure suggests promising potentials while comparing with current state-of-the-art macro-sized counterparts, such as Perpetuum’s PMG-17 (119 mW cm23 m22 s4).

Achievement of the highest performance of a CCMHD generator: an isentropic efficiency of 63% and an enthalpy extraction ratio of 31%

Abstract: In this paper we describe the highest-performance closed-cycle magnetohydrodynamic (CCMHD) power generator driven by a shock-tube. Despite the use of a small-scale device having a power-generating volume of approximately 4 liters, outstanding performance, namely, the isentropic efficiency of 63%, the enthalpy extraction ratio of 30.8%, the electrical power output of 1.23 MW, and the power density of 297 MW/m/sup 3/, is achieved at the stagnation temperature of 2250 K and the applied magnetic flux density of 3.0 T. The following facts contribute to the world's highest performance of the CCMHD power generator: a less-divergent generator shape; the employment of cesium-seeded helium gas; the introduction of an inlet swirl; and the production of homogeneous plasma.

URGENT−A computer program for calculating undulator radiation spectral, angular, polarization, and power density properties

Abstract: A computer program, URGENT, is described that allows efficient calculation of the main properties of undulator radiation (spectral, angular, polarization, power density), including the effects of electron beam emittance and finite collection angles, for ideal plane, elliptical or helical trajectories, and also for the crossed‐undulators scheme.