Electric Power Amplification in Fusion Power Plants

Fusion power concepts that are heated by electrical devices for the purpose of producing high levels of electrical output are in effect electric power amplifiers. Three systems are considered: A hypothetical electric power version of the ITER experiment, the ARIES-1 fusion reactor design, and a modified version of ARIES-1 with stainless steel structural material. We find that an ITER power plant with a reasonable electric power conversion system would produce no net electric power at its target energy amplification factor of 10. The ARIES-1 conceptual power plant, as conceived, would have an energy amplification of 22 and an electric amplification of 6. If stainless steel were substituted for the SiC composite material assumed, the ARIES-1 electric power amplification would drop to roughly 3. We conclude that practical fusion power plants will likely require a near-ignition operating mode and qualified high temperature materials as prerequisites for commercial viability.

Understanding the Seeding Pulse-Induced Optical Amplification in N 2 + Pumped by 800 NM Femtosecond Laser Pulses

Nitrogen ions pumped by intense femtosecond laser pulses present an optical gain at 391.4 nm, evident by energy amplification of an injected resonant seeding pulse. We report a time-resolved measurement of the amplification process with seeding pulses having varying intensities. It is found that the amplification factor depends on the intensity of the seeding pulse and the effective temporal window for the optical gain becomes longer by applying more intense seeding pulses. These two features are in sharp contrast with classic pump-probe experiments, pinpointing the crucial role of macroscopic coherence and its dynamics during the lasing process. We further measure the temporal profile of the amplified emission for seeding pulse injected at different time delays. A complicated temporal behavior is observed, which highlights the nature of the superfluorescence.

Research on Local Sound Field Control Technology Based on Acoustic Metamaterial Triode Structure

Cell photoacoustic detection faces the problem where the strength of the sound wave signal is so weak that it easily gets interfered by other acoustic signals. A sonic triode model based on an artificial periodic structure is designed by COMSOL Multiphysics 5.3a software (Stockholm, Sweden), and software simulations are conducted. Experiments show that when a sound wave with a specific frequency is input by the sound wave triode, it can produce an energy amplification effect on the sound wave signals of the same frequency and a blocking effect on the sound wave signals of other frequencies. This contrast effect is more obvious after increasing the sound pressure intensity of the input sound wave signal. It can effectively filter out interference sound signals. The study of the acoustic triode model provides a new approach for the acquisition and identification of acoustic signals in cell photoacoustic detection, which can significantly improve the working efficiency and accuracy of cell photoacoustic detection.

A novel cleanliness control method for disk amplifiers

As the key part for energy amplification of high-power laser systems, disk amplifiers must work in an extremely clean environment. Different from the traditional cleanliness control scheme of active intake and passive exhaust (AIPE), a new method of active exhaust and passive intake (AEPI) is proposed in this paper. Combined with computational fluid dynamics (CFD) technology, through the optimization design of the sizes, shapes, and locations of different outlets and inlets, the turbulence that is unfavorable to cleanliness control is effectively avoided in the disk amplifier cavity during the process of AEPI. Finally, the cleanliness control of the cavity of the disk amplifier can be realized just by once exhaust. Meanwhile, the micro negative pressure environment in the amplifier cavity produced during the exhaust process reduces the requirement for sealing. This method is simple, time saving, gas saving, efficient, and safe. It is also suitable for the cleanliness control of similar amplifiers.

Implementation of Solar Power with Smart Grid

This paper focus on the work that is to explore Photovoltaic and Power Supply techniques in Smart Grid Energy Management. The research document also aims to foster an understanding of the concept and benefits of Smart Grid. The research work includes a comprehensive literature review to identify the key findings in the Sun Energy amplification range with Smart Grid Systems. As part of this research, Smart Grid's place has been described for spreading solar energy generation. Research work also aims to assess different ways to put the Smart Grid model into the Sun Energy exchange system, explaining Solar PV requirements for Smart Grid applications.

Low-frequency wave-energy amplification in graded two-dimensional resonator arrays

Energy amplification in square-lattice arrays of C-shaped low-frequency resonators, where the resonator radii are graded with distance, is investigated in the two-dimensional linear acoustics setting for both infinite (in one dimension) and finite arrays. Large amplifications of the incident energy are shown in certain array locations. The phenomenon is analysed using: (i) band diagrams for doubly-periodic arrays; (ii) numerical simulations for infinite and finite arrays; and (iii) eigenvalue analysis of transfer matrices operating over individual columns of the array. It is shown that the locations of the large amplifications are predicted by propagation cut-offs in the modes associated with the transfer-matrix eigenvalues. For the infinite array, the eigenvalues form a countable set, and for the low frequencies considered, only a single propagating mode exists for a given incident wave, which cuts off within the array, leading to predictive capabilities for the amplification location. For the finite array, it is shown that (in addition to a continuous spectrum of modes) multiple discrete propagating modes can be excited, with the grading generating new modes, as well as cutting others off, leading to complicated amplification patterns. The numerical simulations reveal that the largest amplifications are achieved for a single row array, with amplifications an order of magnitude smaller for the corresponding infinite array. This article is part of the theme issue ‘Modelling of dynamic phenomena and localization in structured media (part 1)’.

Resolvent-analysis-based design of airfoil separation control

We use resolvent analysis to design active control techniques for separated flows over a NACA 0012 airfoil. Spanwise-periodic flows over the airfoil at a chord-based Reynolds number of$23\,000$and a free-stream Mach number of$0.3$are considered at two post-stall angles of attack of$6^{\circ }$and$9^{\circ }$. Near the leading edge, localized unsteady thermal actuation is introduced in an open-loop manner with two tunable parameters of actuation frequency and spanwise wavelength. To provide physics-based guidance for the effective choice of these control input parameters, we conduct global resolvent analysis on the baseline turbulent mean flows to identify the actuation frequency and wavenumber that provide large perturbation energy amplification. The present analysis also considers the use of a temporal filter to limit the time horizon for assessing the energy amplification to extend resolvent analysis to unstable base flows. We incorporate the amplification and response mode from resolvent analysis to provide a metric that quantifies momentum mixing associated with the modal structure. This metric is compared to the results from a large number of three-dimensional large-eddy simulations of open-loop controlled flows. With the agreement between the resolvent-based metric and the enhancement of aerodynamic performance found through large-eddy simulations, we demonstrate that resolvent analysis can predict the effective range of actuation frequency as well as the global response to the actuation input. We believe that the present resolvent-based approach provides a promising path towards mean flow modification by capitalizing on the dominant modal mixing.

The pulsed subcritical amplifier of neutron flux driven by high-intensity neutron generator

The subcritical reactor driven by external neutron source could apply as useful instrument for modern nuclear energy applications requiring high-level irradiation of different materials by the high-energy and high-intense neutron flux (e. g., nuclear waste transmutation, radiopharmaceutical production, etc.). The propagation of neutron pulses through the subcritical nuclear system was considered in the present paper. Simple homogeneous subcritical systems and a model of two-zone subcritical reactor were computationally investigated using Monte Carlo MCNP4c transport code. The propagation of one initial neutron pulse and series of one hundred neutron pulses through the presented subcritical nuclear models were simulated. In this study, the neutron multiplication factor, the neutron flux, the energy amplification factor, the total energy of neutrons in initial pulse, etc. were obtained and analyzed. The presented calculations have shown that the considered pulse subcritical systems can be successfully used as effective amplifiers of neutron flux from the initial source. The modeling results indicate that there is an achievement of a stable, high level of neutron flux caused by the accumulation of delayed neutrons from previous pulses in series of one hundred pulses for both homogeneous and heterogeneous systems.