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Fast ignition, a pivotal concept in inertial confinement fusion, presents a departure from conventional methods by implementing a two-stage process for fuel compression and ignition. This novel approach minimizes driver requirements and enhances energy efficiency. Among the primary solutions for initiating fast ignition, the utilization of light ion beams, specifically protons, generated through the interaction of high-power lasers with convertor foils, emerges as a prominent strategy. Investigation into the transport of alpha particles produced by the deuterium-tritium fusion reaction plays a vital role in the formation of a hot spot within the fast ignition framework. The self-heating effect caused by the energy deposition of alpha particles triggers ignition in the fusion fuel. Thus, this study focuses on exploring the impact of modern stopping power models, specifically BPS and MD, on the ignition criteria and hot spot formation of pre-compressed DT fuel using a two-temperature model in a non-equilibrium state. These new models are compared and contrasted with previous ones. For this investigation, a DT equimolar fuel with a density of 300 g cm–3 and an incident proton beam featuring an average energy of 4 MeV and a Maxwellian energy distribution are employed. Our calculations demonstrate that the newer BPS and MD stopping power models slightly shift the ignition criterion towards higher ρR values. Furthermore, the thermal efficiency reduction of alpha particles in these stopping power models leads to a significant decrease in hot spot temperature when compared to older models. [ABSTRACT FROM AUTHOR]

Focused Energy is a new startup company with the goal of developing laser-driven inertial fusion energy for electrical power production. The company combines the results from decades of fundamental research in inertial confinement fusion at universities and national laboratories with the flexibility and the speed of a startup company. Focused Energy has chosen the direct-drive, proton fast ignition approach to reach ignition, burn and high gain as the most promising approach. Located in Austin/US and Darmstadt/Germany, supported by the science community and private investment Focused Energy is paving the way to inertial fusion energy combining the best skill set and state-of-the-art technology from both sides of the Atlantic Ocean. In this paper we discuss the details and reasoning for the approach and the technical directions we have chosen. We will outline our roadmap for getting to a fusion pilot plant in the mid to late 2030s. [ABSTRACT FROM AUTHOR]

This paper investigates an analytical illustration of ignition conditions for the aneutronic reaction of proton-boron plasma in the presence of the magnetic field for fusion. In particular, the criterion for this plasma target is derived through two-temperature Lindl–Widner diagrams. Since the heating and cooling terms in the energy balance equation are affected by inequality between ions and electrons temperature combined with the impact of the magnetic field, the reduction of energy loss as well as the areal density parameter will increase the fusion rate. It will also relax the requirements of ignition conditions. Therefore, numerical derivations of ignition conditions at stagnation are performed involving the energy balance equation. The additional parameter applied other than electron and ion temperature as well as areal density is the magnetic field dependent B/ρ. It is shown that as B/ρ develops the required areal density decreases. For ions temperature of Ti < 1000 keV and electrons temperature of Te < 110 keV, the equation has real solutions for the areal density of ρR < 6 g/cm2. Furthermore, it is shown that the B/ρ parameter can be set at approximately 106 G cm3/g value. It shows the magnetic field has more effect than DT case and can reduce the driver requirements significantly. A comparison of this model with DT magnetized case shows that this model of p11B fuel is intermediate between experimental results of p11B non-magnetized and DT magnetized in the two-temperature model. [ABSTRACT FROM AUTHOR]

The effects of different nuclear reactions on thermonuclear burn-up conditions of equimolar mixture of deuterium–tritium are investigated. The minimum requirements are determined by three parameters: fuel initial density, initial temperature and hot spot size. The four-temperature theory is used to calculate the critical burn-up parameter or the product of the initial density and the minimum hot spot radius. It was shown that by considering the effect of all nuclear reactions, attaining the minimum conditions required for beginning of nuclear ignitions is faster than those cases in which the effect of reactions is considered individually. [ABSTRACT FROM AUTHOR]

Over the years the author has written, coordinated, or contributed to numerous reviews of fusion energy. In revisiting them, he is encouraged by the tremendous progress that has been made across the board. Nevertheless, while he believes that a viable fusion reactor could be made in both magnetic and inertial fusion energy, he doesn't think the best approach has yet been identified in either area. Also there remain a number of critical, hardly-explored areas. The author identifies three key issues. Finally, he comments briefly on all the major confinement approaches. [ABSTRACT FROM AUTHOR]

We investigate the efficiency of inertial fusion target compression, where at the initial time moment the thermonuclear fuel is in a two-phase state and has the form of two adjacent layers - the external DT-liquid layer and the internal DT-ice layer. We study this problem for the fast ignition targets, where the ultimate final density of the thermonuclear matter is of a special importance. We take the simplest type of a fast ignition target, which corresponds to the technical justification of the HiPER Project aimed at demonstrating fast ignition at the compressing laser pulse energy ~100 kJ. Such a target presents a spherical DT-ice shell coated with a thin polymer film. We obtain the dependence of the final target density on the mass fraction of the DT-matter liquid phase and formulate the requirements on the admissible concentration of liquid phase if the decrease in the DT-fuel final density does not exceed 10%. We find the criterion for choosing the laser-pulse duration which provides the minimum decrease in the final density of the target containing DT-matter in the initial two-phase state. [ABSTRACT FROM AUTHOR]

Intense ion beams from accelerators are now available to generate high energy density matter and to study astrophysical phenomena in the laboratory under controlled and reproducible conditions. A detailed understanding of interaction phenomena of intense ion- and laser radiation with matter is important for a large number of applications in different fields of science, extending from basic research of plasma properties to application in energy science and the investigation of processes occurring in stellar atmospheres or even in the interior of stars and planets. Energy loss processes of heavy ions in plasma and cold matter are important for the generation of high energy density states in general and especially in the hot dense plasma of an inertial fusion target. Of special interest are phase transitions and the associated time scales when matter passes the warm dense matter regime of the phase diagram at high density but relatively low temperature. We present an overview on recent results and developments of beam plasma, and beam matter interaction processes studied with heavy ion beams and laser beams combined with accelerator and nuclear physics technology. A natural example of hot dense plasma is provided by our neighbouring star the sun, and allows a deep insight into the physics of fusion, the properties of matter at high energy density, and is moreover an excellent laboratory for astroparticle physics. As such the sun’s interior plasma can even be used to probe the existence of novel particles and dark matter candidates with a combination of equipment and methods from accelerator technology and high resolution plasma spectroscopy. [ABSTRACT FROM AUTHOR]

The 2002 Fusion Summer Study was conducted July 8–19, 2002, in Snowmass, CO, and carried out a critical assessment of major next steps in the fusion energy sciences program in both magnetic fusion energy (MFE) and inertial fusion energy (IFE). The conclusions of this study were based on analysis led by over 60 conveners working with hundreds of members of the fusion energy sciences community extending over eight months. This effort culminated in two weeks of intense discussion by over 250 U.S. and 30 foreign fusion physicists and engineers present at the 2002 Fusion Summer Study. This is the Executive Summary of the study report. Details are posted at http://web.gat.com/snowmass [ABSTRACT FROM AUTHOR]

This paper was prepared for the Fusion Power Associates workshop on Cost Effective Steps to Fusion Power, 25–27 January 1999, and summarizes the role of IFE target fabrication, injection and tracking must play in pursuing a cost effective development program for inertial fusion energy that will lead to a cost effective fusion power plant. [ABSTRACT FROM AUTHOR]

This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the first structural wall from fusion pulses. This protective fluid or granular bed also moderates and absorbs most neutrons before they reach the first structural wall. Although the protective fluid activates, most candidate fluids have low activation hazard. Hands-on maintenance seems practical for the driver, target factory, and secondary coolant systems; remote maintenance is likely required for the reaction chamber, primary coolant, and vacuum exhaust cleanup systems. The driver and fuel target facility are well separated from the main reaction chamber. [ABSTRACT FROM AUTHOR]

There are several topics that require resolution prior to the construction of an Inertial Fusion Energy [IFE] laboratory Engineering Test Facility [ETF]: a pellet that produces high gain; a pellet fabrication system that cost-effectively and rapidly manufactures these pellets; a sufficiently uniform and durable high repetition-rate laser pellet driver; a practical target injection system that provides accurate pellet aiming; and, a target chamber that will survive the debris and radiation of repeated high-gain pellet implosions. In this summary we describe the science issues and opportunities that are involved in the design of a successful high gain direct drive Inertial Confinement Fusion [ICF] pellet. [ABSTRACT FROM AUTHOR]