Fusion device applications

During the last 25 years X-ray spectroscopy has been intensively developed for plasma diagnostics. Since the first application of X-ray spectrometers on the early fusion devices such as PLT and TFR, it has been used to determine basic plasma parameters such as the temperature of ions and electrons. It is now frequently being applied not only to low density plasmas in tokamaks and astrophysical objects [1], but also to laser-produced plasma [2]. It has been shown, that the precision of plasma parameters as obtained from X-ray spectroscopy is competitive to the standard methods for plasma diagnostics, such as Thomson scattering and charge exchange spectroscopy for electron and ion temperature, respectively [3]. 

F.L. Tabares, D. Tafalla, I. Tanarro, V.J. Herrero, A. Islyaikin, C. Maffiotte Suppresion of hydrogenated carbon film deposition by scavenger techniques and their application to the tritium inventory control in fusion devices. Plas. Phys. Contr. Fusion 44, L37 (2002)... 

There are automatic fusion devices for preparing samples for XRF, but most laboratories preparing a mixture of sample types still prefer a manual process. Because of various new features of XRF, the pressed disc technique, of mixing the ground sample with a binder and pressing in a die, is finding more application. Its use is discussed below. 

Before discussing the plasma-surface-interaction processes (PSI processes) in a MCF device, it is favorable to briefly discuss the most important microscopic processes. Note that these processes are basic in the sense that they occur whenever energetic or reactive species interact with solid surfaces. These processes are in no way restricted to PSI processes in a fusion device. For example, such processes are exploited in many technical plasma applications or occur in different kinds of ion-solid interaction. 

Refractory carbides, with their high chemical stability and low atcnnic number, are used in many experimental coatings for fusion devices. These materials must be able to withstand very severe thermal shock. The following applications have been reported P H l... 

Several companies manufacture syringe applicators which may be used in manual or automatic modes, such as Fisnar USA, Electron Fusion Devices EFD, Wentworth and Kent Moore (Fig. 5). 

The potential applications of SiC SiC composites currently considered are core components, especially the control rod sheath and cladding of the VHTR, GFR, SFR, MSR, and LFR. Because the scope of this chapter is restricted to the Generation IV system, only part of the nuclear applications of SiCf/SiC was described. However, SiC SiC composites are also considered as the in-vessel components of magnetic confinement fusion devices including blanket structures, flow channel inserts (FCI) for the liquid metal (LM) blankets, and plasma-facing components (PFCs) [88—91]. In addition, they are candidates for an advanced fuel cladding for LWRs as an ATF (accident tolerance fuel) concept [72,92—97] and a channel box for the BWRs (boiling water-cooled reactors) [96,98,99]. 

Applied Sciences, Inc. has, in the past few years, used the fixed catalyst fiber to fabricate and analyze VGCF-reinforced composites which could be candidate materials for thermal management substrates in high density, high power electronic devices and space power system radiator fins and high performance applications such as plasma facing components in experimental nuclear fusion reactors. These composites include carbon/carbon (CC) composites, polymer matrix composites, and metal matrix composites (MMC). Measurements have been made of thermal conductivity, coefficient of thermal expansion (CTE), tensile strength, and tensile modulus. Representative results are described below. 

Hermetically sealed electrical devices must be verified by a testing laboratory to meet mechanical abuse and to withstand aging and exposure to expected chemicals. Devices potted with common silicones and similar materials by an end user or even a manufacturer, without testing, and devices merely provided with O-rings seldom meet acceptable criteria. Normally, hermetically sealed devices must be sealed through metal-to-metal or glass-to-metal fusion. Many electrical relays, switches, and sensors are available as hermetically sealed devices for common oil and gas producing facility applications. Hermetically sealed devices are often desirable to protect electrical contacts from exposure to salt air and other contaminants. 

The ability of some plastic systems to do this may be useful in schemes for handling the radiation output of nuclear devices, including the radiation from the fusion power machines under development. Obviously the application is not for shielding, which the heavy metals do much better, but rather for an energy level reduction system that would convert the high energy radiation to forms which would be more useful in power distribution. 

Seekers of knowledge satisfy their curiosity about how the world and its organisms work, but the applications of science are not limited to intellectual achievement. The topics in Frontiers of Science affect society on a multitude of levels. Civilization has always faced an uphill battle to procure scarce resources, solve technical problems, and maintain order. In modern times, one of the most important resources is energy, and the physics of fusion potentially offers a nearly boundless supply. Technology makes life easier and solves many of today s problems, and nanotechnology may extend the range of devices into extremely small sizes. Protecting one s personal information in transactions conducted via the Internet is a crucial application of computer science. 

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