Fusion Next Step

The link from lipid properties to mechanical properties of the bilayers is now feasible within the SCF approach. The next step is to understand the phase behaviour of the lipid systems. It is likely that large-scale (3D) SCF-type calculations are needed to prove the conjectures in the field that particular values of the Helfrich parameters are needed for processes like vesicle fusion, etc. In this context, it may also be extremely interesting to see what happens with the mechanical parameters when the system is molecularly complex (i.e. when the system contains many different types of molecules). Then there will be some hope that novel and deep insights may be obtained into the very basic questions behind nature s choice for the enormous molecular complexity in membrane systems. 

Once inter-species fusion was shown to be possible, the next step was an attempt to fuse myelomas with normal B lymphocytes. Only in 1975 did Kohler and Milstein propose a protocol that led to the efficient production of hybrid cells for the secretion of mAbs with a predetermined specificity, which could be perpetuated in cell cultures, the so-called hybridomas (Kohler, 1981). 

The requirements for long pulse operation in the next step fusion device ITER and beyond, like acceptable power exhaust, peak load for steady state, transient loads, sufficient target lifetime, limited long term tritium retention in wall surfaces, acceptable impurity contamination in central plasma and efficient helium exhaust, depend on complex processes. The input to the numerical codes, which are used for the optimization of divertor and wall components, relies to a large extend on our understanding of the major processes related to erosion and deposition, tritium retention, impurity sources and erosion processes. The reliability of predictions made with these codes depends crucially on the accuracy of the atomic and plasma-material interaction data available. 

Because of this, the Type I ELMy H-mode regime has been chosen as the reference operating regime for high fusion gain experiments in next step devices, such as ITER and FIRE [23], despite the drawbacks associated with the large energy and particle fluxes on the PFCs inherent to the Type I ELMs themselves. 

The quantitative analysis of the experimental measurements during ELMs and the modeling of ELM-caused erosion in present and next step fusion devices require an extension of the material and atomic physics database towards parameters and processes which are relevant for these conditions, such as ... 

Next-step D-T burning fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER), will require several kilograms of tritium [1,2]. While most of the tritium will be contained in the fuel process loop, the interaction of the plasma with plasma-facing components (first-wall armour, limiters, and divertors) will lead to accumulation of tritium in the torus. Based on the amounts and distribution of D retention in TFTR and... 

G. Federici, C.H. Skinner, J.N. Brooks, J.P. Coad, C. Grisolia, A.A. Haasz, A. Hassanein, V. Philipps, C.S. Pitcher, J. Roth, W.R. Wampler, D.G. Whyte, Plasma-material interactions in current tokamaks and their implications for next-step fusion reactors, Nucl. Fusion 41 (2001) 1967... 

Despite great strides, the problems arising from plasma-material interactions (PMIs), together with the selection of plasma facing materials, still represent major challenges for the reliable and safe operation of a D-T next-step tokamak [1]. They also remain potential obstacles for the successful development of future fusion power reactors. These issues came into sharp focus during D-T operation of the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) and, in particular, in the process of designing ITER. 

Tritium is a very sensitive subject for public acceptance of fusion and will play a central role in the operation of a next-step experimental fusion facility, which will routinely use large amounts of tritium as fuel (e.g., 100 times more in ITER than in present experiments) in a mixture with deuterium. Tritium retention is a regulatory issue since the amount that can potentially be released in an accident sets the limits on plasma operation without removal. Fuel economy has never been an issue in deuterium-fuelled experiments and only recently have the limitations associated with the use of tritium, and its incomplete recovery in experiments in TFTR and in JET, brought the issue of fuel retention under closer scrutiny [56,57]. Table 12.3 provides a list of key quantities related to tritium in existing tokamaks and a next-step device [18,57-59]. 

C. Skinner, G. Federici,Tritium issues in next step devices, International Conference on Advanced Diagnostics for Magnetic and Interial Fusion, Varenna, Italy, Sept 3-7, 2001... 

The first step of fieeze drying is atomization, which was discussed in Section 8.2. The next step is solidification, which is discussed in the book Transport Phenomena in Metallurgy [9]. The solidification or freezing time for a droplet of volume, V, and surfece area. A, is given by the time, t, required to transfer the heat of fusion from the fluid to the freezing droplet ... 

The next step is to add the fusion-inducing component, such as a salt solution, DNA, or another kind of liposome/membrane/cell, while continuously recording the fluorescence (Tf). The ratio of this component to the lipid vesicles or particles will vary according to the experimental goals. Similar to anionic liposomes, such as phosphatidylserine/phosphatidylcholine (PS/PC) which fuse rapidly in the... 

The Next Step, a term used to describe fusion devices which will be built... 

Eckstein W, Urbassek HM (2007) Computer simulation of the sputtering process in Sputtering by Particle Bombardment IV . In Behrisch R, Eckstein W (eds) Topics in applied physics, vol 110. Springer, Berlin, pp 21—31 EFDA (2005) Final report on conceptual power plant study, EFDA report EFDA-RP-RE-5.0 Erckmann W et al (2007) Fusion Sci Technol 53 279 Federici G, Skinner CH, Brooks JN, Coad JP, Grisolia G, Haasz AA, Hassanein A, Philipps V, Pitcher GS, Roth J, Wampler WR, Whyte DG (2001) Plasma-material interactions in current tokamaks and their implications for next step fusion reactors. Nucl Fusion 41 1967-2137... 

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