다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The major increase in discharge duration and plasma energy in a next step DT fusion reactor will give rise to important plasma-material effects that will critically influence its operation, safety and performance. Erosion will increase to a scale of several centimetres from being barely measurable at a micron scale in today's tokamaks. Tritium co-deposited with carbon will strongly affect the operation of machines with carbon plasma facing components. Controlling plasma-wall interactions is critical to achieving high performance in present day tokamaks, and this is likely to continue to be the case in the approach to practical fusion reactors. Recognition of the important consequences of these phenomena stimulated an internationally co-ordinated effort in the field of plasma-surface interactions supporting the Engineering Design Activities of the International Thermonuclear Experimental Reactor project (ITER), and significant progress has been made in better understanding these issues. The paper reviews the underlying physical processes and the existing experimental database of plasma-material interactions both in tokamaks and laboratory simulation facilities for conditions of direct relevance to next step fusion reactors. Two main topical groups of interaction are considered: (i) erosion/redeposition from plasma sputtering and disruptions, including dust and flake generation and (ii) tritium retention and removal. The use of modelling tools to interpret the experimental results and make projections for conditions expected in future devices is explained. Outstanding technical issues and specific recommendations on potential R&D avenues for their resolution are presented.

/pdf/plasma-material-interactions-in-current-tokamaks-and-their-1a6iwv89x6.pdf

Plasma{material interactions in current tokamaks and their implications for next step fusion reactors

Improved performance in a photovoltaic device made of colloidal quantum dots is achieved through a combination of passivation by halide anions and organic crosslinking.

/pdf/hybrid-passivated-colloidal-quantum-dot-solids-24inf74xv3.pdf

Hybrid passivated colloidal quantum dot solids

Progress, since the ITER Physics Basis publication (ITER Physics Basis Editors et al 1999 Nucl. Fusion 39 2137–2664), in understanding the processes that will determine the properties of the plasma edge and its interaction with material elements in ITER is described. Experimental areas where significant progress has taken place are energy transport in the scrape-off layer (SOL) in particular of the anomalous transport scaling, particle transport in the SOL that plays a major role in the interaction of diverted plasmas with the main-chamber material elements, edge localized mode (ELM) energy deposition on material elements and the transport mechanism for the ELM energy from the main plasma to the plasma facing components, the physics of plasma detachment and neutral dynamics including the edge density profile structure and the control of plasma particle content and He removal, the erosion of low- and high-Z materials in fusion devices, their transport to the core plasma and their migration at the plasma edge including the formation of mixed materials, the processes determining the size and location of the retention of tritium in fusion devices and methods to remove it and the processes determining the efficiency of the various fuelling methods as well as their development towards the ITER requirements. This experimental progress has been accompanied by the development of modelling tools for the physical processes at the edge plasma and plasma–materials interaction and the further validation of these models by comparing their predictions with the new experimental results. Progress in the modelling development and validation has been mostly concentrated in the following areas: refinement in the predictions for ITER with plasma edge modelling codes by inclusion of detailed geometrical features of the divertor and the introduction of physical effects, which can play a major role in determining the divertor parameters at the divertor for ITER conditions such as hydrogen radiation transport and neutral–neutral collisions, modelling of the ion orbits at the plasma edge, which can play a role in determining power deposition at the divertor target, models for plasma–materials and plasma dynamics interaction during ELMs and disruptions, models for the transport of impurities at the plasma edge to describe the core contamination by impurities and the migration of eroded materials at the edge plasma and its associated tritium retention and models for the turbulent processes that determine the anomalous transport of energy and particles across the SOL. The implications for the expected performance of the reference regimes in ITER, the operation of the ITER device and the lifetime of the plasma facing materials are discussed.

/pdf/chapter-4-power-and-particle-control-3l68lj0fxw.pdf

Chapter 4: Power and particle control

SIMNRA is a Microsoft Windows 95/Windows NT program with fully graphical user interface for the simulation of non-Rutherford backscattering, nuclear reaction analysis and elastic recoil detection analysis with MeV ions. About 300 different non-Rutherford and nuclear reactions cross-sections are included. SIMNRA can calculate any ion-target combination including incident heavy ions and any geometry including transmission geometry. Arbitrary multi-layered foils in front of the detector can be used. Energy loss straggling includes the corrections by Chu to Bohr’s straggling theory, propagation of straggling in thick layers, geometrical straggling and straggling due to multiple small angle scattering. The effects of plural large angle scattering can be calculated approximately. Typical computing times are in the range of several seconds.

SIMNRA, a simulation program for the analysis of NRA, RBS and ERDA

This document describes the use of the program SIMNRA and the physical concepts implemented therein. SIMNRA is a MicrosoftWindows program for the simulation of backor forward scattering spectra for ion beam analysis with MeV ions. SIMNRA is intended for the simulation of spectra with Rutherford scattering cross-sections (RBS), non-Rutherford cross-sections (EBS), nuclear reactions (NRA), elastic recoil detection analysis (ERDA) with light and heavy incident ions, and medium energy ion scattering (MEIS). SIMNRA can calculate spectra for any ion-target combination including incident heavy ions and any geometry including backscattering, forward scattering, and transmission geometries. Arbitrary multi-layered foils in front of the detector and arbitrary multi-layered windows (such as exit windows for an external beam) in front of the sample can be used. Several different stopping power data sets are available. Energy loss straggling is calculated including the corrections by Chu and Yang to Bohr’s theory, energy loss straggling propagation in thick layers is taken into account. Additionally the effects of multiple small-angle and plural large angle scattering can be calculated approximately as well as surface and substrate roughness. Many non-Rutherford and nuclear reaction cross-sections for incident protons, deuterons, 3He-, 4He-, 6Liand 7Li-ions are included. Data fitting (layer thicknesses, compositions etc.) is possible by means of the Simplex algorithm. OLE automation allows automated analysis of large numbers of spectra and the development of new applications. SIMNRA supports the IBA data format (IDF) for data storage and exchange of data between different simulation programs. SIMNRA is easy to use due to the graphical Microsoft Windows user interface: SIMNRA makes full use of the graphics capacities of Windows. SIMNRA shell extensions extend the abilities of Windows Explorer and Windows Search, thus allowing a seamless integration of SIMNRA into the Windows system.

http://www2.if.usp.br/~lamfi/guia-simnra.pdf

SIMNRA user's guide

Deuterium retention in tungsten in dependence of the surface conditions

The ion-driven retention of deuterium in polycrystalline tungsten (PCW) is studied experimentally and theoretically as a function of temperature, incident ion energy, and ion fluence. Deuterium retention was investigated by thermodesorption spectroscopy and ion beam analysis. The peculiarities of deuterium behavior in PCW such as (i) ion-induced defect formation at low-energy implantation and (ii) higher D retention of low-energy ions (60–200eV) compared to high-energy ions (3keV) at high fluences are considered. The effect of intrinsic defects (dislocations, vacancies, grain boundaries) and ion-induced defects (vacancies, dislocations, deuterium clusters) is discussed for polycrystalline tungsten.

/pdf/ion-driven-deuterium-retention-in-tungsten-3994zitmon.pdf

Ion-driven deuterium retention in tungsten

SIMNRA is an analytical code for the simulation of ion beam analysis energy spectra obtained by Rutherford backscattering, non-Rutherford scattering, elastic recoil detection analysis, and nuclear reaction analysis. Improvements of the simulation physics in SIMNRA version 7 include among others the skewness of all energy spread distributions, improved handling of scattering or reaction cross-sections with structure, generalized layer roughness, and sample porosity.

M. Mayer

Papers

SIMNRA, a simulation program for the analysis of NRA, RBS and ERDA

SIMNRA user's guide

Deuterium retention in tungsten in dependence of the surface conditions

Ion-driven deuterium retention in tungsten

Improved physics in SIMNRA 7