ISSN:0863-1042    

DOI:10.1002/ctpp.2150280412

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractLangmuir probes mounted in an antenna protection tiles have facilitated the comprehensive measurement of electron temperatures and densities in the JET scrape‐off layer (sol)2. The probes are close to the outside midplane and at radial positions of 15 and 28 mm behind the last closed flux surface. The data are from ohmic discharges with plasma currents between 1 and 5 MA and average electron densities between 8 × 1018and 5 × 1019m−3.Here we use these measurements in a simple diffusive model for the electrons to obtain empirical scalings of the transport coefficients with local parameters. The scalings are shown to be inconsistent with exponentially decaying profiles of electron temperature and density, such as are measured in the JET sol.In the apparent absence of a suitable model we are forced to scale directly the characteristic decay lengths in similar fashion. Finaally we use these dependences to campare models of global particle and power balance with the

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280413

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280414

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280415

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280416

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractIn the first part of this paper we present multifluid model calculations of marfe instabilities in a simple geometry. Assuming carbon as the dominant impurity, the time evolution of the 2D Marfe is followed and typical e‐folding times and their variation with the poloidal and radial heat conductivities are determined. In part two of this paper we present a scrape‐off layer simulation in a typical x‐point geometry using a simplyfied hydrogen recycling model and again carbon as impurities. Other impurity species can be treated as

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280417

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractA fluid model which includes ion drifts has been applied to the SOL of a tokamak with a poloidal divertor. Large parallel velocities and steep gradients in the pressure and electrostatic potential are found near the X‐point, in contrast with the solutions of the standard mode

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280418

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe one‐dimensional hydrodynamic code SOLID coupled with the two‐dimensional Monte Carlo neutral gas code DEGAS are used to simulate the scrape‐off layer and divertor recycling region of the ASDEX tokamak. A numerical data base is created for the relevant parameter regime and compared to the limited amount of experimental data. A reasonable fit with ohmic data is obtained, assuming classical heat flow along field lines and allowing for varying divertor saturation. The problem of experimental errors on one side and deficiencies in the theoretical model on the other side are disc

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280419

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280420

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe high recycling mode of divertor operation is found to depend on the spatial temperature gradient along the divertor length falling within limits set by the ratio of collision frequency with respect to ionization rate. An analytic expression for the neutral particle density necessary to sustain this mode is at least an order of magnitude greater at the divertor throat than previously assumed.

ISSN:0863-1042    

DOI:10.1002/ctpp.2150280421

出版商:WILEY‐VCH Verlag    

年代:1988

数据来源: WILEY