Boundary layer measurements during density clamp in DITE

Erents, S.K.; Fielding, S.J.; Hugill, J.; McCracken, G.M.; Proudfoot, G.

doi:10.1088/0029-5515/23/7/006

Cited by 4 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A correlation between energy and particle confinement times has been noted previously. It has been suggested that convective flow in the scrape-off layer, coupling the heat and particle fluxes parallel to the magnetic field, ensures that a decreased energy confinement time produces a decreased particle confinement time [24]. This link could be broken by increased edge radiation or by the production of a collisional boundary layer [11].…”

Section: Discussionmentioning

confidence: 99%

The effects of varying wall conditions, minor and major radii on confinement properties in ISX-B

et al. 1985

View full text Add to dashboard Cite

The Impurity Study Experiment (ISX-B) data base from which the energy confinement time scaling was derived for neutral-beam-heated discharges has been enlarged. Results obtained by using a non-gettered vacuum vessel and different minor and major radii are now included. Energy confinement times improve and a density dependence is introduced, if gettering is not employed. There is an associated increase in impurity radiation. A comparison of confinement properties obtained by using two minor radii (∼ 19 cm and the usual ∼ 26 cm) has been made. The correlation between radiation level and confinement is always found. No dependence of energy confinement on the minor radius is found. The confinement changes associated with wall conditions and radiation levels can be reproduced by using a gettered vessel and small plasma position displacements. In particular, outward radial displacements toward a limiter at the outer equator improve confinement. In this case, any radiation increase is small.

show abstract

Section: Discussionmentioning

confidence: 99%

The effects of varying wall conditions, minor and major radii on confinement properties in ISX-B

et al. 1985

View full text Add to dashboard Cite

show abstract

“…Poloidal divertor programmes on a large scale have operated on PDX [250], ASDEX [128], and D III [251], following the more modest feasibility studies on T-12 [252] and DIVA [253, 254], and a poloidal divertor is planned for JT-60. A bundle divertor has been tested on DITE [255], and an upgraded version of this device is now operational [256]. Tests of a toroidal divertor have also begun recently [257].…”

Section: Active Impurity Controlmentioning

confidence: 99%

Impurities in tokamaks

Isler

1984

Nucl. Fusion

183

View full text Add to dashboard Cite

Impurities continue to be a concern for future fusion devices, and ongoing efforts are made to study their generation, confinement, and control. Techniques for analysis of concentrations, power losses, and confinement of impurities are surveyed, and experimental examples illustrating typical observations in tokamak plasmas are presented. The use of impurities for diagnosing plasma properties is outlined briefly.

show abstract

“…For the study of plasma parameters in the scrapeoff layer in tokamaks, classical Langmuir probes have increasingly been applied [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. We had the opportunity to use this method for time resolved measurements of the plasma density and the electron temperature in the limiter shadow of T-10 during a prolonged period of operation in which the limiter configuration was varied over a wide range [24].…”

Section: Introductionmentioning

confidence: 99%

“…17. Power flux determined density limit: The power flux, p rec , necessary for recycling and total power P rec for T-10-like parameters (a = 0.32 m, R = 1.5 m, D L = 0.4 m 2 -s~l, \ 2 = 4 X 10~2 1 m 3 ) as a function of density (see Eqs(14) and (15)).…”

mentioning

confidence: 99%

Langmuir probe measurements in the limiter shadow of T-10: Non-linear scaling of edge density with central plasma density

et al. 1986

View full text Add to dashboard Cite

In the aperture limiter shadow of the T-10 tokamak, the temporal evolution of plasma density and electron temperature during single discharges is studied by using a Langmuir double probe. It is observed that the plasma of the scrape-off layer (SOL) passes through a stationary phase when the Ohmic heat input Uloop Ip also does, suggesting that the stationarity of the SOL is correlated with the stationarity of the discharge power balance. During this stationary phase the plasma density at the aperture limiter edge was found to be approximately proportional to the square of the line averaged core plasma density. – It is shown in the paper that this quadratic density scaling can be easily understood within the framework of a stationary particle balance model of the recycling process, i.e. the interaction of plasma and neutral particles of the working gas in the edge region. Quadratic density scaling is expected to hold generally if the plasma density is high enough to prevent the neutrals from reaching the centre. For high densities, on the other hand, there is a density limit defined by the requirement that the discharge should supply enough power to sustain recycling.

show abstract

Boundary layer measurements during density clamp in DITE

Abstract: In an Ohmically heated tokamak discharge with low Z e ff values, it is well known that plasma equilibrium requires that the electrostatic force within a magnetic

Cited by 4 publications

References 11 publications

The effects of varying wall conditions, minor and major radii on confinement properties in ISX-B

The effects of varying wall conditions, minor and major radii on confinement properties in ISX-B

Impurities in tokamaks

Langmuir probe measurements in the limiter shadow of T-10: Non-linear scaling of edge density with central plasma density

Contact Info

Product

Resources

About