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The effect of safety factor profile on transport in steady-state, high-performance scenarios
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10.1063/1.3691646
/content/aip/journal/pop/19/3/10.1063/1.3691646
http://aip.metastore.ingenta.com/content/aip/journal/pop/19/3/10.1063/1.3691646

Figures

Image of FIG. 1.
FIG. 1.

(Color online) The time-averaged q-profiles of the scan endpoints are shown with uncertainties. The inset table shows the DIII-D discharge numbers for the scan, and the color-coding and line styles match the four plots shown. The same color-coding and line styles are used elsewhere when comparing other features of the scan endpoints.

Image of FIG. 2.
FIG. 2.

(Color online) Density and temperature profiles for the scan endpoints, using the same color-coding and line styles as in Fig. 1.

Image of FIG. 3.
FIG. 3.

(Color online) Magnitude of the derivative of with respect to the radial coordinate in keV/m, where is the toroidal flux and is the toroidal field, for the scan endpoints. broadens with increasing .

Image of FIG. 4.
FIG. 4.

(Color online) Profiles of for the three cases with . (This is the bottom row in the inset table in Fig. 1). Red-dashed is for , cyan-dotted is for , and black-solid is for . at mid-radius generally decreases with because decreases more with than does.

Image of FIG. 5.
FIG. 5.

(Color online) Profiles of and electron density for the three cases with . (This is the middle column in the inset table in Fig. 1). Red-dashed is for , cyan-dotted is for , and black-solid is for . In this data set, discharges typically have the largest mid-radius and highest density.

Image of FIG. 6.
FIG. 6.

(Color online) FIR scattering measurement of chord-averaged, low-k θ, density fluctuation root-mean-squared amplitude for the scan endpoints. Frequencies in the range of 50–500 kHz were used in the integration. (Including MHD modes by integrating from 7 kHz-500 kHz does not significantly alter the scaling with ). Online color-coding is the same as in Fig. 1. The times shown match the analysis time range used to generate the average profiles in previous figures.

Image of FIG. 7.
FIG. 7.

(Color online) Spectrograms from FIR scattering for a discharge with (top) and (bottom). Both have . White vertical lines denote the analysis time range for each. The spectrum of the discharge is broader and has less quasi-coherent mode activity.

Image of FIG. 8.
FIG. 8.

The power spectra for density fluctuations localized to from the beam emission spectroscopy diagnostic. The same discharges compared in Fig. 7 are shown. The approximate toroidal Alfvén eigenmode frequency in the plasma core is shown as a dashed vertical line for each.

Image of FIG. 9.
FIG. 9.

(Color online) The average thermal diffusivity profiles for all nine discharges in the scan are shown. The columns correspond to the different cases, and is identified using the color-coding and line styles shown. (: solid, : dotted, : dashed). Peak values are in the vicinity of , and significant variation with and is apparent, as described in the text.

Image of FIG. 10.
FIG. 10.

(Color online) (a) The maximum value of in the range is plotted versus . is identified by the color-coding and symbols shown. (b) The maximum value of in the range is plotted versus .

Image of FIG. 11.
FIG. 11.

(Color online) (a) is plotted versus . is identified by the color-coding and symbols shown. (b) is plotted versus .

Image of FIG. 12.
FIG. 12.

(Color online) (a) Power transported by the electron fluid through conduction and convection from the total plasma volume is plotted versus . is identified by the color-coding and symbols shown. (b) Power lost by ions through conduction and convection from the total plasma volume is plotted versus .

Image of FIG. 13.
FIG. 13.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each is plotted for three discharges with . The local quench rate is shown as a horizontal line, and its uncertainty is typically (not shown). In the low-k θ range, an ion mode is the most unstable for all three discharges. (: solid lines, : dotted lines, and : dashed lines).

Image of FIG. 14.
FIG. 14.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each are plotted for three discharges with . (: solid lines, : dotted lines, and : dashed lines).

Image of FIG. 15.
FIG. 15.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each are plotted for three discharges with . (: solid lines, : dotted lines, and : dashed lines).

Image of FIG. 16.
FIG. 16.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each are plotted for three discharges with . The local quench rate is shown as a horizontal line, and its uncertainty is typically (not shown). (: solid line, : dotted line, and =1: dashed line).

Image of FIG. 17.
FIG. 17.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each are plotted for three discharges with . (: solid line, : dotted line, and : dashed line).

Image of FIG. 18.
FIG. 18.

(Color online) TGLF linear stability analysis results at : the growth rate and frequency of the most unstable mode at each are plotted for three discharges with . (: solid line, : dotted line, and : dashed line).

Image of FIG. 19.
FIG. 19.

(Color) Sensitivity of the TGLF low-k θ growth rates at for the , case to . The experimental is shown by red *. The was adjusted as input to TGLF to recalculate the growth rate. Growth rates at several values of are shown that are near the peak in the low-k θ growth rate spectrum. This calculation is based on only a single time slice that has experimental profiles close to the average profiles of the same discharge. The experimental quench rate is shown as a horizontal dashed line, and the vertical dashed lines denote one standard deviation of the experimental .

Image of FIG. 20.
FIG. 20.

(Color) Same plot as in Fig. 19 but for the and case.

Image of FIG. 21.
FIG. 21.

(Color) Measured (solid, with error bars) and TGLF predicted (dashed) electron and ion temperature profiles are compared for the scan endpoints.

Tables

Generic image for table
Table I.

Summary of transport trends with q-profile changes.

Generic image for table
Table II.

Time averaged values at of , , , and the quench rate (kHz) for the nine discharges analyzed in this study.

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/content/aip/journal/pop/19/3/10.1063/1.3691646
2012-03-09
2014-04-20
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752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: The effect of safety factor profile on transport in steady-state, high-performance scenarios
http://aip.metastore.ingenta.com/content/aip/journal/pop/19/3/10.1063/1.3691646
10.1063/1.3691646
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