This simulation that is based on input file used in the study of the neoclassical scaling of the H-mode pedestal width. The initial conditions for the plasma temperatures and density is set by analytical expressions with the plasma density of 
Several single particle simulation has been run with different time step. The energy is preserved within 2% in the simulation for 200 ion transient times only when the time step is about 1e-3 of ion transient time (sml_dt=1.d-3). Figures below show energy as function of time
sml_dt=0.02
sml_dt=0.005
sml_dt=0.002
sml_dt=0.001
In these single particle simulations, the computation time with the FMCFM interface (fm_use=1)
real 20m15.682s
user 19m57.207s
sys 0m6.028s
is compared with the corresponding simulation without the FMCFM interface (fm_use=0)
real 2m0.557s
user 1m55.979s
sys 0m3.632s
Updated version of the XGC-0 code that includes recent additions from Gunyoung Park is used for this simulation. The new version of XGC- inludes:
The electron temperature is slightly lower in the SOL region comparing to the electron temperature in the case XGC-222.
In order to give time for the radial electric field to develop, the use of MMM95 module through the FMCFM interface is delayed by 1000 time steps. Particle and thermal diffusivities from tbl namelist were used during the first 1000 time steps.
There are relatively small changes for the plasma density profile; electron temperature profile looks more realist.
Overall summary: There is insufficient flow shear stabilization for the particle transport in the inner pedestal region. The next thing to try is the updated sheath potential and radiation models provided by Gunyoung Park.
Four equilibria that represent plasma current scan has been provided by Rich Groebner. The readme file that came with the eqdsk files describes these discharges as follows
Jan 22, 2010
This directory contains DIII-D eqdsks from and experiment performed
March 4, 2008. This experiment had discharges which covered a range of
plasma currents, toroidal fields and plasma triangularities. The following
discharges were part of a four point current scan (0.5-1.5 MA) at a constant
toroidal magnetic field (2.1T) and at a constant shape (average triangularity
0.55). These discharges were run at an approximately constant normalized
toroidal beta (beta_n ~ 2.1-2.4). The pedestal temperature and density were
not constant in the scan.
The list of shots and currents for the eqdsks in this directory. These are
the eqdsks that were used for the ONETWO analysis as part of the profiles.py
analysis, used to generate beam pressure profiles in the analysis. The
g-eqdsks are from: /u/groebner/analysis/exps/2008/theory_test/python4.
The a-eqdsks were obtained from mdsplus with the writea.pro IDL procedure.
These eqdsks were earh run at the time of a specific Thomson laser pulse.
The fitting model used for the eqdsks allows for a finite edge current,
but the current density and pressure profiles should not be taken as anywhere
close to the experimental values. These eqdsks were used for purposes of
mapping experimental data on magnetic flux coordinates.
shot # Ip (MA) EFIT runid EFIT time
132016 1.50 EFIT04 3023
132014 1.17 EFIT04 3023
132017 0.85 EFIT04 2998
132018 0.51 EFIT04 1948
Results from this experiment have been discussed in"
Snyder et al., Phys of Plasmas 16 (2008) 056118
Groebner et al., NF 49 (2009) 085037
The discharges are analyzed with the TEQ equilibrium solver in the Caltrans code. Results of the analysis are to be published on the DIII-D analysis webpage. The TEQ code shows relatively high residuals for the GS solution in the near separatrix region. These discrepancies between the EFIT and TEQ solutions need to be addressed in future.
Simulation with strongly reduced particle anomlous transport show expected slow evolution of plasma density profiles in the pedestal region (case XGC-220). There is still significant increase of the electron temperature in the SOL region.
Summary: There might be different ExB flow shear effects for the particle and thermal transport
Case XGC-219 has the same input as case XGC-216 but uses an improved expression for the ExB flow shear rate.
The ExB flow shear rate has been implemented as simple derivative of the radial electric field with respect to minor radius:
New implementation is according to Ref. [T.S. Hahm and K.H. Burrell Phys. Plasmas 2, 1648 (1995)]:
where 
The FMCFM interface is modified and particle diffusivity is updated for this case with tbl_d_coeff_in;:
fm_ion_diff_norm%particle(i) = tbl_d_coeff_in * fm_norm_diff
The particle diffusivity in the core region is selected to be 
The fm_wexb coefficient has been increased from 1e-6 to 1e-4. This factor determines the effect of ExB flow shear suppression on the anomalous transport:
