4.18. SMITER-PFCFLUX benchmark ‘ELM case of ICRH optimized equilibrium on FWPs’¶
In this section the ELM heat loads are estimated with SMITER to the first wall panels 8-18 in the plasma configuration optimized for the ICRH coupling. The cases with the outboard midplane first separatrix shifted outwards by 4, 6, 8 and 10 cm with respect to the separatrix in the current QDT=10 H-mode reference equilibrium are present. This study was first done by Martin Kocan, reported in Heat loads to the ITER first-wall panels for the ICRH-optimized plasma equilibrium [DML5YK].
[DML5YK] | Martin Kocan et al, ITER_IDM_DML5YK |
In this report, baseline plasma equilibrium was taken. The heat loads to the outboard FWPs in the Baseline configuration are significantly below the FWP design limit, the cases presented in the report study the effects of shifting the plasma OMP separatrix towards the ICRH antenna and outboard FWPs. The cases were made of the outward shift of 4, 6, 8 and 10cm with respect to the Baseline plasma separatrix. The inter-ELM heat fluxes were neglected in these studiess, and only controlled intermittent-ELMs are included.
4.18.1. Input data¶
4.18.1.1. Equilibrium¶
The equilibrium used in this report is EQDSK-G geqPullTo8cmDsep8cm_00000_RDHR.eqdsk. This is the alternative equilibrium of 15MA plasma of DT scenario at burn. The outer mid-plane of the inner separatrix in this magnetic configuration has radial coordinate 8.3m (i.e. it is more out compared with the separatrix of the nominal magnetic configuration). The distance between inner and outer separatrices at the outer mid-plane is 7cm. This equilibrium has a 10 cm shift with respect to the Baseline configuration. It was used in other studies and moved back respectively for shifts of 4, 6 and 8 cm.
The radii of the first and second separatrices for different shifts are shown in the table below.
Equilibrium | \(R_{sep1}[m]\) | \(R_{sep1}[m]\) | ||
---|---|---|---|
ICRH optimized, \(\delta_{OMP}=10cm\) | 8.304 | 8.373 | |
ICRH optimized, \(\delta_{OMP}=8cm\) | 8.284 | 8.353 | |
ICRH optimized, \(\delta_{OMP}=6cm\) | 8.264 | 8.333 | |
ICRH optimized, \(\delta_{OMP}=4cm\) | 8.244 | 8.313 | |
Baseline | 8.205 | 8.299 |
4.18.2. Setting up the SMITER case¶
The study ITER_IDM_DML5YK_benchmark
already contains target and
shadow meshes and no additional action needs to be taken here. The meshes are
- target_dml5yk
- shadow_dml5yk
In these SMITER cases, custom power deposition profile is specified to include ELMs (unlike prevoius studies where the power deposition profile was exponential or double exponential).
4.18.2.1. GEOQ parameters¶
In the SALOME Object browser in SMITER section under “7_5_MA_SU_OUTBORD” case, one can right click on either target object (surf_be) or shadow object (Bm_mesh_surf_be) and select Edit CTL.
Under beqparameters
one can observe following parameters
Parameter | Value | Description |
---|---|---|
beq_bdryopt | 9 | \(\psi_m=\psi_{ltr}\) Boundary based on nodes of geometry, outboard values are used for \(R_m,B_{pm}\) and \(B_m\) |
beq_psiref | -1.476 | Reference PSI value at outer midplane |
beq_fldspec | 3 | Use cylindrical coordinates |
beq_rmove | 0 | Equilibrium displacement in radial direction |
Note
Parameter beq_brdyopt
is used to determine how to
calculate value of flux at plasma boundary \(\psi_m\), and
where to evaluate values of \(R_{m}\), \(B_{pm}\) (and
\(B_{m}\)) used in power deposition formulae. The options to
specify are either PSIREF, which will calculate the flux at plasma
boundary based on limiter wall, given to SMITER, or any other float
value given by the user.
Equilibrium is shifted back to different positions with beq_rmove
.
4.18.2.2. HDSGEN parameters¶
Refer to general setting parameters for limiter cases for HDSGEN
.4.18.2.3. POWCAL parameters¶
Parameter | Value | Description |
---|---|---|
calculation_type | global | ‘global’ shadowing by fieldlines which may wrap around torus |
shadow_control | 1 | Enable shadowing |
power_loss | 5e6 | Power loss given in \(W\) |
power_split | 1 | power split ion to electron direction. |
decay_length | 0.026 | decay length in meters. |
more_profiles | .true. | Set to .true. to activate edgprofparameters. |
Note
The power loss and decay length are ignored later on in the computation, since we are specifying a custom profile.
Custom power deposition profile is defined in
edgprofparameters
. These parameters are
Parameter | Value | Description |
---|---|---|
coord_of_positions | ‘radius’ | Whether positions in distance or flux from SOL, the other option is thus ‘flux’ |
deposition_profile | vals | Array of deposition profile, values are separated by ‘,’ |
number_of_positions | 100 | Length of array of deposition profile |
positions | vals |
|
profile_formula | ‘samples’ | Set to .true. to activate edgprofparameters. |
Note
Note that the maximum number of positions
(number_of_position
) is 100. If bigger number is given, SMITER
wil throw an error.
The plot for ELM heat fluxes as a function of distance from the outer midplane separatrix is shown in Fig. 4.59.