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TRANSP user meeting, JET, 11/01/2008
1
TORIC/TRANSP simulations of ICRH heating of JET plasmas
Summary of TORIC runs for JET (I. Voitsekhovitch) and discussion with TRANSP and ICRH experts (Yu. Baranov, J. Conboy, I. Jenkins,
T. Johnson, D. Keeling, E. Lerche)
Outline
1. Brief information about TORIC
2. TORIC namelist in TRANSP and TORIC related post-processing
3. Benchmarking of old and new TORIC versions
4. Benchmarking between TORIC and SPRUCE for minority heating
5. Fundamental D heating with TORIC
6. Mode Conversion simulations: comparison with TOMCAT & PION
TRANSP user meeting, JET, 11/01/2008
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What is TORIC?
TORIC is a FLR full wave code. It solves Maxwell’s equations in the presence of plasma and wave antenna. It does this with a fixed frequency and a linear plasma
response in a mixed spectral-finite element basis. The oscillating plasma current JP is considered as a moment of the perturbed particle distribution from the linearised
Boltzmann eq. in the presence of the electric field from the excited wave.
AP JJ
iE
cE
4
2
2
inimEE nm exp)(,
TORIC uses the FLR expansion to convert the vector integro-differential Maxwell equation with d/dt -i into a 6-order partial differential equation. This
approximation retains the 2nd harmonic wave frequency and is 2nd order in i.
)(),()( // mm
mPm EkJ
B
B
R
n
B
B
r
mk //
TORIC works in combination with FP models (FPPMOD, SSFPQL, CQL3D).
Refs: M. Brambilla, PPCF 41, 1, (1999) & M. Brambilla and T. Krucken, NF 28, 1813 (1988); D. G. Swanson, Phys. Fluids 24, 2035 (1981); P. T. Colestock and R. J. Kashuba, NF 23 763 (1983); J. C. Wright et al,
PoP 11, 2473 (2004)
TRANSP user meeting, JET, 11/01/2008
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TORIC namelist in TRANSP
NICRF=8 ! ICRF model switch (1=new SPRUCE; 5=old SPRUCE, 8=TORIC)...NMDTORIC=31 ! N of poloidal modes: Npol = 2n-1, Npol is calculated for given nRFARTR=5.0 ! distance from antenna to Faraday shield, cmANTLCTR=1.6 ! effective antenna propagation constantNFLRTR=1 ! ion FLR contributions, =1 included, =0 ignored! NFLRETR=1 ! electron FLR contribution, was commented in RB namelist! FLRFACTR=1.0 ! was commented in RB namelistNBPOLTR=1 ! poloidal magn. field, =1 included, =0 ignoredNQTORTR=1 ! toroidal broadenning of plasma dispersionNCOLLTR=0 ! collisional contribution ENHCOLTR=1.0 ! electron collision enhancement factor! ALFVNTR(20) ad hoc collisional broadenning of Alfven and ion-ion resonanceALFVNTR(1)=0.0 ! =1 included, =0 ignoredALFVNTR(2)=0.1 ! enhancement factorALFVNTR(3)=3.0 ! value of abs((n//^2-S)/R) below which damping is addedALFVNTR(4)=5.0 ! value of abs(w/(k//*v_te)) below which damping is calculated
! needed to maintain reasonable values of RF current
Suggested by Robert Budny, the convergency of simulations with this namelist for JET shot has been examined by MIT TORIC experts
TORIC documentation: http://www.jet.efda.org/expert/transp/Toric/Manual/frame.htm
Parameter variations for 66316 (H minority): RFARTR = 2 - 5, ANTLCTR = 1-1.6, ALFVNTR(1) = 0 - 1, ALFVNTR(3) = 3 - 10 no effect on ICRH deposition
TRANSP user meeting, JET, 11/01/2008
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Post-processing:The ICRH power deposition is transferred from TORIC to TRANSP by default. For more
detailed information at given time steps (resonance positions and heating of different species for each antenna separately, wave fields, etc.) the following lines should be
added to the namelist:
FI_OUTTIM(1) = T1 ! T1 [s] is the time for first outputFI_OUTTIM(2) = T2 ! T2 [s] is the time for second output etc. TMAX=9
Detailed results obtained with TORIC are saved in Imp.tgz file.Steps to extract the TORIC data:tar –xz –f Imp.tgz (extracts the files shot#runID_FI_TAR.GZ1 (2,3,etc.) & shot#runID_ICRF_TAR.GZ1 (2,3,etc.)) fi_gzn_unpack
(creates directories shot#runID_fi & shot#runID_icrf. The shot#runID_icrf directory contains the files shot#runID_A#_n-1Ntor_toric5.msgs (fppdata, etc.), input equilibrium and plasma profiles. The routines gfpprf and xfpprf can be used to look at stored results)
TRANSP user meeting, JET, 11/01/2008
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Toric 4 / 5.2 Comparisons
• Toric 4.0 has been available for use with TRANSP for some years• The latest Toric 5.2 code was obtained from Garching, and
substituted for version 4 at the end of 2007. Regression testing uncovered a couple of bugs in the new code
• The current drive normalisation differs by 25% between Torics 4 & 5.2 ; it is still unclear which version is correct.
• These differences raise doubts about the effectiveness of any regression testing of the latest version of the code, prior to its release ( see also http://www.jet.efda.org/expert/transp/Toric/index.htm).
• If the code is to play a significant role in analysis of the new ITER antenna at JET, then in house support by local ICRH experts will be required.
TRANSP user meeting, JET, 11/01/2008
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JET scenarios selected for benchmarking
1. H minority heating (66316): BT = 2.6 T, Ipl
= 2.6 MA, nl 2e19 m-3, Te0 4.8 keV
2. He3 minority heating in RS ITB plasma (69407): BT = 3.45 T, Ipl = 2.5 MA, nl < 2.6e19 m-3, Te0 6.5 keV
3. Fundamental D heating (68731): BT = 3.3 T, Ipl = 2 MA, nl 2.5e19 m-3
4. Mode Conversion, He3 minority, ITB (62077): BT = 3.25 T, Ipl = 2.6 MA, nl < 3e19 m-3
66316
69407
68731
62077
ICRH
NBI
ICRH
NBILHCD
NBI
LHCDLHCD
ICRH
ICRH
NBI
TRANSP user meeting, JET, 11/01/2008
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Benchmarking of old (TORIC/TRANSP) and new (TORIC/TRANSP) versions for H minority heating
- Total electron and ion heating power in perfect agreement;
- Strong disagreement for ICRH electron heating profile;
- It comes from disagreement from power absorbed by minorities
Pe at 6 s
Pe at 7.4 s
Pi at 6 s
Pi at 7.4 s
ICRH electron and ion power depositions
Wave power deposition on
minority
Power from minority to
electrons
TRANSP user meeting, JET, 11/01/2008
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Problem with resonance locations (ex. for 66316)Wave frequency of A2/A3/A4 = 46.16/46.7/ 46.52 Mhz
From *****_toric5.msgs filesMain D:A2: Fundam. resonance at X = -168.291 cm - outside the plasma on the HFS Harmonic resonance at X = -40.572 cm tangent to the surface r/a = 0.52 on the HFSBeam D:A2: Fundam. resonance at X = -168.291 cm - outside the plasma on the HFS Harmonic resonance at X = -40.572 cm tangent to the surface r/a = 0.52 on the HFSC impurity:A2: Fundam. resonance at X = -168.291 cm - outside the plasma on the HFS Harmonic resonance at X = -40.572 cm tangent to the surface r/a = 0.52 on the HFS
… similar for A3 and A4H minority:A2: Fundam. resonance at X = -40.572 cm tangent to the surface r/a = 0.520 on the HFS Harmonic resonance at X = 224.605 cm - outside the plasma on the LFSA3: Fundam. resonance at X = -43.822 cm tangent to the surface r/a = 0.553 on the HFS Harmonic resonance at X = 218.536 cm - outside the plasma on the LFSA4: Fundam. resonance at X = -42.743 cm tangent to the surface r/a = 0.542 on the HFS Harmonic resonance at X = 220.547 cm - outside the plasma on the LFS
From *****tr.log file (simple estimation w/o Doppler shift):Antenna # 2: D harmonic 2 at R= 333.7 cm, D_MCfi harmonic 2 at R= 333.7 cm, C12_6 harmonic 2 at R= 333.7 cm, H_mino harmonic 1 at R= 333.7 cm.
Antenna # 3: D harmonic 2 at R= 336.6 cm, D_MCfi harmonic 2 at R= 336.6 cm, C12_6 harmonic 2 at R= 336.6 cm, H_mino harmonic 1 at R= 336.6 cm.
Antenna # 4: D harmonic 2 at R= 335.6 cm, D_MCfi harmonic 2 at R= 335.6 cm, C12_6 harmonic 2 at R= 335.6 cm, H_mino harmonic 1 at R= 335.6 cm.
TRANSP user meeting, JET, 11/01/2008
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Benchmarking of old (TORIC/TRANSP) and new (TORIC/TRANSP) versions for He3 minority heating
TotalDirect electron heating
Direct ion heating
Minority heating
Electron heating
profile at 7 s
Ion heating profile at 7 s
- disagreement for total electron, ion and minority heating power as well as in Pe & Pi deposition profiles;
- discrepancy comes from different power absorbed on minority (like for 66316)
However, there is perfect agreement for 68731 (fund. D heating) where minorities
are not involved
Fund. He3 resonance at r/a=0.15 HFS (msgs)
TRANSP user meeting, JET, 11/01/2008
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Effect of re-normalisation of quasi-linear operator (QLO) on power deposition for minority heating
- ICRF wave codes specify both the damping power density on minority fast ions, and the 2D wave field (E+, polarization, k, kll). In theory, the QLO coefficients are fully determined by the
wave field alone.
- Because of differences in the representation of fast ion distribution between the FP model and wave code, the damping power implied by QLO from the wave field alone may not match the damping power expected by the wave code, and the integrated profile will not match the power-at-the-antenna that was specified to wave
code.
- FPPMOD operator re-normalises the original QL operator zone by zone while keeping the total power constant. Low and upper limits of normalisation constant are fixed in TRANSP. When the normalisation constant exceeds one of these limits it will be restricted by this limit, but then the power should be re-distributed along the radius to have the same total power. This creates the distortion of deposition profiles and shift of the maximum absorbed power with respect to real resonance location.
old TORIC/TRANSP
new TORIC/TRANSP
PWAVEMIN (red) – power damped on minority calculated by TORIC; PQSLMIN (blue) – power
obtained with non-normalised QLO in TRANSP; PQLNORM – power damped on minority after the
normalisation of QLO (scaled by
PWAVEMIN/PQSLMIN)
TRANSP user meeting, JET, 11/01/2008
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Update of FPPMOD routine
Warning: user should check the normalisation of QLO (gfpprf xfpprf (last plot) or multigraph RFHMIN_H (or _HE)) and compare original profile of TORIC wave power deposited on minority, non-normalised QL operator profile and normalised QL operator by TRANSP FP module fppmod. The profiles FWAVMIN and FQLNORM should coincide.
Immediate action: Doug added the minimum and maximum renormalization factors "min_qlnorm" and "max_qlnorm" in the FPPMOD namelist and raised the upper limit on the QL re-normalisation from 3 to 20.
To change these in the FPPMOD namelist when running xfpprf from data saved with FI_OUTTIM(...): in addition to the values themselves one have to set
mstate=1to prevent the namelist changes from being overwritten by the "state file" which is used when
xfpprf is run in this mode.
Long-term action: include the limits for the normalisation constants in the TRANSP namelist
TRANSP user meeting, JET, 11/01/2008
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Benchmarking between TORIC and SPRUCE for H minority heating
This benchmarking has been done with the same TRANSP version switching from SPRUCE to TORIC
Direct electron heating
Power to fast ions
Direct ion heating
Total power
Power to minority
Evolution of total powers Power deposition at 6.6 s
Total absorbed
powerDirect electron
heating
Direct ion heating
Minority heating
Electron heating from minority
Ion heating from minority
TRANSP user meeting, JET, 11/01/2008
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Different power deposition in all channels different
electron and ion heating power profiles
TORIC
TORIC
SPRUCE
SPRUCE
Electron heating power profile
Ion heating power profile
QLO
TORIC
6.6 s
SPRUCE
TRANSP user meeting, JET, 11/01/2008
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Benchmarking between TORIC and SPRUCE for He3 minority heating (I)
Total
Direct electron heating
Direct ion heating
Minority heating
Evolution of total powers Power deposition at 7.5 s
Total absorbed
power
Direct electron heating
Direct ion heating
Minority heating
Electron heating from minority
Ion heating from minority
TRANSP user meeting, JET, 11/01/2008
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Electron heating power profile
Benchmarking between TORIC and SPRUCE for He3 minority heating (II)
Ion heating power profile
TORIC
TORIC
SPRUCE
SPRUCE
TRANSP user meeting, JET, 11/01/2008
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Fundamental D heating with TORIC (I)
Evolution of powers
Total
Direct ion heating
Direct electron heating
Fast ion
Power deposition at 7.5 s
Total
Direct electron
Fast ion
Direct ion
Minority
Minority electrons
Minority ions
TRANSP user meeting, JET, 11/01/2008
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Fundamental D heating with TORIC (II)
TRANSP user meeting, JET, 11/01/2008
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Mode Conversion case (62077) can be compared with TOMCAT [P. Mantica et al, PRL March 2006]
Direct electron heating (FW)
Minority heating
Minority to electrons
Minority to ions
Fast ion & direct thermal ion heating
Smaller time step should be used
TORIC does not show mode conversion number of poloidal modes should be strongly increased
TRANSP user meeting, JET, 11/01/2008
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Effect of the number of poloidal mode: deposition profiles at minimum (red & pink) and maximum (blue & green) modulation amplitude obtained with NMDTORIC=31
(red & blue) and NMDTORIC=63 (pink & green)
Total absorbed power
Direct electron heating
Fast ion heating (small)
Direct ion heating
Minority heating
Minority to electrons
Minority to ions
- The results are weakly affected by the choice of poloidal modes;
- Modulation affects direct electron and minority heating, but not the power given to electrons and ions from minority. Finally, only central electron heating is modulated
TRANSP user meeting, JET, 11/01/2008
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Electron and ion heating profiles at minimum (red & pink) and maximum (blue & green) modulation amplitude obtained with NMDTORIC=31 (red & blue) and
NMDTORIC=63 (pink & green)
TRANSP user meeting, JET, 11/01/2008
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Summary of simulation results and discussion
• Effect of inaccurate re-normalisation of QLO has been found and re-normalisation has been improved, but users should always check the re-normalisation
• There is still a problem with resonance locations in *****.msgs file
• These problems were not seen in Cmod test case JET discharges contributed to regression test
• Large difference between TORIC and SPRUCE for minority heating case: negligible direct ion heating with TORIC (heating on second harmonic is not taken into account?), different heating profiles. Large and very localised central electron heating is not clear in ITB discharge. Benchmarking of SPRUCE and TORIC with the same number of modes is suggested.
• Fundamental heating – edge absorption? More shots with proper antenna frequencies should be tested. The study of this scenario by Ernesto shows that mainly beam ions are heated by ICRH.
• Mode Conversion – qualitatively in agreement with TOMCAT & PION, but wrong resonance location in *****.msgs file and no MC. Suggestion of ICRH experts: much larger number of poloidal modes (at least 200) should be used.
TRANSP user meeting, JET, 11/01/2008
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Conclusion of TRANSP and ICRH experts:
TORIC does not provide an ‘off the shelf’ solution to analysing JET RF pulses. At present we cannot explain or solve the problems found in TORIC simulations of JET plasmas, or the observed differences between the ICRH codes
In the opinion of those present, development of ICRH modelling for JET will require the full time attention of an ICRH expert.
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