SL-plan for run:1110218
MP655:Characterization of WCM behavior and estimates of transport at the edge
SL: Dominguez
PO: Granetz
The objective of this MP is to study the relationship between the characteristics of the weakly coherent mode (WCM) and the energy and particle transport at the edge of the plasma as well as the WCM dependence on edge temperature and pressure gradients.
The use of various fluctuation diagnostics, mainly: O-mode reflectometry, GPI, PCI, fast magnetics and FRCECE, will be used to study the different characteristics of the WCM.
The experiment will focus on reproducing long sustained I-modes at 4 different (nl04,Ip) values during which the ICRF power will be stepped in order to modify the temperature and pressure gradients close to the LCFS.
The solicited diagnostic set is:
O-mode fixed reflectometry
Core and Edge Thomson
PCI (no masking)
Fast magnetics
GPI
FRCECE
X-mode SOL reflectometer
H(alpha) GPI camera set for profile measurements. To be used for particle transport analysis.
CXRS
HIREX Sr
HIREX Jr
Cryopump (in standby)
If possible, it is asked for fluctuation diagnostics to connect the global timing signal for post-run analysis.
Run plan for 1110218xxx:
In order to optimize GPI fluctuation diagnostic, He puffing will be used. This is also compatible with the D(alpha) GPI camera.
Yijun has informed me of the need to modify the position of the SOL-reflectometry horn before the 1/2 day run begins.
This will be a 1/2 day (second half) so we will focus on parts 1) 2) and 3a) in the MP run plan:
1) 3 shots:
Reproduce shot 1110215023 but with faster density and current ramps to nl04=0.9E20m^-2 and Ip=1.2MA and ICRF power scan as described in the MP:
- At ~0.5s ramp ICRF:0-3MW during 100ms
- Ramp the PICRF from 3-5MW from 0.6-1.6s and determine the P(I-H)
2) 3 shots:
Using the recipe developed in (1), scan the ICRF power in 100ms steps from P(L-I) to right below the P(I-H)
and then step back down to below the P(L-I) (this step assumes some level of hysteresis). Refer to figure 1 attached.
Before 3a), we will try to repeat a good I-mode shot with a change of gas puffing to D2 in order to get a comparison for MP#656 (which will be very useful for post-analysis). This will comprise of a cell access before the shot and one after.
3a)Repeat 1) and 2) with nl04=1.1E20m^-2. For this case, ICRF power will be scanned as:
- At ~0.5s ramp ICRF:0-3.5MW during 100ms
- Ramp the PICRF from 3.5-5.5MW from 0.6-1.6s and determine the P(I-H)
Based on recent run days, there's a good chance that disruptions are prevalent. If they appear repeatedly, there is the possibility to jump to the lower current 3b) and 3c) from the MP (1.0MA @ nl04=0.7 and 1.0 E20).
"Effects of RF heat on edge/SOL poloidal velocities"
This is the 2nd half day for this MP; the
other half day took place on 1110127 (in normal field)
We desire normal ECDC preparation.
NINJA with 10 PSI He^4
We are examining the strong changes in the edge/SOL profiles
of the phase velocities of the fluctuations brought
about by the application of ICRF power above a threshold of
~0.6 MW. These changes are
measured by the outboard midplane GPI.
Critical diagnostics:
Midplane GPI
A port scanning probe - to probe when PRF<1 MW
Emissive probe on S^3
The run plan is:
Load (reversed field) shot 1110217014.
Ip=0.8 MA
Bt=5.4 T (-->q95=4.7)
LSN
adjust NL04 of the target plasma to 0.7e20 m-2
adjust outer gap to 2.0 cm
adjust RF waveform to reproduce that of shot 1110127014 which
had D & J activated in a stairstep power ramp from
0 to 2.4 MW, in steps of 0.5, 0.9, 1.3, 1.7, 2.0, 2.4 MW.
The 1st step turns on at 1.05 s and each step lasts 50 ms.
Puff the NINJA so that the puff hits the plasma at 0.98 s
Perform 3 shot density scan:
NL04 = 0.7e20 m-2 (1st good shot)
NL04 = 0.4e20 m-2 (2nd good shot)
NL04 = 0.55e20 m-2 (3rd good shot)
Perform 3 shot q_95 scan in order to vary the mapping from
GPI to the D & J antennas (Bt=5.4 T)
Ip=0.4MA (NL04=0.7e20) (--> q95=9.5)
Ip=1.0MA (NL04=0.7e20) (--> q95=3.8)
Ip=1.2MA (NL04=0.7e20) (--> q95=3.16)
Perform Power scan with USN and J antenna only (steps of 0.2 MW to 1.2 MW)
Perform scan of heating scenario & ICRF resonance location:
Bt=2.7T, Ip=0.4MA (-->q95=4.7) NL04=0.4e20 m-2 (2nd harmonic H minority)
Bt=3.5T, Ip=0.52MA (-->q95=4.7) no resonance in plasma, only 2 RF power steps (to 0.9 MW max)
Bt=4.5T, Ip=0.52MA (-->q95=4.7) resonance at R~0.55 m
Repeat q95 scan with J antenna only
Ip=0.4MA (NL04=0.7e20) (--> q95=9.5)
Ip=1.0MA (NL04=0.7e20) (--> q95=3.8)
Ip=1.2MA (NL04=0.7e20) (--> q95=3.16)
Perform Power scan with USN and D antenna only (steps of 0.2 MW to 1.2 MW)
Total of 14 good shots
