# Presentation: 140157

## Research Interests for 2006 in Transport & Turbulence

**Turbulence measurements with high-k ********-wave scattering**
***Milestone R(06-1)****: Measure short wavelength turbulence in the plasma core in a range of plasma conditions. (September 2006)*
- Study of RS discharges with & without eITBs
- L- and H- mode shots
- Perturbative studies of electron transport
- Effects on transport of reducing recycling by lithium coating
- Scaling of confinement, particularly  & B, A dependence
- ITPA: CDB-2 (), CDB-6 (A), CDB-8 (*), CDB-9 (low ne, Te≈Ti)
- Also scaling studies for NSTX-U

## Progress in High-k Scattering Experiments

- Commission and evaluate diagnostic in XMP-44
- Lost some time early in run to technical problems
- ~35 dedicated shots on 3/20-21 plus periods of controlled access during other experiments
- Still some issues surrounding adequacy of beam alignment
- Measuring changes in signals related to phenomena known to cause or change density fluctuations
- Data presented this week at HTPD Conference
- Now need to develop dedicated XP in optimal conditions
- Low-density, reverse-shear shots which develop eITBs
- H-mode transitions
- Producing quantitative fluctuation data will require extensive calibration and analysis post-run

## Results from High-k Scattering 

- Fluctuations decrease at H-mode
- Outboard launch ρ ≈ 0.95

- Fluctuations from CAE/GAE
- Well correlated with Mirnov data
- Inboard launch ρ ≈ 0.04
- kρe = 0.3-0.15

## Injection and Penetration of Li-doped TESPEL

- XMP-47 (Stutman *et al.*) completed on 3/24 (7 shots) during visit of collaborator N. Tamura (NIFS)
- Inject small (few hundred μm) shells of deuterated polystyrene filled with LiH tracer (few x1018 LiH) using LPI
- Observe penetration with Li telescope, Li-filtered optical detectors, USXR
- TESPEL penetrated ~5cm in L-mode with NBI
- Density perturbation few %
- TESPEL did not penetrate scrape off in 6MW H-mode
- TESPEL produced small density near edge inside LCFS in 4MW H-mode
- TESPEL penetrated deeply insode and demolished a 2MW H-mode
- Utilized remaining TESPELs in XP-612 on 5/3

## Completed First Phase of RS Experiment 

**XP-610** (Levinton, Yuh) run on 3/27–28 (33 shots, 10.6hr)
- FCPC (2hr), “acq” errors (8), diagnostics (1hr), MG trip (30min)
- Ip = 0.8 – 1.0 MA, BT = 0.45 T, PNBI = 2 MW

- Adjusted growth phase, NB timing to vary q(r,t)
- some success but performance quite variable
- Reproduced Te(0) = 2.0 keV with apparent RS
- Data now being analyzed
- Phase 2 (BT = 0.5, 0.55 T) andPhase 3 (RS H-mode) remain to be explored
- Estimate 2 days of runtime

## Investigated Perturbed Electron Transport in H-mode

**XP-612** (Stutman *et al*.) run on 5/3 (20 shots, 6.9hr)
- FCPC 3 shots, PCS 5 shots lost
- Inject small Li pellet or Li-doped TESPEL into 1.0MA, 0.45T, H-mode heated with 2 – 6 MW NBI
- L-mode not investigated yet
- Followed evolution of Te perturbation with USXR, OSXR, Li telescope
- LPI worked well
- Observed expected increase in speed of propagation with heating power, *but*
- Perturbation was smaller than in prior years
- On one shot pellet triggered transition to lasting improved confinement
- Desirable to reproduce some shots with larger perturbations from C pellets
- Requested LPI team to load suitable pellets for next period of operation
- Estimate 2 hours operation to document shots
- L-mode phase of experiment needs additional 4 hours *if previous (2005) discharges are reproducible*

## Experiments Planned or Under Consideration for Remaining 2006 Runtime 

- Z-scaling of impurity transport in NB heated H-mode discharges (L.F. Delgado-Aparicio, JHU - thesis work)
- OSXR array now operational
- Use C pellets and/or CD4 puffing to introduce C and follow evolution
- XP to be reviewed by ET Group next week
- BT and  scaling of confinement: XP-532 (Kaye)
- Provide NSTX contributions to ITPA tasks CDB-2 (), CDB-8 (*)
- Approved in 2005 but thwarted by TF restriction
- Needs 0.5, preferably 0.55 T toroidal field: now ready
- Dedicated XP for High-k Scattering (Smith *et al.* - thesis work)
- XP to be developed: use existing scenarios as much as possible
- Scaling study for possible upgrades to NSTX (Bell *et al.*)
- NSTX-U now a higher priority?
- Scans constrained by dependences in systems code studies
- XP to be developed: new scenarios will challenge control system