# Presentation: 708762

## NSTX Facility/Diagnostic Status

***Columbia U***
***Comp-X***
***General Atomics***
***INEL***
***Johns Hopkins U***
***LANL***
***LLNL***
***Lodestar***
***MIT***
***Nova Photonics***
***NYU***
***ORNL***
***PPPL***
***PSI***
***SNL***
***UC Davis***
***UC Irvine***
***UCLA***
***UCSD***
***U Maryland***
***U New Mexico***
***U Rochester***
***U Washington***
***U Wisconsin***
***Culham Sci Ctr***
***Hiroshima U***
***HIST***
***Kyushu Tokai U***
***Niigata U***
***Tsukuba U***
***U Tokyo***
***JAERI***
***Ioffe Inst***
***TRINITI***
***KBSI***
***KAIST***
***ENEA, Frascati***
***CEA, Cadarache***
***IPP, J******ü******lich***
***IPP, Garching***
***U Quebec***

**NSTX PAC Meeting**
- Sept. 9 -10, 2004

- Masayuki Ono

## NSTX Facility/Diagnostic Status Outline

- Facility and Diagnostic Status
- TF Joint Support Structure Issues and Resolution
- Draft FY05-07 Facility and Diagnostic Upgrade Plan
- Summary

## NSTX successfully completed the run on Aug. 5 

- Programmatic goal: 20 weeks

- NSTX successfully completed the run on Aug. 5

- Completed 21.1weeks*
- With 2460 plasmas
- Supported 43 XPs &  9 XMPs
- Exciting FY 04 Research Activities

- * Run details are available on the NSTX Web.

## New Facility/Diagnostic Capabilities in FY04

_**Facility Improvements:**_
- Two (out of six) RWM Coils
- Control system upgrade for higher elongation (All areas)
- Reduced latency (<1 msec)
- rtEFIT2 external EF/RWM control coils (Macro)
- CHI capacitor bank – (Macro)
- Li pellet injector  (Interface)
- Supersonic gas injector –  (Interface)
- PF4 commissioning –  (Macro)
- Improved boronization schemes (Interface)

_**Diagnostic Improvements:**_
- MSE – up to 8 channels (All areas)
- Fast tangential x-ray camera
- Divertor Mirnov arrays, internal RWM sensors (Macro)
- 51 channel CHERS (Transport, Macro)
- Scanning NPA (Transport, Macro, Wave/Part)
- USXR, FIRETIP upgrades (Macro, Transport)
- Edge rotation diagnostic to measure edge Ti, v, Er (Transport, Wave/Part)
- Upgraded correlation reflectometry – long  turbulence (Transport)
- Fast cameras (Transport, Interface)
- RF Probe (Wave/Part)

## Two RWM coils successfully installed during the run and energized using a rectifier power supply.  

- Two RWM coils successfully installed during the run and energized using a rectifier power supply.

- The full Six-element RWM coil system powered with the SPA (Switching Power Amplifier) supply is scheduled to be available for the FY 05 run.

- Yielded some exciting results:
- • Locked-modes were shown to be stabilized in a factor of 2 lower density regime.
- • Enabled start of exciting RWM investigation (Talk by S. Sabbagh)
- • Used to control the plasma rotation velocity

## Capacitor Bank for Transient-CHI Start-Up Commissioned

- •	Operated reliably up to 1 kV
- •	Produced reliable breakdown with lower gas pressure
- •	Generated Ip ~ 140 kA with Iinj ~ 4 kA in a few milliseconds
- •	Measured peaked profiles Te0 ~ 16 eV

- Absorber

- Injector

- Future improvement possibilities:
- • Te increased with reduced pressure - can we reduce it further by:
- 	- Gas + ECH injection into injector?
- 	- Higher voltage > 1 kV?
- • Plasma stability/controllability
- 	- Energize absorber coils
- 	- Need to develop control algorithms

## Injected Lithium Pellets into NSTX Discharges

- •	Capability for injecting solid pellets (<1 – 5 mg) & powder (micro-pellets)
- •	10 – 200 m/s radial injection
- •	1 – 8 pellets per discharge
- •	400 pellet capacity
- • Need to optimize performance

- Lithium “vapor ball” surrounding pellet as it approaches the center-stack

- Lithium vapor spreading along the center-stack

- In-board gas injector

- Lithium Pellet moving through plasma after entering at 296ms

## Facility Upgrade Highlights Continue

## MSE and Fast X-ray Camera Commissioned

- MSE Multistage Lyot Filter

-  Images of the soft x-ray emission along tangential sightlines recorded by an ultra-fast camera with time resolution down to ~ 2 μs

## Hiroshima Divertor visible camera shows clear differences between Type I (large) and Type V (small) ELMs

**Hiroshima Divertor visible camera shows clear differences between Type I (large) and Type V (small) ELMs**

- Periodic Type V ELMs interrupted by a Type I ELM (approximate camera field of view in LHS yellow box)

**Nishino (U. Hiroshima), Roquemore, Maingi (ORNL)**

- Inner separatrix
- Outer strike point

## TF Joint Behavior Has Been Monitored and Studied Throughout the Run

- Hub plate

- Flag with box

- •	In January, an integrated system test was conducted to qualify the machine.
- •	The measured resistance of each joint was well below the <700nΩ design goal at 4.5kG and the temperature rise was in accord with expectations.
- •	However, a closer examination of the data and trends over time raised some concerns.

## New Data and Analysis Has Identified Some Concerns About the TF Joints

- • 	Small upward drift in the joint resistances observed over ~4 months of operation.
- 	- All remained well below 700nΩ.
- •	Temperature and strain gauge measurement also revealed changes over time.
- • 	Subsequent measurements showed larger than expected TF-flag displacements.
- • 	New simulations and bench tests indicate the measurements are consistent with larger than expected joint “lift-off”.

- TF Joint Resistance in nΩ
- [Start-of-Flat-Top. Test Shots]

- To assure safe device operation, we instituted TF operational limit of 3kG with Rmax<150 nΩ in July.

- 150 nΩ

## Working to Resolve These Concerns

- Working to Resolve These Concerns

- •	Progress in understanding the TF joint behavior:
- -	Movement of flag joints confirmed and quantified through a number of measurements
- -	Modeling suggests that the cause of the flag movements is softer than expected epoxy fill in the flag box
- -	Bench tests of the removed flags did confirm this shortcoming
- -	Alternate fill material being tested to give adequate strength for the next run

- Project decision: Replace epoxy in all the flag joints

- • 	Outage schedule developed:
- 	- Complete the in-vessel work and pump down in mid-Nov. 04
- 	- Complete the magnet assembly in Dec. 04
- 	- ISTP of magnets in Jan. 05 and plasma operation in Feb. 05 (similar to this year)
- •  	Present Status:  Outage activities progressing on schedule
- 	- Central TF-OH bundle is moving to the work stand
- 	- Lower flag box disassembly completed

## Adjustments of Facility/Diagnostic Plan

- Taking advantage of the center-stack removal:
- Implement PF 1A coil upgrade one year ahead of schedule for better shaping capability — simultaneous high  and  — for advanced ST operations

**114465**

- PF1A

-  Repair/improve plasma current Rogowski coils

## MHD Mode Stabilization

- Six-Element RWM External Coils with a SPA Supply (Columbia)

- Opportunity Areas are Shaping and RWM Controls.

- MHD Diagnostics
- &
- Analysis Tools

- Plasma
- Operations

- FY 04

- FY 05

- FY 06

- Wall-mode sensors (Columbia)

- Ultra-soft x-ray arrays (JHU)

- Fast MHD sensors

- Improved magnetics

- Fast X-ray cameras (Frascati, JHU, PSI)

- Res. Field & RWM Control System

- Real Time EFIT (GA)

- SPA Procurement

- Coil Fab./Instal

- Error Field Reduction /
- Plasma Rotation Control (Columbia)

- Shape Control
- Higher Elongation

- PF 1A Modification

- EFIT with Plasma Rotation (Columbia/GA)

-  Base

-  Available

**DRAFT**

- PF1AStatus: FDR in Oct.
- Winding in Nov
- Installation in Dec.

- RWM System Status:
- SPA to arrive in Oct.
- Coils installed in Nov.
- System ISTP in Jan. 04

## Confinement and Transport

- Exciting Opportunities For Advanced Fluctuation Diagnostics

-   Prototype High k Microwave Scattering( UCD)

- Tor. CHERS (51 ch)

- Edge Pol CHERS

- Profile Diagnostics

- Energetic Particles

- Fluctuation Diagnostics

- Fast Loss Ion Probe

- FIReTIP 4 ch (UCD)

- FIReTIP 6 ch  (UCD)

- MPTS 30 ch

- MPTS Third laser

- Edge Rotation Spect.

- Low k Reflectometer (UCLA)

- Reciprocating probe (UCSD)

- Gas-puff Imaging(LANL, PSI)

- ERS Upgrade

- Neutron Collimator

- MSE / CIF
- 12-14 ch (Nova)

- MSE/CIF
- 4- 8 ch (Nova)

- MSE / LIF
- (Nova)

- MPTS 20 ch, two laser

-  Base

-  Available

- Low k Imaging Reflectometer

**DRAFT**

## Non-Inductive CD Systems

- Enhancement Opportunity areas are EBW and Solenoid-free Start-up

- CHI
- (IT = 0.5 MA)

- HHFW
- (6MW)

- EBW -E / -CD

- Dynamo-head
- For Helicity-Transport (UCSD)

- O-X-B EBW Emission Expts

- HHFW Feed Improvement

- Transient CHI
- Capacitor Bank
- (U. Washington)

- System Design  / Costing

- DIII-D/MAST Collaboration Expts.

- PF Coil
- Start-up

- PF 4 Energization

- Prelim Design
- Begin Site Prep

- Complete Site Prep

- EBW System
- Construction

-  Incremental

-  Base

-  Available

**- **Decision Point

**DRAFT**

- Procure EBW Tubes

- High Power EBW System:
- • Requires significant capital investment
- • Working to minimize the cost
- • To explore collaboration opportunities

- Prelim Design

## Boundary Physics

- Exciting Enhancement Opportunity in Core Fueling and Boundary Physics

- Fueling

- Wall Conditioning

- Supersonic
- Gas injector

- Power / Particle Control

**Divertor Cryopanel / **
**Liquid Li Module**

- Li Pellet Injector

- (Gas/plasma Boronization,
- Between-shot GDC)

- (In-board gas
- injectors

- Pellet injector in "suitcase”
- (ORNL)

- Fast IR Camera
- (ORNL)

- Divertor IR Camera
- (ORNL)

- Lithium Evaporator

- Hot-boronization

- Between-shots boronization

- CT injector
- Lab. Test

- Divertor Probe

- Vert. Divertor Bolometer

- Horiz. Divertor Bolometer
- Div. Spectrometer

-  Incremental

-  Base

-  Available

**- **Decision Point

**DRAFT  **

- Improved He-GDC

## NSTX Facility/Diagnostic Status Summary

- Restart in Feb. 2005 with significantly improved facility and diagnostic capabilities for up to 21 run weeks

- Productive FY 04 run completed on Aug. 5, 2004
- Successfully operated for 21.1 weeks with 2460 plasmas
- Met the Joule milestone of 18 weeks and programmatic goal of 20 weeks.
- Many exciting new capabilities were implemented
- RWM coil energization, CHI capacitor bank, rapid boronization, PF4...
- MSE, Fast tangential X-ray cameras, Divertor cameras, Improved GPI...
- TF joint monitoring showed larger than expected movement
- TF limit of 3 kG was imposed during the last month of operation
- The cause of movement traced to softer than expected epoxy fill
- TF bundle has been removed and improved epoxy fill will be implemented
- Some upgrade adjustments made for the outage
- Accelerate PF 1A upgrade
- Complete RWM coils with SPA, high-k scattering, 10 extra MPTS channels
- Delay lithium evaporator and poloidal CHERS detector by one year