Conceptual Design for NCSX Auxiliary Systems

1. Conceptual Design for NCSX Auxiliary Systems Heating, Fueling,Wall Conditioning and Vacuum Systems H.W. Kugel Slide 1

2. NCSX NBI Heating Requirements • Requirement BaselineUpgradeLong Term • H0 Power 3 MW 6 MW 6 MW • Pulse Length 300 msec 300 msec 1.2 sec • Voltage 50 kV 50 kV 50 kV • Orientation 1-Co,1-Cntr 2-Co,2-Cntr TBD (or 3-Co,1 Cntr) • Focusing 3 MW to 6 MW to 6 MW to Plasma Plasma Plasma H.W. Kugel Slide 2

3. Neutral Beam System Design Description: The Design Will Provide the Required Performance • NBI Alignment Provides for: • Balanced co- and cntr- injection for control of NB driven currents and rotation. • NBI Ports Located for: • Maximizing absorption of injected power on the desired plasma region. • Minimizing effects on injected species. • Minimizing injected power absorption on ports on opposite wall. H.W. Kugel Slide 3

4. Neutral Beam injection Pulse Length Plan • PBX-M NBI systems pulse lengths were typically ~300 ms. • The NB power handling surfaces were engineered to operate to 500 msec pulse lengths at the full power, peak power density of 3 kW/cm2 • ORNL found that beyond 400 ms, the Ion source Idecel increased too much. • A control technique was developed. • ORNL operated one ion source with H0 to 500 msec at ~1.5 MW • With this, PBX-M demonstrated 500 msec at reduced power (4MW total ) • Each NBI demonstrated to operate with D0 at ~40 KV, 1 MW, to 500 msec. Operation to higher powers at 500 msec is feasible for both H0 and D0 • MAST using similar ORNL NBI plans to upgrade to 1.5-3 sec pulses. • NCSX will adopt this technology for long pulse NBI H.W. Kugel Slide 4

5. Design Description: Test Cell Can Accommodate the Required Beam Arrangement H.W. Kugel Slide 5

6. Design Description: Beamlines Connect to High Conductance Auxiliary Systems Duct for Minimal Reionization Losses • Lower Divertor Viewport Torus • NB Port (one on each side of Auxiliary Systems Duct) • Vessel Entrance Port • To Torus Pumps H.W. Kugel Slide 6

7. Design Description: Beamlines Aligned for Co- and Cntr- for Beam Balance Studies and Control of Beam Driven Currents • Inner Circle Encloses ~47% of Injected Power. • Outer Circle Enclosing ~96% of the Injected Power from NB-S (IS#1) (HWHM =1.5°) Superimposed on the Oblate Target Plasma. • The Vessel Far Walls Will Have NB Armor H.W. Kugel Slide 7

8. NBI Design Definition Includes Scope, Schedule, Costs, Risks, and Measures for Risk Reduction • Scope Prior to First Plasma: • Repair and refurbish existing Beamline hardware • Repair and refurbish existing Power Systems • Install Beamlines on NCSX • Make all cabling and other connections • Achieve Beamline operating vacuum • Design strategy: will apply methodologies and procedures developed during previous 17 year operating history. H.W. Kugel Slide 8

9. NCSX Fueling Requirements, Design Description and Performance • 2 to 4 Injectors for 200-400 torr-liter/sec of H2, D2 or He. • Flexibility for easy changing of gas plenum volumes, or adding additional injectors at selected vessel locations. • Will re-use parts from the existing PBX-M Gas Fueling system. • Controls will be upgraded with a modern PLC using the proven NSTX design. • Procurement and fabrication records from the high performance NSTX design will help to implement the design. • Will accommodate Pellet Injector as future upgrade. H.W. Kugel Slide 9

10. NCSX Wall Conditioning Requirements, Design Description and Performance • Glow Discharge Cleaning (GDC) during maintenance, Bakeout, and between discharges as required. • One fixed wall anode and one biased dual pre-ionization filament in each sector. • H2, D2 or He pressures of ~2-4 mTorr, positive bias of ~500 v applied between the anode (+) and the vessel (-). • Pre-ionization electrons facilitate breakdown of ioniztion at the desired operating pressure and voltage to simplify controls. • Design will capitalize on recent NSTX experience with designing, procuring, and installing a similar system. H.W. Kugel Slide 10

11. NCSX Vacuum Requirements, Design Description and Performance • Produce base pressures of at least 2x10-8 torr. • Will re-use parts from the existing PBX-M Torus Vacuum Pumping System. • Four PBX-M 1500 l/s turbo-molecular pumps, configured for total pumping speed of at least 2600 l/s (PDX). • Four Welch Model 1398 belt driven backing pumps. • One Kinney 500 belt driven roughing pump. • Gate valves, flanges, instrumentation. • New Residual Gas Analyzer. • Controls will be upgraded with a modern PLC using the proven NSTX design. H.W. Kugel Slide 11

12. Design Description: High Conductance Auxiliary System Duct Provides for Torus Pumping Duct, Neutral Bean Duct, Diagnostic Viewports, and Vessel Entrance Port Insulator break / bellows assembly • Assembled Auxiliary Systems Duct • - NBI Duct • - Pump Duct (~1.5-2 PDX) Conical reducer 36” OD pipe Adapter flange 10” gate valve 1500 l/s TMP H.W. Kugel Slide 12

13. WBS 2: Auxiliary Systems Costs • WBS 21 Gas Fueling: 144.7 K* • WBS 22 Torus Vacuum Pumping: 306.6K* • WBS 23 GDC Wall Conditioning: 104.8K* • WBS 25 Neutral Beam Heating: 1741.5 K* * with 18% Contingency H.W. Kugel Slide 13

14. Conclusions • The Neutral Beam design adopts the high performance NBI system of the PDX, PBX, and PBX-M projects - provided automated, reliable, economical operation during 17 year operating history. • The Fueling, Wall Conditioning, and Vacuum system designs make use of PBX-M parts and adopt proven NSTX engineering designs for similar systems. • The designs minimize technical, cost, and schedule risks by re-using existing equip,adopting NSTX engineering, and testing off-line. H.W. Kugel Slide 14