Assess Heating/Current Drive/Fueling systems for candidate burning plasma devices to determine their capabilities with regard to meeting the physics objectives, operating performance and flexibility, and ability to test advanced Heating/Current Drive/Fueling systems under reactor relevant conditions. These capabilities should be achievable while meeting all safety and reliability goals. The necessary R&D to develop the Heating/Current Drive/Fueling systems should be identified and completed in a time frame consistent with construction schedules for the burning plasma device.

ECH heating and current drive

1. Long pulse, high power source development
2. Low loss transmission line development
3. Launcher development

ICRF heating and current drive

1. Antenna spectrum and current drive efficiency
2. High power density and long pulse antenna development

1. Plasma facing materials
2. Actively cooled components

1. Phased antenna array development

1. Diagnostic development
2. Tuning, matching and feedback control systems

1. Plasma wave interactions and reliability improvements

Lower hybrid current drive

1. Antenna spectrum and current drive efficiency
2. Launcher development

1. Plasma facing materials
2. Actively cooled components

1. High power source development

Neutral Beam current drive

1. Long pulse NB development

1. Steady state ion sources
2. Actively cooled components

Plasma fueling and pumping

1. Pellet injector development
2. Inside pellet launch development
3. Advanced pumping systems

1. P1 - Wave-Particle Interactions Physics
2. P2 - Energetic Particles/Alpha-Physics
3. P5 - Boundary Physics
4. E2 - Integrated Scenarios/Ignition Physics/Burn Control
5. T2 - PFC/Heat Removal
6. T4 - Vacuum vessel/Remote handling
7. T6 - Cost

• Key issues and R&D identified.
  What heating and current drive and fueling requirements and systems have been identified for each candidate burning plasma device?
  Are the technology requirements for each heating / current drive / fueling system within the current state-of-the-art?

• Maturity of design (pre-conceptual, conceptual, detailed).
• Expected performance

• Operating margins and flexibility.
  Is there adequate margin in the design? Can the H&CD systems support the full range of the operating space?
• Feasibility of manufacturing. Are there any manufacturing showstoppers?
• Need for further R&D

• Credibility of capital and operating costs.
  Are the estimated costs in line with experience with similar systems?
• Relevance to demo
  What unique heating / current drive / fueling technology development is enabled by a burning plasma experiment?
• Relevance to other fusion experiments and applications
  What unique heating / current drive / fueling applications are enabled by a burning plasma experiment?
• Reliability and off-normal conditions considered.
  Is the H&CD system robust to changing plasma conditions? Can the H&CD system handle off-normal thermal and disruption loads?
• Interfaces identified and addressed.
  Is there adequate port space allocated for the H&CD systems? Is the ICRF antenna-to-wall gap sufficient? Is the plasma-to-antenna gap small enough for efficient coupling? Are the PFC's compatible with the H&CD systems? Is there access for tangential NBI? Is there access for inside pellet fueling? Is there adequate port and divertor space for pumping?

1. Review published results on heating / current drive / fueling system designs for each candidate machine.
2. Discuss heating / current drive / fueling requirements and proposed systems with technical staff working on each candidate device.
3. Identify unique heating / current drive / fueling technology development opportunities that a burning plasma experiment can address.
4. Review results at meeting(s).
5. Prepare written document for Snowmass.

ECH R. Temkin (MIT), R. Callis (GA) M. Makowski (GA), T. Imai (Japan)

ICRF D. Rasmussen (ORNL), D. Swain (ORNL). S. Wukitch (MIT), J. Hosea (PPPL), G. Bosia (ITER)

LH S. Bernabei (PPPL), R. Parker (MIT), G. Tonon or C. Gormezano (Tore Supra)

NB L. Grisham (PPPL), J. Tsai (ORNL)
Fueling and pumping L. Baylor (ORNL), S. Combs (ORNL), T. Jernigan (ORNL), G. Schmidt (PPPL)

The assumption is that each, burning plasma device, team will provide the bulk of information but this is an iterative process especially for current drive, and temperature and density profile control. There is also a strong linkage to the physics requirements and the specific operating scenarios.

For ITER, the ECRH&CD, NBH&CD, LHCD and FWH&CD designs are well developed and documented. Outside, inside, and vertical pellet injection, capabilities are included in the design. The divertor pumping plans for ITER are well developed and documented.

For FIRE, the operational scenario (and nominal B field) is still being developed but the basic requirements are mostly known. The FWH&CD and LHCD requirements (CD, bootstrap fraction, profile control, etc.) are now being specified. The ICRF antenna frequency range is now specified to be 80 - 120 MHz. An 8 GHz LH system is planned as an upgrade. No ECRH is planned. Outside, inside, and vertical pellet injection, capabilities are included in the design. Conceptual plans for divertor pumping on FIRE are well advanced.

For Ignitor, the LHCD and ICRH requirements need to be clarified to determine the scope of what needs to be evaluated. The ICRF frequency band is 70- 140 MHz which extends slightly above our current experience. LHCD is not currently planned for Ignitor. The LH antenna frequency that would be required is substantially higher than our current experience. ECRH is not currently planned for Ignitor. ECRH would have to be at 300-400 GHz. Outside, and vertical pellet injection, capabilities are included in the design. Ignitor has no divertor in the design.