TJ-II: Validation of neutral beam current drive
Experimental campaign
Spring 2022
Proposal title
Validation of neutral beam current drive
Name and affiliation of proponent
A. Cappa, S. Mulas, M. Liniers, T. Estrada, E. Ascasibar, J. Velasco et al.
Details of contact person at LNF
N/A
Description of the activity
The goal of the experiment associated to this proposal is to measure the toroidal current driven by each of the two neutral beams. To this end, it is important to achieve long NBI plasmas with stable density. Long pulses are needed to approach the current stabilization phase and stable density ensures that the time dependence of the toroidal current is mainly due to its electrodynamic evolution and is not caused by a different coupling of the beam power issued from variations in the thermal plasma parameters. Additional ECRH power can be used for density control purposes. Plasmas with co-NBI (NBI1) and counter-NBI (NBI2), as well as plasmas with balanced injection (NBI1+NBI2), will be explored. The level of optimum ECRH power will be determined depending on the operation conditions considering that moderate electron temperature (below 800 keV) are desirable to favour shorter stabilization times.
The measured toroidal current will be compared to the computational/numerical estimates of the toroidal current generated by both neutrals beams once the bootstrap current contribution is removed.
International or National funding project or entity
Include funding here (grants, national plans)
Description of required resources
Required resources:
- Number of plasma discharges or days of operation: 1
- Essential diagnostic systems: Rogowski (Ip), Scattering Thomson (ne & Te), Doppler Reflectometry (Er), ECE (Te), NPA (Ti), MSE (rotational transform)
- Type of plasmas (heating configuration): NBI plasmas with background ECRH power for density control purposes
- Specific requirements on wall conditioning if any: Density control and long pulses are critical for this proposal.
- External users: need a local computer account for data access: no
- Any external equipment to be integrated? Provide description and integration needs: N/A
Preferred dates and degree of flexibility
Preferred dates: (format dd-mm-yyyy)
References