Make an actuator model

[eldond]

• We no longer anticipate getting a detailed actuator (gas puff) model from CFS
• We should make our own gas valve model.
  • The designer of the CFS gas valves is Chris Chrobak, who was in charge of the DIII-D gas system. So, we can try to guess what he would design. It's been hinted that using DIII-D valves as a model will be an adequate approximation.
    • DIII-D valves are described by [Bates 1984] and [Burrell 1978]. DIII-D valves work very well and the KSTAR valves are based on the DIII-D design [Kim 2013]
    • The responsible officer for the DIII-D gas system is Igor Bykov
  • There may be some pipe between the piezoelectric crystal and the inlet to the vacuum vessel.
    • DIII-D valves GASD, PFX1, PFX2, LOB1, LOB2, etc. are examples of this setup. DIII-D valves GASA, GASB, GASC, and GASE do not have significant tubing between the valve assembly and the vessel and thus produce faster responses.
    • See GA internal Engineering Physics Memo EPMde20171218gas_dribble for information about performance of DIII-D valves with extra tubing included.
• We need a transfer function between command voltage output by the PCS and gas flow rate.
  • Should be species-dependent
  • Should be sensitive to tubing length and number of bends in the pipe between valve and VV
  • Should have similar call structure to result of Make a simple actuator model for use in testing #6, or that development should be updated as needed so that APIs are similar or consistent

[eldond]

Completion by the end of 2024 January is desired.

[anchal-physics]

This has been partially addressed in ProjectTorreyPines/FusionSyntheticDiagnostics.jl#25

More features as requested will be added later.