vmec_jax.bootstrap_current

Bootstrap-current profile updates for finite-beta VMEC inputs.

The Redl bootstrap-current formula returns a flux-surface averaged parallel current, <J.B>. VMEC inputs instead take a toroidal-current profile through CURTOR and PCURR_TYPE/AC_AUX_*. This module implements the pure profile-conversion layer needed for a deterministic VMEC/Redl fixed-point iteration:

VMEC solve -> Redl <J.B> -> I(s) or I'(s) -> VMEC current profile.

The helpers here do not run VMEC. They are small, differentiable building blocks that can be tested against manufactured profiles before being used by a solve-in-the-loop driver.

Functions

apply_current_profile_to_indata(indata, *, ...)	Return a copy of indata with a VMEC current profile applied.
bootstrap_current_fixed_point(indata, *, options)	Run a VMEC/Redl fixed-point iteration for a self-consistent current.
bootstrap_current_update_to_indata(indata, *, s)	Convert a bootstrap-current update and apply it to an InData copy.
damp_current_profile(old, new, damping)	Return a damped current-profile update.
dpsi_ds_from_vmec_phiedge(phiedge, *, signgs)	Return the flux derivative convention used in the bootstrap update.
integrate_current_derivative(s, ...)	Integrate a current-derivative profile with I(0)=0.
redl_current_derivative_update(*, s, ...[, ...])	Return a VMEC current-derivative update I'(s).
redl_current_integrating_factor_update(*, s, ...)	Solve the Redl/VMEC current ODE with an integrating factor.
redl_current_rhs(*, jdotB_redl, bdotb, dpsi_ds)	Return the Redl source term for the VMEC current ODE.
vmec_current_profile_from_bootstrap_update(*, s)	Return VMEC current-profile arrays and CURTOR from bootstrap data.

Classes

BootstrapCurrentIteration(iteration, ...[, ...])	Serializable per-iteration diagnostics for bootstrap fixed points.
BootstrapCurrentOptions(helicity_n[, ...])	Configuration for Redl-to-VMEC current-profile fixed-point updates.
BootstrapCurrentResult(indata, history, ...)	Result returned by bootstrap_current_fixed_point().