jaxrts.ionization.planck_larkin_partition_sum

jaxrts.ionization.planck_larkin_partition_sum(g: Array, E: Quantity, T: Quantity) → Array

Planck-Larkin partition sum with a cutoff for negative energies.

\[u_i = \sum_s g_s \left(e^{-E_s / k_B T} - 1 + \frac{E_s}{k_B T}\right) \Theta(E_s)\]

See [Kremp et al., 2005] eqn 6.182.

Parameters:

• g (jnp.ndarray) – Degeneracy of each level.

• E (Quantity) – Energy of each level relative to the ionization threshold.

• T (Quantity) – Temperature.

Returns:

jnp.ndarray – Scalar partition-sum value.