# qrp¶

ChiantiPy.tools.util.qrp(z, u)[source] [edit on github]

Calculate $$Q_R^{\prime}(Z,u)$$, where $$u=\epsilon/I$$ is the impact electron energy in threshold units, from Eq. 2.12 of [R53].

Parameters: Atomic number u : array-like Impact electron energy in threshold units. q : array-like 1s ionization cross-section, $$Q_R^{\prime}(Z,u)$$

Notes

Used for calculations of direct ionization cross-sections of the H and He sequences in ChiantiPy.tools.io.twophotonHRead and ChiantiPy.tools.io.twophotonHeRead, respectively.

References

 [R53] (1, 2) Fontes, C. et al., 1999, PhRvA, 59, 1329