### CAMB: replacing reionization history

Posted:

**February 18 2009**I'm doing research about a model with non-tanh reionization history. I already changed the function Reionization_xe in reionization.f90, but now I'm not sure about the value of ReionHist%tau_start. The comment says it's the time when xe is 'very small', how should I change it if the reionization history is not tanh anymore?

Another question is about the calculation of actual_opt_depth. I've read the subroutine inithermo but I don't understand how it's calculated. What is the theory behind this value? Any recommended readings?

Another question is about the calculation of actual_opt_depth. I've read the subroutine inithermo but I don't understand how it's calculated. What is the theory behind this value? Any recommended readings?