Calculating photolysis time of AgF

How can I theoretically predict the time needed to photolyze n moles of $\ce{AgF}$? (with UV) (this is not a homework question)


The photolysis of $\ce{AgF}$ requires UV light - but I don't know which wavelength the UV must be at for the optimal photolysis. Then if the wavelength is known I can calculate the energy of one UV photon of a specific wavelength. After that I can calculate the required amounts of photons required for the reaction


I was thinking of this method:


1. First I need to find out which wavelength the UV must be at for the optimal photolysis of $\ce{AgF}$ (How?)
2. Then I need to calculate the amount of energy required for the photolysis of AgF : on wolframalpha I entered this equation: $\ce{2AgF -> 2Ag + F2}$ and it gave me a $\Delta{}H=409.2\:\mathrm{kJ/mol}$


And somehow I must be able to then figure out which lamp I could use and how long I should use it.


