So it turns into Np, and electrons just falling into 'free new' levels and emmiting, right?
Give me a link where to read, please, if it's very easy to answer.
This is a complicated decay with many possible modes--there are one or more gamma associated with every alpha line (except, perhaps the highest energy one).
It is essentially impossible to compute the photon spectrum from first principles; they must be measured and doing so well is a delicate experiment.
241-Am emits several gamma rays, but 35.9% gamma rays will have 59.5412 keV energy that can be easily detected with a scintillation detector fitted with NaI (Tl) crystal.
The following Reference also provides various alpha energies from 241-Am.
Reference: WWW Table of Radioactive Isotopes http://ie.lbl.gov/toi/nuclide.asp?iZA=950241