Energy spectrum from flux?

[penguindecay]

Hi, I've been measuring the flux of cosmic ray muons as a function of zenith angles. I have calculated the flux but do not know an equation to calculate the energy flux associated with it.

My scintillator stops muons that are and below 150MeV if that's any help

[Vanadium 50]

If you counted cosmic rays without measuring their energy, you don't have a measure of the energy flux.