A detailed and precise study of high energy deuteron beams from a plasma focus device shows that they follow a non-power law distribution, unlike most of the other works. This is in agreement with our previous studies using a direct and unambiguous diagnostic of the activation yield-ratio technique. It is possible that the E−n dependence effectively terminates at some maximum deuteron energy. The experimental results show that the spectrum increases to very high energies whereas the power law fit fails. A unique feature of the magnetic spectrometry experimental arrangement, in this work, is that the pinhole holder also functions as a Faraday cup for time-resolved measurements of the deuteron beam.