of devices provided up to now is that they require using particularly high power analog to digital converters operating at high sampling frequencies to process all the information contained in energy signal e t sufficiently fast it is here provided to modify the analog circuit located upstream of the analog to digital converter so that it only converts the information corresponding to peaks on energy signal e t further a circuit enabling to do away with the above mentioned overlap problems is provided fig6 illustrates a spectrometer comprising an electronic circuit solving this problem the device of fig6 comprises in the same way as the device of fig1 a photon detection device 1 a local electronic circuit 2 and an electronic processing circuit 3 a local circuit 2 or preamplifier delivering pulses vout t under the effect of the charge collection across the detector as a response to an interaction in the detector and an electronic processing circuit 3 arranged downstream of local circuit 2 capable of generating an energy signal e t formed by pulses having an amplitude depending on the quantity of charge collected during each interaction a first delay line circuit 26 for shifting in time a pulse vout t generated by preamplifier 2 this circuit being capable of generating a pulse time shifted by a delay u03c4 vout t u2212 u03c4 and a first subtractor 24 capable of generating the difference between pulse vout t and time shifted pulse.