Patent ID: 7728307

Claim:
Measurement method comprising the processing of a signal ( 11 ) containing a succession of main pulses ( 17 ) of duration D and energy E, spaced in time from each other and each consisting of a pile-up of elementary pulses ( 15 ) of duration Di and whose energy is evaluated by a variable Ei having an additive property, said elementary pulses ( 15 ) having times of arrival Ti which follow a homogeneous Poisson process of intensity λ, wherein the method comprises the steps of: digitizing said signal to obtain data ( 24 ) representative thereof, from said data ( 24 ): measuring the duration D and energy E of each main pulse ( 17 ) to construct Duration-Energy pairs (D,E), determining the energy pairs (Di,Ei) of the elementary pulses ( 15 ) from the constructed pairs (D,E), by solving an unpiling formula linking a function of the Duration-Energy pairs (D,E) of the main pulses with a function of the Duration-Energy pairs (Di,Ei) of the elementary pulses, said unpiling formula is of the form: ∑ t = 0 ∞ ⁢ z t ⁡ ( α t - Kt ⁡ ( s ) ) = 1 1 - ( α ⁢ ⁢ z + ( 1 - α ) ⁢ z ⁢ ⁢ B ⁡ ( z , s ) ) in which the variables z and s represent Z-transforms of durations and energies respectively, t is an integer corresponding to a duration, B(z,s) is the Z-transform of probability density b t,e , b t,e representing the probability that the duration of a main pulse is equal to the value t and its energy is equal to a value e, Kt(s) is the Z-transform of a function dependent upon the probability density h t,e , h t,e representing the probability that the duration of an elementary pulse is equal to the value t and its energy is equal to the value e, and α is a parameter dependent on the activity of the analysed source, determined using the following formula: α=exp(−λ T e ) in which Te is a sampling period associated with the digitizing step.