A method for detecting radiations, comprising the following steps, implemented by a calculator connected to N detectors arranged about a radiation source, N being an integer greater than or equal to 3, each detector comprising a photomultiplier associated with a plastic organic scintillator undoped with a neutron absorber, of: - detecting, in a time window, pulse coincidences the multiplicity of which is of order 2 or higher between the electric signals provided by the photomultipliers, a pulse coincidence of multiplicity of order 2 or higher being detected when, in the time window, a first pulse is detected in the electric signal provided by the photomultiplier associated with a first scintillator, a second pulse is detected in the electric signal provided by the photomultiplier associated with a second scintillator and a third pulse is detected in the electric signal provided by the photomultiplier associated with a third scintillator; the method being characterised in that it further comprises the following steps of: - determining a first number of pulse coincidences the multiplicity of which is of order 2 or higher and the time deviation of which between the first and second pulses is included in a first time deviation window chosen to include (γ, n) and (n, n) type pairs, and exclude (γ, γ) type pairs; - determining a second number of pulse coincidences the multiplicity of which is of order 2 or higher and the time deviation of which between the second and third pulses is included in a second time deviation window chosen to include (n, n) type pairs, and exclude (γ, γ) and (γ, n) type pairs; - counting, from the first and second numbers of pulse coincidences of multiplicity of order 2 or higher, coincidences located in a time zone delimited by the first and second time deviation windows, whereby a count of (γ, n, n) and (n, n, n) type coincidences occurring in this time zone is obtained. - detecting, in a time window, pulse coincidences the multiplicity of which is of order 2 or higher between the electric signals provided by the photomultipliers, a pulse coincidence of multiplicity of order 2 or higher being detected when, in the time window, a first pulse is detected in the electric signal provided by the photomultiplier associated with a first scintillator, a second pulse is detected in the electric signal provided by the photomultiplier associated with a second scintillator and a third pulse is detected in the electric signal provided by the photomultiplier associated with a third scintillator; the method being characterised in that it further comprises the following steps of: - determining a first number of pulse coincidences the multiplicity of which is of order 2 or higher and the time deviation of which between the first and second pulses is included in a first time deviation window chosen to include (γ, n) and (n, n) type pairs, and exclude (γ, γ) type pairs; - determining a second number of pulse coincidences the multiplicity of which is of order 2 or higher and the time deviation of which between the second and third pulses is included in a second time deviation window chosen to include (n, n) type pairs, and exclude (γ, γ) and (γ, n) type pairs; - counting, from the first and second numbers of pulse coincidences of multiplicity of order 2 or higher, coincidences located in a time zone delimited by the first and second time deviation windows, whereby a count of (γ, n, n) and (n, n, n) type coincidences occurring in this time zone is obtained.