Patent ID: 7361907

Claim:
A process for defining a probability of detection by a detector of traces of nuclear particles for nuclei of different types, the process comprising: identifying angles of incidence (θ ic ), (θ ic1 ) and (θ ic2 ) of alpha particles of energy (Ei) emitted by the nucleus and reaching the detector; detecting the angles of revelation of the detector; determining a relation between the angle of incidence (θ i ) of the particles on the detector and the angle of revelation (θ c ) of the detector for values (h) characterizing an intersection between the angle of incidence of the particular on the detector and the angle of revelation of the detector; obtaining either zero intersections or two intersections for each of the values (h) and which correspond to a maximum energy (E max ) and a minimum energy (E min ) that are detectable in oblique incidence of the particles for each of the values (h); identifying and evaluating intersection surfaces {S(θ ic )∩S(R)} and {S(θ ic1 ,θ ic2 )∩S(R) } representing respectively the intersection surfaces between the surface described by the angle (θ ic ) on a plane of the detector and that of the detector at a radius (R) and the intersection surface between a surface described by a ring limited by the angles (θ ic1 ) and (θ ic2 ) on the plane of the detector and that of the detector at the radius (R), a residual energy of the alpha particle of energy Ei emitted by the nucleus at a height (h) of the plane of the detector is in an interval E min ≦E ind ≧E max such that particles are emitted under angles between (θ ic1 ) and (θ ic2 ) for which E ind >E max , a proportion of the particles emitted by a nucleus located in a position of coordinates (r,h) and under angles of incidence below a critical angle of incidence (θ ic ) which reach the detector is a ratio between a surface defined by the surface S(θ ic ) described by the angle (θ ic ) on the plane of the detector and the surface S(θ ic ) described by the angle (θ ic ) on the plane of the detector defined by { S ⁡ ( θ ic ) ⁢ S ⁡ ( θ ic ) ⁢ S ⁡ ( R ) S ⁡ ( θ ic ) } ⁢ ⁢ and ; determining a function P i (r,h) expressing the probability of detection by the detector of traces of nuclear particles for each type of nucleus emitting the alpha particles of energy Ei for E min ≦E ind ≦E max in which P i ⁡ ( r , h ) = 1 - cos ⁢ ⁢ θ ic ( 1 - cos ⁢ ⁢ θ ic 2 ) ⁢ { S ⁡ ( θ ic ) ⋂ S ⁡ ( R ) S ⁡ ( θ ic ) } in which S(θ ic )=π R c 2 ,R c =h·tg (θ ic ).