Patent ID: 7247857

Claim:
An apparatus ( 100 ) for detecting water on a ship's deck ( 110 ), where that the apparatus comprises: a neutron source ( 103 ) located below the surface of the ship's deck ( 110 ), and emitting fast/energy-rich neutrons ( 111 ); and a detector device ( 102 , 102 a , 102 b ) located below the surface of the ship's deck ( 110 ) and detecting thermal neutrons, characterized in that the apparatus further comprises: a light-emitting unit ( 102 b ) that emits light upon a nuclear event/reaction with a thermal neutron; a light-recording unit ( 102 a ) that emits an electrical pulse or an electrical signal ( 106 ) upon registration of a flash of light; and a moderator ( 104 ′, 104 ″) that is located below the surface of the ship's deck ( 110 ) and brakes and reflects neutrons upon collision; wherein the moderator ( 104 ′; 104 ″) is a light-conductive unit provided between the light-emitting unit ( 102 b ) and the light-recording unit ( 102 a ).