Patent ID: 8575546

Claim:
A nondestructive inspection apparatus for inspecting an inside of a surface layer of a composite structure using cosmic-ray muons incoming substantially in a horizontal direction with being spin polarized by a given amount in a incoming direction, the apparatus comprising: positron/electron amount detecting means for detecting a positron/electron amount reflection-emitted having a characteristic time constant in a direction opposite to the incoming direction of the cosmic-ray muons by a decay of the cosmic-ray muons stopping inside the composite structure; and radiography data processing means for monitoring a state of a second substance, different from a first substance of the surface layer, existing inside the surface layer of the composite structure, as radiography to output, from the positron/electron amount detected in the positron/electron detecting means, wherein the positron/electron amount detecting means comprises a first detecting plate disposed on an incoming side of the cosmic-ray muons to detect a position and a path of the cosmic-ray muons to irradiate the composite structure, a second detecting plate disposed between the first detecting plate and the composite structure to detect the positron/electron amount produced by the decay of the stopping cosmic-ray muons the composite structure, and a trigger counter disposed immediately before the composite structure to select the muons, the positron/electron amount detecting means detects all positron/electron amounts reflection-emitted by the decay of two different muons, positive muons and negative muons, constituting the cosmic-ray muons stopping inside the composite structure, and the radiography data processing means comprises a discriminator to sample an input signal from the positron/electron amount detecting means at a predetermined reference clock to remove a noise component from the input signal sampled, and to select only detection signals of the muons, a field programmable gate array (FPGA), and an Ethernet connector connecting a ROM circuit to process an output signal from the discriminator and a data processing means.