A quantitative analysis method of neutron radiography is introduced in the paper. The principle of this method is described,and the influence of scattered neutrons on neutron radiography is analyzed using the particle transport programme MCNP. The relationship between the specimen-detector distance and scattered neutrons is also discussed. To weaken the influence of scattered neutrons,the penetrating thickness of thermal neutrons is quantitatively scaled by analyzing neutron pictures in which internal scattered neutrons have trailed off.

The imaging speed is a main character of the CCD based neutron digital radiography system.In the light of character of CCD,the principle of neutron digital radiography and optics,its calculating method was put forward. The imaging speed of SPRR-300 neutron radiography system was calculated by the method.The result was basically tallied with the value measured by experiment, the calculating method was believable.