Method and device for radiation selective attenuation

摘要

The device comprises two miscible liquids, one in the other to achieve viscosity properties, such that selective attenuation of radiation intensity is achieved. The device for attenuating the intensity of radiation comprises spherical particles held in suspension in a mixture of at least two miscible liquids. The liquid mixture has a refractive index equal to that of the spherical particles for one of the liquids, and greater than the this for the second liquid. The two liquids are strongly polar, and the dipole moment of the mixture is greater than 1.5 Debye. The proportions of the two liquids may be such that the combined refractive index of the mixture is the same as that of the spherical particles. The spherical particles may be made of silicon, and have a diameter of the order of a micro-metre. The dynamic viscosity of the liquid at ambient temperature is greater than 10 centipoise.