| 摘要 |
Nondestructive analysis of a porous, inhomogeneous, generally cylindrical object, such as a soot boule (12), comprised of n known components, where n is an integer, is achieved by scanning the boule with a beam (18) comprised of photons, each having a distinct energy within one n-1 energy groups. The intensity of the photons within each of the n-1 energy groups leaving the boule is detected by a detector (22) and is measured by a pulse height/scaler analyzer (30) at each of a plurality of separate heights ti of the beam (18) as measured from the center of the boule. A computer (31) determines each of n-1 attenuation coefficients mu 1(r), mu 2(r), . . . mu n(r), representing the attenuation of the intensity of the photons in each of the n-1 energy groups, respectively, at each height ti of the beam in accordance with the output data furnished by the scaler/analyzer. From the n-1 attenuation coefficients, the computer (31) determines the density rho (r) and the respective molecular mass fractions x1(r), x2(r) . . . xn(r) of the n molecular components of the boule (12) at each height ti of the beam. |
