Further Characterizations of Sputtered Copper Beryllium Capsules Using Confocal Micro X-Ray Fluorescence

Confocal micro X-ray fluorescence (confocal MXRF) is continuing to be explored as a method for characterizing copper and argon doped sputtered beryllium capsules. Previously demonstrated was the utility of confocal MXRF in both the two- and three-dimensional modes and overlaying the data with X-ray micro computed tomography as a method of nondestructive analysis. In this paper, the relative amount of copper dopant was measured as a function of capsule theta, examining the changes in the amounts of copper around the circumference of the capsule and comparing the relative amount of copper between capsules. A theta stage was specially constructed in order to perform line scans through the capsule wall while keeping the geometry of the measurement constant. Four capsules (one unpyrolyzed and three pyrolyzed) were examined with this method. The noise of the measurements averaged 1.43%, and differences within a capsule as a function of theta were 2.15%, with differences between capsules [approximately]13% indicating that the measurement noise was approximately half the overall variation in copper signal and far less than the measured differences between capsules. These differences in the amount of copper within a capsule and between capsules are much greater than that obtained using absorption techniques.