Compact x-ray microtomography system for element mapping and absorption imaging.
We have designed and built a compact x-ray microtomography system to perform element mapping and absorption imaging by exploiting scanning fluorescence tomography and full-field transmission microtomography, respectively. It is based on a low power microfocus tube and is potentially appropriate for x-ray diagnostics in space. Full-field transmission tomography yields the three-dimensional inner structure of an object. Fluorescence microtomography provides the element distribution on a virtual section through the sample. Both techniques can be combined for appropriate samples. Microradiography as well as fluorescence mapping are also possible. For fluorescence microtomography a small and intensive microbeam is required. It is generated using a polycapillary optic. Operating the microfocus tube with a molybdenum target at 12 W, a microbeam with a full width at half maximum lateral extension of 16 microm and a flux of about 10(8) photonss is generated. As an example of application, this beam is used to determine the element distribution inside dried plant samples. For full-field scanning tomography, the x-ray optic is removed and the sample is imaged in magnifying projection onto a two-dimensional position sensitive detector. Depending on the sample size, a spatial resolution down to about 10 microm is possible in this mode. The method is demonstrated by three-dimensional imaging of a rat humerus.
Feldkamp
J M
JM
Institut für Strukturphysik, University of Technology Dresden, D-01062 Dresden, Germany. feldkamp@physik.tu-dresden.de
Schroer
C G
CG
Patommel
J
J
Lengeler
B
B
Günzler
T F
TF
Schweitzer
M
M
Stenzel
C
C
Dieckmann
M
M
Schroeder
W H
WH
D015502:Absorptiometry, Photon / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014056:Tomography, X-Ray / Q000295:instrumentation*