- nuclear cross section
- cross section cross section n.
1. a flat plane cutting through a three-dimensional object,
usually at right angles to the longest axis of the object.
[PJC]
2. any visual representation of a {cross section[1]}, showing the internal structure of the object in the plane of the cross section; as, the technician prepared a series of MRI cross sections of the skull.
Note: Different cross sections created by different techniques may show different aspects of internal structure. Thus computerized axial tomography using X-rays shows different structures than are visualized by MRI. [PJC]
3. a thin slice of an object made by cutting it transversely; as, to view a cross section of a bacterium with an electron microscope after staining the DNA; cross sections were prepared with a microtome. [PJC]
4. a representative sample of a complex group; as, the town contained a cross section of the American population. [PJC]
5. (Physics) a measure of the probability that a nucleus will interact in a specified way with a bombarding particle, expressed as the effective area that the nucleus presents to the particle; -- called also {nuclear cross section}. [PJC]
The Collaborative International Dictionary of English. 2000.