Nuclear microscopy uses a device called a microprobe. A microprobe is a device that uses electromagnetic or electrostatic lenses to focus an ion beam. In this way a microprobe is very similar to a scanning electron microscope. One difference is that the nuclear microprobe's beam is usually composed of protons and alpha particles. Some of the most advanced nuclear microprobes have beam energies in excess of 2 MeV. This gives the device very high sensitivity to minute concentrations of elements, around 1 ppm at beam sizes smaller than 1 micrometer. This elemental sensitivity exists because when the beam interacts with the a sample it gives off characteristic X-rays of each element present in the sample. This type of detection of radiation is called PIXE. Other analysis techniques are applied to nuclear microscopy including Rutherford backscattering(RBS), STIM, etc.
Famous quotes containing the word nuclear:
“American universities are organized on the principle of the nuclear rather than the extended family. Graduate students are grimly trained to be technicians rather than connoisseurs. The old German style of universal scholarship has gone.”
—Camille Paglia (b. 1947)