Antiprotonic stereography
The anti Protonic Stereographie (switch) is a hypothetical imaging and therapeutic method. In the ASTER, antiprotons are first shot in a beam into the body and annihilate there after they have been captured by atomic nuclei. The products of annihilation , the pions , can be used to determine the location of the decay. When the energy of the incident antiprotons changes, the annihilation site also changes. The density between the two locations can be calculated directly from the measurement of the change . This allows you to take a three-dimensional image in any volume .
Since the energy loss of the antiprotons in matter is inversely proportional to the square of the velocity, the antiproton emits most of its energy at the end of its trajectory. This creates a very sharp Bragg peak . This fact can be exploited to use ASTER in radiation therapy , since, in contrast to X-rays, the volume in which the energy is released can be precisely determined. The advantage over the therapy with protons or ions is the simultaneous imaging of the tissue.
At present, antiprotons can only be generated at a few particle accelerators .
