A new way to compute charged fusion product trajectories. Application to the detection of 3 MeV protons

The paper reports recent results concerning the 3 MeV fusion proton trajectories in the Tore Supra tokamak. The orbit computations were made in a new and unusual manner on the basis of a topological equation which governs these trajectories. The method avoids both the problem of computing precision and the need to follow a large number of particles along their orbits; it permits a topological map of trajectories to be drawn, i.e. all possible trajectory classes, without any numerical computation to be found. It also gives the transitions occurring between the various classes. The confinement of the proton orbits and the optimization of the detector location were studied under the same topological rules. The need to develop this subject comes from the necessity to explain a large quantity of experimental data recorded by a silicon detector system on Tore Supra. Experimental analysis of the charged fusion products (CFP) is ensured by this unique detection system, which allows simultaneously energy and pitch angle resolution to be obtained.