Improvement in the Rigidity Resolution at Low Rigidities with the New Track Fitting Algorithm

At low rigidities (<10 GV), we have implemented a new track fitting algorithm based on the Kalman filtering technique. It more accurately accounts for energy losses and multiple scattering by charged particles, see C. Höppner, S.  Neubert, B. Ketzer, and S. Paul, Nuclear Inst. and Methods in Phys. Res., Sect. A 620, 580 (2010).

With this algorithm, the measurement of nuclei with AMS in terms of rigidity resolution was significantly improved up to ~10 GV, as shown in Figure 1. This is particularly important for the AMS anti-matter such as antideuterons and anti-He as well as the nuclei isotope analyses such as 3He/4He, 6Li/7Li, 9Be/10Be and 10B/11B.

The rigidity resolution for carbon nuclei as a function of rigidity
Figure 1. The rigidity resolution for carbon nuclei as a function of rigidity with the old method (black symbols) and the new method (red symbols)