Active CO2 two-phase loops for the AMS-02 tracker

The Alpha Magnetic Spectrometer AMS-02 [1]?[4] is an astro particle physics experiment running on the International Space Station (ISS; see Figure 1) since May 19, 2011. Its missions include the search for antimatter and the identifcation of the nature of dark matter. The AMS silicon tracker is the only subdetector inside the AMS permanent magnet that can detect the charge of a moving particle to distinguish an anti-particle from particle (see Table 1 for nomenclature).