Ponente
Descripción
The Trans-Iron Galactic Element Recorder (TIGER) family of instruments are designed to make the best single-element resolution measurements of the Ultra-Heavy Galactic Cosmic Rays (UHGCRs) to probe their origins and the sources of nucleosynthesis. The TIGER and SuperTIGER stratospheric long-duration balloon-borne detectors have each had two successful flights from Antarctica, with TIGER making preliminary cosmic-ray (CR) abundance measurements through $_{40}$Zr and SuperTIGER through $_{56}$Ba. Maximizing exposure is critical for observing the very rare UHGCR, which these balloon missions achieved with extended flight time and by flying the largest detector area possible. The successor to these instruments will be the TIGER for the International Space Station (TIGERISS), a NASA Astrophysics Pioneers mission with a planned 2027 launch. TIGERISS will measure the abundances of individual CR elements from $_{5}$B to $_{82}$Pb with unprecedented charge resolution and detector linearity, improving on its predecessors by using silicon strip detectors (SSDs) in place of scintillator detectors for ionization energy measurements and using silicon photomultipliers instead of photomultiplier tubes for lower-voltage and more compact read out of the acrylic and silica aerogel Cherenkov-light-radiator detectors. The superior resolution of the SSDs over the scintillator detectors has been demonstrated in component accelerator tests at CERN, allowing TIGERISS to identify UHGCR nuclei with charge resolution $\sigma_{Z}$ < 0.25. UHGCR observations cover those synthesized in stellar fusion and in s-process and r-process neutron capture nucleosynthesis, which will add to the multi-messenger effort to answer the question of the degree that r-process elements are synthesized in supernovae or neutron star merger events.
