POLAR-2: a large scale gamma-ray polarimeter for GRBs
  The prompt emission of GRBs has been investigated for more than 50 years but
remains poorly understood. Commonly, spectral and temporal profiles of
{\gamma}-ray emission are analysed. However, they are insufficient for a
complete picture on GRB-related physics. The addition of polarization
measurements provides invaluable information towards the understanding of these
astrophysical sources. In recent years, dedicated polarimeters, such as POLAR
and GAP, were built. The former of which observed low levels of polarization as
well as a temporal evolution of the polarization angle. It was understood that
a larger sample of GRB polarization measurements and time resolved studies are
necessary to constrain theoretical models. The POLAR-2 mission aims to address
this by increasing the effective area by an order of magnitude compared to
POLAR. POLAR-2 is manifested for launch on board the China Space Station in
2024 and will operate for at least 2 years. Insight from POLAR will aid in the
improvement of the overall POLAR-2 design. Major improvements (compared to
POLAR) will include the replacement of multi-anode PMTs (MAPMTs) with SiPMs,
increase in sensitive volume and further technological upgrades. POLAR-2 is
projected to measure about 50 GRBs per year with equal or better quality
compared to the best seen by POLAR. The instrument design, preliminary results
and anticipated scientific potential of this mission will be discussed.
