Updated POLARIS code with detailed grain alignment physics and radiative torques disruption - a tool for synthetic dust polarization and modeling grain dynamic in star-forming regions.

The source code is the extended version of the public POLArized RadIation Simulator code (POLARIS ) released by Reissl et al. (2016). The improvement aims for a better understanding of the physics of grain alignment in the strong gaseous damping, star-forming regions, and provides more accurate synthetic polarized dust emission for observational constrain toward the innermost region around the protostar in the ALMA era.

The updated POLARIS code includes:

• Modelling of the grain internal alignment by Barnett relaxation and inelastic relaxation
• Modeling of the magnetic alignment by radiative torques (RATs) and enhanced Magnetic RAdiative Torques (MRAT) mechanism.
• Modeling the grain disruption by RAdiative Torque Disruption (RATD), followed by the self-calculation of the new grain size distribution by RATD and the effect of RATD on dust polarization.

Given the input of the iron configuration and the maximum tensile strength of dust grains, the updated version of POLARIS works as a reliable platform for connecting the grain physical properties - theory of grain alignment/disruption - synthetic modeling of polarized dust emission - observations of dust polarization.