Monte Carlo tracer particles

The block named &TRACER_PARAMS contains the parameters related to the Monte Carlo tracer particles, see Cadiou et al 2018

Overview of parameters

Variable name	Fortran type	Default value	Description
MC_tracer	boolean	.false.	Activate MC tracers
tracer_feed	string	none	Filename to read the tracer from
tracer_feed_fmt	string	ascii	Format of the input (ascii,binary or inplace)
tracer_mass	float	-1.0	Mass of the tracers, used for outputs and seed
tracer_first_balance_levelmin	integer	-1	Set to >0 to add more weight on level finer than this
tracer_first_balance_part_per_cell	integer	0	Typical initial number of parts per cell