= release note for the version 1.0.5 =

== initial polarization ==

In the previous version, the initial polarization vector (in case of : '''bmt_precession=1''') is : px=0, py=0, pz=1 for all particles. New data have been introduced : 

{{{
polar_x= ?
polar_y= ?
polar_z =?
}}}

to be given by the user in the file acc.dat (in $ACCELERATOR:: data).

In case of '''bmt_precession=0''' ($PARAMETER) the presence or absence of polar_x, polar_y, polar_z does not have any consequence. 

When '''bmt_precession=1''' an initial polarization vector is generated for each particle. Let be '''n''' the '''normed''' vector with the same direction as the vector  (polar_x, polar_y, polar_z), which does not need to be normed. Let be R, the norm of this last vector. The initial polarization vector is generated as a normed vector parallel to '''n''' in the same direction as '''n''' with the probability R, in the opposite direction with the probability (1-R). So, if R=1, the whole beam will be polarized in the '''n''' direction. 

The default value for (polar_x, polar_y, polar_z) is (0,0,1)

with '''load_beam=1''' the polarization can be read on the files ''electron.ini' and 'positron.ini' as three last values on each line (i.e. with the same format as in [wiki:BeamFormat beam files]

== modification of criterium for automatic grid sizing ==

('''automatic_grid_sizing=1''')

'''n_x''' and '''n_y''' will be generated in order to be close to : 8*cut_x(y)/sigma_x(y) [instead of 4*cut_x(y)/sigma_x(y)] (for a better statistics for the file [wiki:LumieeFormat lumi.ee.out])