Exactly locating the beam-beam kick: locate_beam_beam(r,o,m,t,f)

In general one might know exactly where the beam-beam kick is located. This is certainly true if both rings of the collider are in PTC during the run.

write(6,*) " Using the actual location of the beam-beam kick "
call locate_beam_beam(als,o,m,t,f)
       call FIND_PATCH(t%a,t%ent,o ,m,t%bb%d,t%bb%a)
       write(6,*) " displacements "
       write(6,*) t%bb%d
       write(6,*) " angles "
       write(6,*) t%bb%a
       t%bb%PATCH=.true.
      do_beam_beam=my_true

The centre of the beam-beam kick is located at a point O(3) in the global frame. The orientation of the kick is given at M(3,3). For example, the x-direction of the beam-beam kick is given by:

$${\vec{e}}_{x}= M(1,1)\vec{i}+M(1,2)\vec{j}+M(1,3)\vec{k}$$ (9.2)

Find_patch computes the displacements and rotations necessary to place the beam-beam in the proper place.