Merge pull request #542 from bmad-sim/devel/step21

Devel/step21
bmad-sim · Oct 5, 2023 · 7f3a492 · 7f3a492
2 parents bcccadc + 95a0eed
commit 7f3a492
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Showing 3 changed files with 16 additions and 7 deletions.
diff --git a/bmad/doc/attributes.tex b/bmad/doc/attributes.tex
@@ -2335,7 +2335,7 @@ \subsection{Cartesian_Map Field Map}
 map types.
 
 To use with PTC dependent tracking methods (\sref{s:integ}) there are a number of restrictions:
- \begin{itemize}
+\begin{itemize}
 %
 \item
 There can be only one \vn{cartesian_map} field map and there cannot be any other field maps of any
@@ -2349,6 +2349,10 @@ \subsection{Cartesian_Map Field Map}
 %
 \item
 The transverse terms in \vn{r0} must be zero.
+%
+\item
+Since PTC evaluates the vector potential (\sref{s:wiggler.std}), and since \vn{k_z} appears in the
+denominator of some terms, \vn{k_z} must be non-negative for all terms.
  \end{itemize}
 
 %-----------------------------------------------------------------

diff --git a/bmad/ptc/ele_to_fibre.f90 b/bmad/ptc/ele_to_fibre.f90
@@ -904,8 +904,7 @@ subroutine ele_to_fibre (ele, ptc_fibre, param, use_offsets, err_flag, integ_ord
  is_planar_wiggler = ((key == wiggler$ .or. key == undulator$) .and. ele2%field_calc == planar_model$) 
 
  if (associated(ele2%grid_field)) then
- call out_io (s_fatal$, r_name, 'PTC TRACKING IS NOT ABLE TO USE GRID_FIELDS. FOR ELEMENT: ' // ele%name)
- if (global_com%exit_on_error) call err_exit
+ call out_io (s_error$, r_name, 'PTC TRACKING IS NOT ABLE TO USE GRID_FIELDS. FOR ELEMENT: ' // ele%name)
  return
  endif
 
@@ -914,18 +913,22 @@ subroutine ele_to_fibre (ele, ptc_fibre, param, use_offsets, err_flag, integ_ord
  allocate(cm)
  call create_wiggler_cartesian_map(ele2, cm)
  else
- call out_io (s_fatal$, r_name, 'NOT ABLE TO DO PTC TRACKING FOR NON-PLANAR WIGGLER WITHOUT A CARTESIAN (OR OTHER TYPE OF) MAP.', &
+ call out_io (s_error$, r_name, 'NOT ABLE TO DO PTC TRACKING FOR NON-PLANAR WIGGLER WITHOUT A CARTESIAN (OR OTHER TYPE OF) MAP.', &
  'FOR ELEMENT: ' // ele%name)
- if (global_com%exit_on_error) call err_exit
  return
  endif
  else
  cm => ele2%cartesian_map(1)
  endif
 
+ if (any(abs(cm%ptr%term%kz) < 1e-100_rp)) then
+ call out_io (s_error$, r_name, 'CARTESIAN MAP KZ VALUES MUST BE NON-ZERO (MAKE > 1E-100).', &
+ 'FOR ELEMENT: ' // ele%name)
+ return
+ endif
+
  if (cm%field_type == electric$) then
  call out_io (s_fatal$, r_name, 'PTC IS NOT ABLE TO HANDLE CARTESIAN_MAP WITH ELECTRIC FIELDS. FOR ELEMENT: ' // ele%name)
- if (global_com%exit_on_error) call err_exit
  return
  endif 
 

diff --git a/tao/code/tao_spin_polarization_calc.f90 b/tao/code/tao_spin_polarization_calc.f90
@@ -87,12 +87,13 @@ subroutine tao_spin_polarization_calc (branch, tao_branch, excite_zero, ignore_k
 if (branch%param%geometry == closed$) then
  tao_branch%spin%tune = 2.0_rp * atan2(norm2(q_1turn%spin_q(1:3,0)), q_1turn%spin_q(0,0))
  n0 = 0
+ s_vec = [0.0_rp, 0.0_rp, 1.0_rp]
  dn_dpz = 0
  partial = 0
  partial2 = 0
-
 else
  n0 = branch%lat%particle_start%spin
+ s_vec = [0.0_rp, 0.0_rp, 1.0_rp]
  dn_dpz = branch%ele(0)%value(spin_dn_dpz_x$:spin_dn_dpz_z$)
  partial = 0 ! Not sure this is computable.
  partial2 = 0
@@ -110,6 +111,7 @@ subroutine tao_spin_polarization_calc (branch, tao_branch, excite_zero, ignore_k
  old_n0 = n0
  old_partial = partial
  old_partial2 = partial2
+ old_s_vec = s_vec
 
  ele => branch%ele(ie)