Start documentation update.

Author: cemitch99

docs/source/usage/parameters.rst

@@ -903,6 +903,7 @@ See there ``nslice`` option on lattice elements for slicing.
     When running in envelope mode (when ``algo.track = "envelope"``), this model currently assumes that ``<xy> = <yt> = <tx> = 0``.
 
   * ``"Gauss3D"``: Calculate 3D space charge forces as if the beam was a Gaussian distribution.
+
   * ``"Gauss2p5D"``: Calculate 2.5D space charge forces as if the beam was a transverse Gaussian distribution.
 
     These models are supported only in particle tracking mode (when ``algo.track = "particles"``).
@@ -923,6 +924,17 @@ See there ``nslice`` option on lattice elements for slicing.
 
       Number of bins for longitudinal line density deposition.
 
+  * ``"2p5D"``: Space charge forces are computed in the plane ``(x,y)`` transverse to the reference particle velocity, while the transverse space charge kicks are weighted by the 
+longitudinal line density determined by charge deposition (2.5D model).  Longitudinal space charge kicks are determined by the derivative of the line charge density.
+
+    This model is supported only in particle tracking mode (when ``algo.track = "particles"``).
+  
+    This model supports the following sub-option:
+  
+    * ``algo.space_charge.charge_z_bins`` (``int``, default: ``129``)
+  
+      Number of bins for longitudinal line density deposition.
+  
 * ``amr.n_cell`` (3 integers) optional (default: 1 `blocking_factor <https://amrex-codes.github.io/amrex/docs_html/GridCreation.html>`__ per MPI process)
 
   The number of grid points along each direction (on the **coarsest level**)

docs/source/usage/python.rst

@@ -75,6 +75,7 @@ Collective Effects & Overall Simulation Parameters
         When running in envelope mode (when ``algo.track = "envelope"``), this model currently assumes that ``<xy> = <yt> = <tx> = 0``.
 
       * ``"Gauss3D"``: Calculate 3D space charge forces as if the beam was a Gaussian distribution.
+
       * ``"Gauss2p5D"``: Calculate 2.5D space charge forces as if the beam was a transverse Gaussian distribution.
 
         These models are supported only in particle tracking mode (when ``algo.track = "particles"``).
@@ -93,6 +94,15 @@ Collective Effects & Overall Simulation Parameters
 
       Number of bins for longitudinal charge density deposition (default: ``129``).
 
+      * ``"2p5D"``: Space charge forces are computed in the plane ``(x,y)`` transverse to the reference particle velocity, while the transverse space charge kicks are weighted by the
+        longitudinal line density determined by charge deposition (2.5D model).  Longitudinal space charge kicks are determined by the derivative of the line charge density.
+
+        These models are supported only in particle tracking mode (when ``algo.track = "particles"``).
+   
+   .. py:property:: space_charge_z_bins
+      
+      Number of bins for longitudinal charge density deposition (default: ``129``).
+
    .. py:property:: poisson_solver
 
       The numerical solver to solve the Poisson equation when calculating space charge effects.