From b9b4951ee5f7c3ab66dbc365f1a884fbc7fc9bce Mon Sep 17 00:00:00 2001
From: Remi Lehe <remi.lehe@normalesup.org>
Date: Thu, 4 Jan 2018 12:09:36 -0800
Subject: Update documentation on particle initialization

---
 Source/CustomDensityProb.cpp | 55 +++++++++++++++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 8 deletions(-)

(limited to 'Source/CustomDensityProb.cpp')

diff --git a/Source/CustomDensityProb.cpp b/Source/CustomDensityProb.cpp
index 1df3d75ad..2f6005bc2 100644
--- a/Source/CustomDensityProb.cpp
+++ b/Source/CustomDensityProb.cpp
@@ -1,13 +1,52 @@
 #include <PlasmaInjector.H>
 
-#include <iostream>
+using namespace amrex;
 
-#include <AMReX.H>
+///
+/// This "custom" density profile just does constant
+///
+Real CustomDensityProfile::getDensity(Real x, Real y, Real z) const {
+  const Real on_axis_density = params[0];
+  const Real plasma_zmin = params[1];
+  const Real plasma_zmax = params[2];
+  const Real plasma_lramp_start = params[3];
+  const Real plasma_lramp_end = params[4];
+  const Real plasma_rcap = params[5];
+  const Real plasma_rdownramp = params[6];
+  const Real plasma_rchannel = params[7];
+  static const Real re = 2.8178403227e-15; // Electron classical radius
+  static const Real pi = 3.14159265359;
 
-amrex::Real CustomDensityProfile::getDensity(amrex::Real x,
-                                             amrex::Real y,
-                                             amrex::Real z) const
-{
-    amrex::Abort("If running with a custom density profile, you must supply a CustomDensityProb.cpp file");
-    return 0.0;
+  Real r2 = x*x + y*y;
+  Real r = std::sqrt( r2 );
+
+  // Transverse part of the profile
+  Real nr;
+  if (r<plasma_rcap) {
+      nr = 1. + 1./(pi*on_axis_density*re) * r2/pow(plasma_rchannel, 4);
+  } else {
+      nr = 1. + 1./(pi*on_axis_density*re) *
+            pow(plasma_rcap, 2)/pow(plasma_rchannel, 4) *
+            (plasma_rcap+plasma_rdownramp-r)/plasma_rdownramp;
+  }
+  // Longitudinal part of the profile
+  Real nz;
+  if (z<plasma_zmin) {
+      nz = 0;
+  } else if (z<plasma_zmin+plasma_lramp_start) {
+      nz = (z-plasma_zmin)/plasma_lramp_start;
+  } else if (z<plasma_zmax-plasma_lramp_end) {
+      nz = 1.;
+  } else if (z<plasma_zmax){
+      nz = -(z-plasma_zmax)/plasma_lramp_end;
+  } else {
+      nz = 0;
+  }
+  // Combine and saturate profile
+  Real n = nr*nz;
+  if (n > 4.) {
+      n = 4.;
+  }
+
+  return on_axis_density*n;
 }
-- 
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