Displacement current

Illustration of a Gaussian surface around on plate of a charged capacitor to understand the displacement current appearing in Maxwell’s equations.

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% Author: Izaak Neutelings (February 2020)
\documentclass[border=3pt,tikz]{standalone}
\usepackage{physics}
\usepackage{xcolor}
\usetikzlibrary{decorations.markings}
\tikzset{>=latex} % for LaTeX arrow head
\colorlet{Ecol}{orange!90!black}
\colorlet{Bcol}{violet!90}
\colorlet{Icol}{blue!70!black}
\colorlet{gausscol}{green!40!black}
\colorlet{gausscol2}{green!45!blue}
\tikzstyle{current}=[->,Icol,thick]
\colorlet{pluscol}{red!60!black}
\colorlet{minuscol}{blue!60!black}
\tikzstyle{anode}=[top color=red!20,bottom color=red!50,shading angle=20]
\tikzstyle{cathode}=[top color=blue!20,bottom color=blue!40,shading angle=20]
\tikzstyle{gauss surf}=[gausscol,top color=green!2,bottom color=green!80!black!70,shading angle=5,fill opacity=0.4]
\tikzstyle{metal}=[top color=black!15,bottom color=black!25,middle color=black!20,shading angle=10]
\tikzstyle{mydashes}=[dash pattern=on 1 off 1]
\tikzset{
  EFieldLine/.style={thick,Ecol,line cap=round,decoration={markings,
                     mark=at position #1 with {\arrow{latex}}},
                     postaction={decorate}},
  BFieldLine/.style={thick,Bcol,postaction={decorate},decoration={markings,
                     mark=at position #1 with {\arrow{latex}},
                     mark=at position #1+0.5 with {\arrow{latex}}}},
  EFieldLine/.default=0.5,
  BFieldLine/.default=0.4}
\usetikzlibrary{3d}
\begin{document}
% CAPACITOR 3D - displacement current derivation
\begin{tikzpicture}[xscale=0.42]
  
  \def\RC{1.2}     % radius capacitor
  \def\RW{0.1*\RC} % radius wire
  \def\RA{1.6}     % radius ampere loop
  \def\D{2.6*\RA}  % distance between plates
 
 
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