Exponential decreasing nature of plasma density in a one dimensional slab by ambipolar diffusion

This program help to visualize the exponential decreasing nature of plasma density in a one dimensional slab by ambipolar diffusion. I have chosen the particular point at distance x = 0.01m from the slab to simulate the decay of density.


% This is a program to plot the decay of plasma by ambipolar diffusion in one dimensional slab:
clear all
close all

n_o = 1e12;          % initial density in m^-3
L = 0.024;           % length of edge from centre of the slab in m 
D = 0.4;             % ambipolar diffusion coeffecient in m^2/sec
T = (2*L/pi)^2/D;    % tau:mean time between collision

t = 0:.00002:.002;

x = .010;

n = n_o*exp(-(t./T)).*cos(pi*x./2/L);   % density distribution

comet(t,n),xlabel('t(time of decay)'),ylabel('n(density of plasma)'),
title('exponential decay of plasma dendity at position "x = .010m" of slab')

Decay of plasma by ambipolar diffusion in one dimensional slab

I have made a program using "GNU OCTAVE" to plot the decay of plasma by ambipolar diffusion in one dimensional slab.This program can be run in MATLAB also.You can know the beauty of this program only after you run this.

% This is a program to plot the decay of plasma by ambipolar diffusion in one dimensional slab:
clear all
close all

n_o = 1e12;          % initial density in m^-3
L = 0.024;           % length of edge from centre of the slab in m
D = 0.4;             % ambipolar diffusion coeffecient in m^2/sec
T = (2*L/pi)^2/D;    % tau:mean time between collision

x = linspace(-.024,.024);

for t = 0:.00002:.001;
n = n_o*exp(-(t./T)).*cos(pi*x./2/L);   % density distribution

plot(x,n),xlabel('x(slab dimension)'),ylabel('n(density of plasma)')
  axis([-0.024 0.024 0 1e12])

  pause(.1)            % pause the fig for .1 sec
end