Here, the geometry was changed from the original code such that the beam/background flowed along the z axis (instead of x) and the background B0 stays stays along x-axis (theta = 0). Changes were made only in the INIT subroutine, in the beam/background x and z velocities.
Questions/Comments:
(1) The velocity space of the ions (see last plot) shows a ring beam? or a partial ring
beam? The beam particles are given no temperature anisotropy in the beginning and they
were initialized as isotropic maxwellian. So, merely being in the presence of a perpendicular pickup geometry
cause them to form a ring beam in space? and then return to a warmer thermal distribution?
(2) For a true ring beam would I need to load the particles in the beam with a ring-beam distribution?
(but leave the background as maxwellian)
(3) This takes place in the reference frame of the moving electron fluid. Is it easily
altered to take place in the drift frame of the ions? I do not see how you set the
parameters in input.h to maintain zero current if you're in the rest frame
of the drifting background (if you are not specifying electron parameters)?
file input.h :
ntimes=800
dtwci=0.05
nx=128
xmax=256
nwrtf=200
wpiwci=10000.
nsp=2
nspec(1)=5120
nspec(2)=5120
vbspec(1)=9.85
vbspec(2)=-0.15
dnspec(1)=0.015
dnspec(2)=0.985
btspec(1)=1.
btspec(2)=1.
anspec(1)=1.
anspec(2)=1.
wspec(1)=1.0D0
wspec(2)=1.0D0
bete=1.
resis=0.
theta=0.
Phase Space (red = beam, black = core)
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By
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Bz
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Phi
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Density (beam+core)
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Velocity Space (beam only) when run past 800 timesteps, all become thermalized
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