(red = background fixed, black = beam fixed, green = background injected, blue = beam injected)
Note that twice as many beam ions are injected as background.
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Here, the original code (with beam/background, magnetic field along x)
has been modified to include particle injection.
In these runs, 4 species are used: 2 fixed and 2 injected (into either beam or background), all protons.
New array "add_no(nss)" holds the number of particles added per timestep. The following parameters are
based on those used for the resonant electromagnetic ion/ion instability described in the chapter.
Species #1: nspec = 3000, vbspec = -0.15, dnspec = 0.985, btspec = 1, anspec = 1, wspec = 1, add_no = 0
Species #2: nspec = 3000, vbspec = 9.85, dnspec = 0.015, btspec = 1, anspec = 1, wspec = 1, add_no = 0
Species #2: nspec = 3000, vbspec = -0.15, dnspec = 0.985, btspec = 1, anspec = 1, wspec = 1, add_no = 2
Species #4: nspec = 3000, vbspec = 9.85, dnspec = 0.015, btspec = 1, anspec = 1, wspec = 1, add_no = 1
All particles are initialized at t = 0 and then moved at the appropriate time. The injected particles
were initialized the same as the fixed particles except that they were assigned a random position along the
x axis.
I modified the density normalization variable FRAC to one which changes depending on the number
of particles input (renamed to FFRAC). Below are the values of FFRAC for each of the species at
the various timesteps.
Questions/Comments:
(1) The way I did this, injecting a certain number of particles per timestep results in a loading
rate which depends on timestep. This doesn't necessarily seem like a good idea in the long run. I will
modify the code to include timestep independent particle injection.
| timestep | species | FFRAC | frac in beam |
|---|---|---|---|
| 0 | 1 | 0.985 | 0.015 |
| 2 | 0.015 | ||
| 3 | 0.0 | ||
| 4 | 0.0 | ||
| 300 | 1 | 0.757692337 | ~0.088 |
| 2 | 0.0115384609 | ||
| 3 | 0.15384616 | ||
| 4 | 0.0769230798 | ||
| 600 | 1 | 0.615625024 | ~0.134 |
| 2 | 0.00937499944 | ||
| 3 | 0.25 | ||
| 4 | 0.125 | ||
| 900 | 1 | 0.518421054 | ~0.166 |
| 2 | 0.00789473671 | ||
| 3 | 0.315789461 | ||
| 4 | 0.157894731 | ||
| 1200 | 1 | 0.447727293 | ~0.189 |
| 2 | 0.00681818184 | ||
| 3 | 0.363636374 | ||
| 4 | 0.181818187 |
|
1a) Phase Space first 160 timesteps (red = background fixed, black = beam fixed, green = background injected, blue = beam injected) Note that twice as many beam ions are injected as background.
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1b) Phase Space to 1200 timesteps
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2a) By
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2b) Bz
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2c) Phi
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3) Density (all species)
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4a) Velocity Space: vx-vy
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4b) Velocity Space: vy-vz
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