Thursday, March 29, 2007

Back to CTIP-type

Ok, still need to adjust the NDenses:
electron - common blocks, declarations, pdf, adjustments, selection - done!
strike - common blocks, declarations, pdf, adjustments, selection - done!
proton - common blocks, declarations, files, arrays, outputs - done!
proton1 - common blocks, declarations, files, arrays, outputs - done!
selectron - common blocks, declarations, pdf, adjustments, selection - done!
recoil - common blocks, declarations, pdf, adjustments, selection - done!
back - common blocks, declarations, pdf, adjustments, selection - done!
hit - common blocks, declarations, pdf, adjustments, selection - done!

But does it all compile? Yep.

Now I have a model with O, O2 and N2 being struck by incoming electrons, with no magnetic effects, as desired. However, this model contains old MSIS number densities. To convert to CTIP type completely, I need the CTIP densities in there as well as the altitude range.

The list of subroutines is:
randgen - no change
atom - no change
cross - no change
electron - changes
strike - changes
proton - changes
proton1 - changes
selectron - changes
recoil - changes
back - changes
hit - changes

Curent state of the input files:
NDens0 - Changes
NDens1 - Changes
NDens2 - Changes
NDens3 - Changes
Temp - Changes

...although I fear I may require one or two other pressure levels for expansion... we shall see...

ok, lets 'ave a look.

We're going from 1-600km to 80-580km, a change from 600 to 501 altitude levels.

Ok, changes in input files:
NDens0 - number of levels altered
NDens1 - CTIP numbers in
NDens2 - CTIP numbers in
NDens3 - CTIP numbers in
Temp - CTIP numbers in

Easy to follow...

So, subroutines:
electron - declarations, altitude incrementation, recording - done!
strike - declarations, alt. inc., recording - done!
proton - declarations, orientation adjustment, output - done!
proton1 - declarations, orientation adjustment, output - done!
selectron - declarations, alt. inc., recording - done!
recoil - declarations, alt. inc., recording - done!
back - declarations, alt. inc., recording - done!
hit - declarations, alt. inc., recording - done!

Compilation stuff - compiled first time

suspicious...

Quick test. 1keV gives 100+ km peak, sounds fine.

Another quick test. 10keV gives peak around 90km.

Yet another quick test. 30keV gives peak above 80km.

Seems ok so far.

100eV peaked - if that's the word - at about 130km. 50eV above it.

All the alts should be a little low as its a winter solstice atmosphere. They are indeed a little low, but not by too much in comparison to the atmospheric motion (we've lost about 20km cf the msis density height). Hmmm. Seems to work. For the really high energy stuff, I should add a lower atmospheric bin that can take the additional levels of precipitation and hold them for later uses (ie, total number of ionisations/excitations etc should remain equal as the atmosphere expands/contracts etc). Of course, further reasons for them being lower include the lack of mirroring or any pitch angle effects in there, plus no tilted field lines, as would be normal. Yep, a quick run raises the 1keV peak by nearly 10km when including the tilt. A pa spectru shouldn't be as significent a raise, but including mirroring and expansion, I think it's a pretty safe bet that the model's ok.

So, now I have a 'working' model, I can ruin it. I mean, use it. I need to feed through about a million electrons of each of the 19 DMSP levels. For the upper energies, this can be done immediately as they'll thermalise in the atmosphere above the lower boundary. For the high energy stuff, I'll need a lower atmosphere to help ascertain how much total ionisation there is - and the energy expended in creating it. Usefull here is the secondary/primary split, which tells me what the primary beam is doing and what the secondary beam then does. Changes in the primary beam affect the secondary beam - this is of paramount importance in the really high energy stuff. Not sure I'll actually use it here though...

We require:
31, 46, 66, 96, 140, 206, 300, 440, 650, 950, 1380, 2030, 2980, 4400, 6400, 9400, 14000, 20800, 30500eV runs.

Hmmm, should validate this thing soon... beyond the wishy washy validations and the validations of other near identical models. This one's new and has a defined purpose... plus it predates the arrival of the protonic version that should seal my fate...

It is total energy flux devoted to ionisation that needs to be conserved, so, in effect, it doesn't matter what the lower atmospheric composition is, just how many wallops I get from it... and from what in it... (in the case of those electrons of low enough energy to care).

Now, asides from anything else, I need to plot out what should happen for the proton version. I require:
O, O+, O-, O2, O2+, O2-, N2, N2+, N2-, H, H+, H-, e-
...and a grid of cross-sections between each of them and themselves, each one equivalent to the size of the e- grid.

Frightening innit. And that's just a 'surface' (as in scratching the) model... A proper one would involve everything down to bare nuclei, plus N stuff etc. But could be a way to start off DICE as a proper thing...

Ok, a real 'surface' model would just take the primary beam ionisations, but that wouldn't be any fun, would it?

Now a more interesting example would be could I construct a series of models similar to the electron one, but for each of the proton constituents (H, O, O2, N2), then find a way to coadd the resultant primary beams one by one?

That's it for today

Also sketched out an outline for the chapter relevant to this stuff

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