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Notes

March 2013

March 2013 models.

22/03/2013 Committed comi code to Launchpad Repository via Bazaar. Revision 21. (Hall Model 61)

19/03/2013 The plot autogenerator has been updated to create errB/B plots aswell as Bmod and Vector Plots. This has been tested on model 51 over the weekend and the results are now online. I will shortly try the plot autogenerator on the quad sub-models as it should now run on these with minimal tweaking. This should give some useful information for comparison with the mesh convergence runs.

I have also started solving Hall Model 61, this is pretty much identical to Hall Model 51 except that the boundary conditions have been corrected and they are now slightly further out. Boundary location is outer_air x 1.2 instead of x 1.02.

15/03/2013 Quad Model 05 - This model has been run to do a boundary comparison check with Quad Model 02. Quad Model 05 will be run with a Normal boundary condition, all other model details are identical to Quad Model 02.

14/03/2013 Please see the notes on the magnetic meeting from 12/03/2012 for details of first comparisons between the quad model 01, 02, 03 and model 51.

08/03/2013 The autogen code has been updated to generate vector plots aswell as Bmod plots. It is clear that the code will need some work to make it work with the new quad sub-models.

The Hall model has been updated so that the boundary conditions are now controlled in the comi code. This will allow us to re-run models 51-56 when the opportunity arises to see if this has fixed the problems we were observing at low field.

Committed comi code to Launchpad Repository via Bazaar. Revision 20. (Quad Sub Model 04)

07/03/2013 The first quad model compared favourably with the hall model in the vicinity of Q9, there was disagreement further up the beamline but this was understandable in the context that there was a lot of iron in the hall model to the east of Q7 that is missing in the Quad model. I was generally happy with the agreement along the beam axis.

The vector plots are also much improved with a true dipole shape being visible in the vector map even at low field level. The jury is out as to whether this is due to the change in the boundary conditions or due to the simpler model. I'm presuming the former but it will take a rerun of the hall model with the new boundary conditions to prove this.

A new variable has been added to the code that controls the meshing resolution so that the original mesh size is divided by the cube of this variable. In principle this gives a model that should have a solve time that is linearly proportional to the value of this variable. To try this out I'm now running 3 more quad models, with this variable set to 0(default mesh settings), 2 and 4. These are Quad Models 2, 3 and 4. The point of adding this variable is to make it easier to test a model for mesh convergence. A second default quad sub-model has been run as the quad sub-model air has been extended slightly.

04/03/2013 I have built the first sub-model which is intended as a model for looking more closely at the fields around the quads Q9-Q7. It is a pared down model of the MICE Hall model. Quad Sub-model 01 contains the NSW, SSW, Virostek Plates, TOF Plate, EMR, Q9 to Q7 with baseplates. This has been run at the same meshing resolution as model 51 so as to provide a direct comparison. The results in the vicinity of the quads should be comparable if the outer structures are irrelevant.

In building this model there are two issues worth pointing out:
1) A bug was found in the EMR code. A section of air was missing in the central region. Default behaviour of OPERA would have been to fill this with air so this is of minor concern but it has been fixed.
2)The Quad sub model is in control of its boundary air volume. This means that the meshing resolution, potential type, etc, have now all been fixed in the code.



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