lattice versus strength files

[tomerten]

Ok I am going to be difficult again.

I am working with Pierre on orbit bumps to scan apertures, which made me look into my old code (python and mathematica) and definition files (aperture).

To be short:
At cern the lattice is stored in madx format, but the settings of the magnets is stored in a separate strength file (a bit similar to our power supplies but in physics units). This allows to quickly add permanent orbit bumps into the lattice (to dynamically take care of sinking detectors - yes they sink in the ground they are heavy - and steer the beams around ULOs or Unidentified Lying Objects) in the sense that the user of the lattice does not see this, even when he is changing the settings of other magnets (the bump is automatically added in madx by calling the strength files - and they are also loaded this way in the LHC sequencer when the machine is run e.g. injection optics, ramping optics - the bumps need to ramp up too - collision optics).

Such things will be part of my future standard tools and are not easy to implement on the current format of lattice json or to add it simply to the exported madx file, so again I will argue to take the numerical values of magnet strengths out and load a strength file or several strength files separately.

In my opinion, strengths are not lattice, but power supplies are - they are the hardware and not the k-values.

Let us please discuss this point in the very near future as I also need this rather quickly.