History x-y mechanics Needs mapping to r- trigger towers Optimised Any-5 Swiss cross Current

Endcap Map In ORCA ee_map_133.dat Text file format –Supercrystal number –crystal number –phi tower –Eta tower ages/numbering/numbering.htm Top right hand quadrant of positive z endcap as seen from the back i.e. looking towards the interaction point.

Sides meet here at a right angle Numbering within supercrystal

Generating other quadrants Supercrystal rotation is rotated in each quadrant Trigger pattern is rotated ORCA implementation is not quite correct.

Generating second Dee With respect to the trigger tower definition the two dees would look identical if place side by side. i.e. one dee is obtained from the other by rotating about the y=0 axis. Code to plot both endcaps from ORCA in the standard colours has been developed but is not yet in the ORCA release

Numbering Schemes Purpose –For construction? –For reconstruction? For construction –Needs to reflect the mechanics For reconstruction –Simple navigation from one super-crystal to the next

Construction v Reconstruction Different demands may require that we have two numbering schemes Where is the interface?

Numbering within supercrystal At the initial construction stage all supercrystals look the same –They dont know which way up they will be installed. At the construction stage the crystal numbering within supercrystals should be the same. In preliminary discussions in the UK it was felt that SC numbering within the supercrystal should be consistent at all stages.

Construction Biased SC Numbering Scheme This proposed scheme is based on the 100 channel boxes Supercrystals with adjacent numbers are connected into the same box Partials which fill in spare slots have large numbers. Partials 149(10) (10) (10) (5) (1) )

Reconstruction Biased Numbering Scheme Use the x-y grid Last year I suggested numbering out from the beam pipe in x and y with negative numbers. Similar proposal from Jeremy Mans but with crystals numbered from across the entire endcap and negative numbers indicating negative endcap.

Conclusion We may well need more than on numbering scheme We need to define the interface and make sure it is properly validated –ORCA has been slightly wrong for a long time