1. Clash Cleanup and Cutout Implementation Dennis Wright ATLAS Muon Week 9 June 2008

2. Outline ● Clashes removed since April – toroid feet – fine-clash flag – barrel chambers ● Cutout implementation – chambers with MDTs – method of implementation – ongoing problems 2

3. Clashes removed since April ● FeetToroidBuilderRDB.cxx: – fixed incorrect z placement of vertical feet plates – were too close together causing clash with BOG cutout chambers – now have agreement with Oracle and amdb ● Fine-clash flag – earlier fix to remove clashes between chamber envelopes was seen to cause big slowdown in reconstruction code (Thomas Kittelmann) – due to the addition of tubes to chamber mother volume – flag added to turn off this fix for reconstruction (Stefania) – switch from tubes to boxes will help a little 3

4. Clashes removed since April ● Spacer beams (LB, CRO, CMI, CHV) – some cross beams were too long to fit inside cutout BOG chambers ● protruding daughter volume – long beams (LB) were too short ● did not extend past CHV and CRO – no holes in cross beams to accommodate LB's ● also no way to communicate hole location to cross beam construction methods – construction of beam geometry seemed unnecessarily complex ● I-shaped mother volume constructed which was then filled with several pieces 4

5. Clashes removed since April ● Spacer beam fixes – code added to MuonChamber.cxx to get correct cross beam position and location within BOG – used AMDB values for long beams lengths and added holes in all cross beams ● new class written, CbmComponent, to hold LB hole positions and transmit them to cross beam construction ● DBReader.h modified to include new component class – construction of beam geometry now done by simple subtraction of two side boxes from central box ● many fewer volumes now 5

6. Cutout Implementation ● Cutouts now implemented for all chambers with MDTs ● Method: – use GeoCutVolAction for RPCs and DEDs ● class propagates cutouts in mother volume down to all daughters ● OK for above components because there aren't many sub- volumes – must handle MDTs differently to avoid creating too many boolean volumes ● re-write Mdt.cxx and parts of MultiLayer.cxx in order to generalize MDT cutouts to other cutout chambers besides BOGs ● Testing of cutouts in progress – improvements in AMDB required in order to continue 6

7. Cutout Implementation ● Ongoing problems: – visual cutouts ● apparently two types of cutouts used, visual and detailed ● some redundancy between the two ● can we make one type of cutout serve both needs? – CSCs with cutouts ● not yet looked at – AMDB improvements required ● testing of cutouts has revealed problems with how they are described in AMDB ● many cutouts seem to occur outside the volume of their respective component ● some cutouts appear in AMBD where none seem to be needed 7