Improvement of Passive Material Description of ATLAS Detector for Simulation
There are several regions of the geometry used in the Geant4 simulation where volumes representing service and support structures are missing or described by insufficient detail. Moreover, volumes representing structures that will undergo modifications during the Phase-I upgrades will be changed, in particular the NSW. The work to be carried out as part of this working package is the implementation of these missing volumes and the refinement of volumes with insufficient detail.
The main objective is to establish a smooth workflow from design engineers to the implementation within the ATLAS ATHENA framework. The design geometry will be extracted from the engineering database and implemented in CATIA by adding absent drawings. Subsequently the derived 3D model will be simplified, paying special attention to preserving the initial volume and weight. A transfer into XML will be performed. The result will then be integrated into the simulation geometry with assistance from geometry and simulation experts. All detector systems will be considered in these studies, starting with the Muon Spectrometer, including the NSW, and extending to the calorimeter (and subject to further discussion the inner detector).
General list of volumes to be done:
1. ID services in sectors 3, 1 and 7 — Muon subsystem
2. Magnet services in sector 13 and 7 — Muon subsystem
3. Lar services in GAP region — Calo subsystem
4. Cables, Pipes and support structures in GAP region — Calo subsystem
5. Electrical boxes in GAP region — Calo subsystem
6. CALO services — Calo subsystem
7. Muon services — Muon subsystem
8. Racks, Cable trays — Muon subsystem
9. Platforms in sectors: 1, 3, 5, 7, 9, 11, 13, 15 — Muon subsystem
ATLAS Project(s): Muon Spectrometer and Tile Calorimeter
ATLAS contact person: Stefano Rosati and Nicolas Koehler (Muon Spectrometer); Alexander Solodkov (Tile Calorimeter)
Required effort from Georgian team: 2 FTE /CATIA designers, programmers
Georgian team contact person: 0.4 FTE
Required visits to CERN by Georgian team: 3 visits of 1-2 weeks Deliverables:
1. Technical reports of Simplification
2. Technical reports of Integration Conflicts Checking
3. XML code
4. Implementation in the simulation geometry
Support for Geant4 Baseline Geometry
Provision of support for the geometry description files, that have to-date been provided by the Georgian group, for a period of 2 years, i.e. 2021 and 2022. This support should be provided via a contact person who can answer questions and, if needed, fix small problems.
ATLAS contact person: Stefano Rosati and Nicolas Koehler Required effort from Georgian team: To be decided.
Development of AGDD Geometry Descriptions of the Cavern and Muon Spectrometer for Simulation
Simulation of radiation and background levels in an underground experiment rely heavily on an accurate description of the geometry of the detector and of the experimental hall: equally important is the chemical composition (materials) of all volumes. In particular, given the particular nature of the ATLAS muon spectrometer (an open-air toroid with very little shielding behind the calorimeters), an accurate description of the muon spectrometer and of the cavern (including access shafts, plugs and in general service infrastructures) are of paramount importance when evaluating precisely the neutron fluxes and cavern background simulation.
Whilst the geometry of the spectrometer is well understood (see WPI), the geometry of the cavern is basic in terms of detail and the code is under-maintained and inadequately documented. Furthermore, the geometry description contains volume overlap bugs, which currently block new background simulation.
The cavern geometry code should be replaced with an XML-based (AGDD) description that, while inspired by the existing one, can be fixed and developed freely by the team to cover the requirements of any background simulation (or any other connected activity such as cosmic simulation).
The team should develop:
a good knowledge of the experimental layout, including the cavern (CATIA) a good knowledge of the AGDD infrastructure
The team should work in close collaboration and consultation with:
a) the background/radiation simulation group, who have a clear understanding of the physics requirements.
b) The simulation group for the integration in the main simulation line/infrastructure.
c) The detector description group, especially regarding tools and future developments.
The team should make regular reports to the simulation and detector description group meetings and interact directly with members of those groups. Visits to CERN by members of the Georgian team working on this work package are required.
After this work is completed, the team should work closely with the simulation and detector description groups in the larger task of porting the whole of the muon spectrometer+cavern to the newly developed detector description system. New milestones for this can be defined at a later date.
ATLAS Project: Software and Computing
ATLAS contact person: Andrea Dell\'Acqua and Joseph Boudreau
Required effort from Georgian team: 3 FTE/CATIA designers, programmers
Required visits to CERN by Georgian team: 3 visits of 1-2 week duration
The timescale is envisaged as follows:
The detailed workplan is the first deliverable of this work package and will be developed by the GTU team in discussion with the ATLAS contact person and the HSF event display coordinator. As pre-requisite to this, a code review of both tools will also be undertaken requiring access to the Tracer git repository.
Once merged, further developments would include:
ATLAS Project: Software and Computing
ATLAS contact person: Edward Moyse
Required visits to CERN by Georgian team: 3 visits of 1-2—week duration Contact person contribution: 12 months
1. Provide access to the tracer git repository
2. Development of road map for the porting — 1 month
3. Generation of 1 st draft with ported functionality — 3 months
4. Further developments:
4.1. Get the existing JSON event dumper working as part of ATLAS live, so that for Run 3 it is possible to have 3D views of events in real time — 1 month
4.3. Develop a way to compress the JSON / JiveXML data, in order to reduce file sizes - 1 month
5. Generation of the 2nd draft of the merged product — end of 2020