NICADD LCD Simulations:

1
NICADD LCD Simulations Capability Overview and
Future Plans
Guilherme Lima, Jeremy McCormick
2
Current Process Overview
Event Generation
JAS, Pandora-Pythia
stdHEP
Detector Simulation
Gismo
SIO
SIO File Server
Analysis
SIO File (remote)
JAS
Note Each arrow represents a (probable) file
transfer.
3
Event Generation

• Single Particles
• JAS SingPartGen class
• typically electrons, pions or muons
• helpful for debugging and results certification
• typical single particles E 2, 5, 10, 20, 50
  GeV
• fixed theta/phi or randomized within boundaries
• Complex Events
• pandora-pythia (TAULA, Pandora, Pythia)
• processes include E E-, Gamma Gamma, E- E-,
  E-() Gamma, Gamma E-, etc.
• multiple processes

4
Detector Simulation

• Gismo
• stdHEP input with SIO output
• C package maintained at SLAC--no longer in
  development (difficult to install and uses old
  and unsupported toolkits)
• version 3.1.1 distribution includes CLHEP
  1.4.0.0, stdHEP 4.06 and several XML libraries
  (icu, xerces, xml4c)
• Geant4 Software
• LCDG4 and LCD-Mokka in beta or alpha.
• Mokka is available for simulations and mutual
  results certification.

5
Analysis

• SIO files remotely accessible in JAS
• wired display, MC Tree, MC Table and LCD Event
• browseable database of SIO files
• LCDROOT

6
General Problems

• General Issues
• CVS, messy codebase, lack of documentation,
  manpower and expertise, many simultaneous
  demands, unclear priorities
• utter lack of in-house design docs (Road Map)
• Geometry
• XML limits customization of the detector
  geometries.
• only idealized structures with limited utility
  beyond a certain LCD design phase
• Simulator Zoo
• LCDG4 local capability only (nicadd) with no
  certification study.
• Mokka tested only on pre-defined
  detectorsnon-working Mokka geometry drivers for
  XML input LCD-Mokka from Ties has a Seg Fault in
  XML library.
• Non-projective fork of LCDG4 will be difficult
  to reintegrate into main trunk.
• Pipeline
• perl and bash scripts plus manual command-line
  work (Ex. - sftp, ftp or scp for files.)
• Job submission, event generation and detector
  simulation have little to no User Interface
  outside of the command-line.
• SIO catalog is manually updated and currently
  not up-to-date.
• Analysis tools hacked to accommodate geometry
  modifications.

7
LCDG4-related Problems

• Extending Difficult
• limited by XML format
• class structure is not well-designed
• sensitive detector and geometry code requires an
  overhaul
• Codebase
• no support for non-projective readout in main
  code trunk
• CVS is a mess.
• practically undocumented
• misuses and recodes Geant4 constructs
• coding style, including indentation and variable
  naming, is inconsistent
• unused code still compiled!
• Structural Problems
• poor class design creates major redundencies and
  inefficiencies
• supports only LCD XML file format
• lacks a coherent long-term design plan and path

8
Short-term Goals

1. LCDG4 and LCD-Mokka mutual results certification
   for identical detector geometries
2. correct text output for LCDG4 with simulated
   non-projective cell geometry in HCal
3. debugged LCDG4 running on the Fermilab cluster
4. clean up LCDG4 code remove unused code,
   document, standardize on indentation and variable
   naming conventions
5. complete CVS reorganization/reconfig, dropping
   old versions from codebase
6. study Geant4 toolkit to understand class
   structures, application scope and built in
   capabilities

9
Midterm Plans

• phase out Gismo for a Geant4-based simulator
• coherent design document for a Geant4 simulation
  package before the coding effort
• OR
• drop LCDG4 in favor of a more mature package
  such as Mokka
• LCDG4 class restructuring in SD and geometry,
  NP in Ecal, projective and non-projective
  geometries
• modify JAS to easily analyze SIO files based on
  changeable geometry formats
• plan develop tools pipeline for LCD computing
  in all 3 phases
• establish collaborative efforts with CERN and
  SLAC for LCD simulation tool development with
  Geant4
• continue to work on UI for event generation and
  simulation tools
• design better distribution and packaging system
  for NICADD LCD software and results files

10
Ambitious Long-Term Musings

• GDML parsers and translators packaged with
  Geant4
• XML format for LCD geometries should be based on
  low-level Geant4 volume objects, which GDML
  mirrors. GDML does not currently include
  sensitive detector information, and this
  capability should be either added to the format
  or included in a separate XML file, connected to
  GDML volumes by ID tags.
• STEP file input from CAD to test actual detector
  designs, also a Geant4 built-in
• translate XML/SQL formats to GDML via XSLT and
  relational mappings
• full range of tower/non-projective simulation
  with cells as reflected volumes
• XML-based application config file for
  flexibility
• "hooks" for analysis/event-gen (Geant4 has
  built-in eventgen and visualization capabilities)
• flexibility in input and output formats and
  locations (remote would be nice)
• simulator engine that can be run remotely via
  server commands (XML-RPC/CORBA/SOAP)
• local computing cluster for pipeline automation
• catalog and distribution system for software and
  simulation or event generation result files
• Event Generation, Detector Simulation and
  Analysis tools must be powerful, flexible and
  configurable.
• Would you build an LCD without blueprints? No.
  Similarly, producing good software usually
  requires a design phase.

11
References

• Pandora-Pythia
• http//www-sldnt.slac.stanford.edu/nld/new/Docs/
  Generators/PANDORA_PYTHIA.htm
• JAS http//www-sldnt.slac.stanford.edu/jas/
• Geant4 http//wwwasd.web.cern.ch/wwwasd/geant4/g
  eant4.html
• stdHEP http//cepa.fnal.gov/CPD/stdhep/
• SIO (now within LCIO) http//www-it.desy.de/phys
  ics/projects/simsoft/lcio/
• Mokka http//polype.in2p3.fr/geant4/tesla/www/mo
  kka/mokka.html
• Gismo http//www-sldnt.slac.stanford.edu/nld/new
  /Docs/Gismo/GismoInstall.htm
• LCDG4 http//nicadd.niu.edu/simulations/software
  /index.html
• fbsnghttp//www-isd.fnal.gov/fbsng/
• Mokka LCDG4 Geometries
• http//nicadd.niu.edu/jeremy/mokka-lcdg4.html
• LCD Simulation at NICADD
• http//nicadd.niu.edu/dhiman/talks/lcdg4_slac03
  _030521.pdf
• Mokka/LCDG4 Comparison http//www-conf.slac.stan
  ford.edu/lcsimworkshop/talks/mokka.pdf
• GDML http//gdml.web.cern.ch/gdml/