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
SIO File (remote)
JAS
Analysis
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

• LCDG4 and LCD-Mokka mutual results certification
  for identical detector geometries
• correct text output for LCDG4 with simulated
  non-projective cell geometry in HCal
• debugged LCDG4 running on the Fermilab cluster
• clean up LCDG4 code remove unused code,
  document, standardize on indentation and variable
  naming conventions
• complete CVS reorganization/reconfig, dropping
  old versions from codebase
• 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/