FLArE

Simulation code for R&D of the FLArE detector

Setting up on lxplus

The LXPLUS service at CERN (lxplus.cern.ch) provides a cluster of machines for interactive computing as well as access to the HTCondor batch system for job submission. Provided you have a valid CERN computing account, you can access LXPLUS following these instructions:

1. Visit the list of services at the CERN Resources Portal, and search for boxes: LXPLUS and Linux, AFS Workspaces, EOS/CERNBox.
2. Subscribe to LXPLUS and Linux.
3. Subscribe and setup your AFS Workspaces: you can have up to 10GB in /afs/cern.ch/user/<initial>/<username> and up to 100GB in /afs/cern.ch/work/<initial>/<username>. You can set these limits from the Settings in the "AFS Workspace".
4. Subscribe to EOS/CERNBox and login to cernbox: https://cernbox.cern.ch/. This will allow you access to /eos/user/<initial>/<username> with up to 1TB of space.

Users are recommended to setup code in their AFS Workspace areas and use their EOS/CERNBox for long term data storage. A simple script is provided to setup the relevant software dependencies in the LXPLUS environment.

source lxplus_setup.sh

To compile the code

• Create a new directory to contain the executables (assume the path is /path/to/build).
• Assume the path to the source code is /path/to/source.
• To compile, you need to go to the build directory cd /path/to/build.
• And then cmake -S /path/to/source -B /path/to/build.
• Finally make.

The minimal software requirements are:

• Geant4 v4_10_6_p01c
• ROOT v6_22_06a
• HEP_HPC v0_14_01
• HDF5 v1_10_0+

These are automatially satisfied once the lxplus_setup.sh script is sourced. There is no longer an explicit GENIE dependency. However, the input GENIE ghep files need to be converted in the gst format (plain ROOT tree). The conversion can be perfomed with the native GENIE utility gntpc.

Run the simulation

Once the code has been compiled, the simulation can be run by passing a macro file to the FLArE executable:

./FLArE /path/to/macro.mac

Several examples of macros are available in the macros directory. The detector geometries can be easily imported by including one of the macros in macros\geometry_options. If no macro is passed as argument, the default is macros\vis.mac which simply displays the current geometry.

Single particles

There are several .mac macros in macros\single_particle directory: LAr_e-_mono.mac, LAr_mu-_mono.mac, etc. As denoted by the name, they're used to simulate single e-/mu-/... particles inside the FLArE volume. To run a simulation, just do ./FLArE macros/single_particle/LAr_e-_mono.mac. If you want to modify the energy you intend to simulate, modify the parameters inside the mac scripts.

Neutrino events

Neutrino events are generated by reading nu-Ar interaction vertexes from GENIE output files and transposing the final states particles in Geant4. These GENIE gst files are available for all users in \eos\user\m\mvicenzi\genie. Example macros can be found in macros: numu_genie.mac, nue_genie.mac, nutau_genie.mac.

Macro commands

Geometry

Command	Description	Default
/det/saveGdml	option for saving detector geometry in a GDML file, run before /run/initialize	false
/det/checkOverlap	check overlap of volumns during detector construction, run before /run/initialize	false
/det/addFLArE	option for adding the FLArE detector, run before /run/initialize	true
/det/addFORMOSA	option for adding the FORMOSA detector, run before /run/initialize	true
/det/addFASERnu2	option for adding the FASERnu2 detector, run before /run/initialize	true
/det/faser/addFASER2	option for adding the FASER2 detector, run before /run/initialize	true
/det/flare/addFLArEPos	position of the FLArE detector, run before /run/initialize	0 0 4300 mm
/det/flare/material	option for detector material, choose LAr or LKr, run before /run/initialize	LAr
/det/flare/module	option for tpc module option, choose single or 3x7, run before /run/initialize	single
/det/flare/field	option for setting the magnetic field value in FLArE HadCather and Muon Finder	1 T
/det/flare/useBabyMIND	option for using BabyMIND instead of the legacy FLArE HadCather and Muon Finder	false
/det/babymind/blockSequence	option for BabyMIND module sequence	|MMMMD||DMMMD||DMMMMD||MMDMMD||MMDMMD||MDMDMD||DMMMD|
/det/babymind/magnetPlateThickness	option for BabyMIND magnet plate thickness	30 mm
/det/babymind/magnetPlateSizeX	option for BabyMIND magnet plate size x	3 m
/det/babymind/magnetPlateSizeY	option for BabyMIND magnet plate size y	2 m
/det/babymind/magnetCentralPlateY	option for BabyMIND central magnet plate height (y)	1 m
/det/babymind/slitSizeX	option for BabyMIND magnet plate slit size x	2.8 m
/det/babymind/slitSizeY	option for BabyMIND magnet plate slit size y	10 mm
/det/babymind/fieldStrength	option for BabyMIND magnetic field strength	1.5 T
/det/babymind/verticalNbars	option for number of vertical bars in BabyMIND modules	16
/det/babymind/horizontalNbars	option for number of horizontal bars in babyMIND modules	96
/det/babymind/barThickness	option for BabyMIND scintillator bar thickness	7.5 mm
/det/babymind/verticalBarSizeX	option for BabyMIND vertical scintillator bar size x	21 cm
/det/babymind/verticalBarSizeY	option for BabyMIND vertical scintillator bar size y	2 m
/det/babymind/horizontalBarSizeX	option for BabyMIND horizontal scintillator bar size x	3 m
/det/babymind/horizontalBarSizeY	option for BabyMIND horizontal scintillator bar size y	3 cm
/det/babymind/magnetToScinSpacing	option for BabyMIND magnet plate to scintillator module spacing	15 mm
/det/babymind/magnetToMagnetSpacing	option for BabyMIND magnet plate to magnet plate spacing	20 mm
/det/babymind/blockToBlockSpacing	option for BabyMIND block to block spacing	30 mm
/det/babymind/blockPadding	option for BabyMIND block padding size	100 mm
/det/formosa/addFORMOSAPos	position of the FORMOSA detector, run before /run/initialize	0 0 13870 mm
/det/fasernu/addFASERnu2Pos	position of the FASERnu2 detector, run before /run/initialize	0 0 22023 mm
/det/faser/addFASER2Pos	position of the FASER2 detector, run before /run/initialize	0 0 42636 mm
/det/faser/magnetGeom	option for FASER2 magnet geometry, choose SAMURAI or CrystalPulling	SAMURAI
/det/faser/magnetField	option for setting the FASER2 magnetic field value	1 T
/det/faser/magnetWinX	option for SAMURAI magnet window size along X axis	3.0 m
/det/faser/magnetWinY	option for SAMURAI magnet window size along Y axis	1.0 m
/det/faser/magnetWinZ	option for SAMURAI magnet window size along Z size	4.0 m
/det/faser/yokeThickX	option for SAMURAI yoke thickness along X axis	1.5 m
/det/faser/yokeThickY	option for SAMURAI yoke thickness along Y axis	2.0 m
/det/faser/magnetNumber	option for number of CrystalPulling magnets	3
/det/faser/magnetInnerR	option for CrystalPulling magnet inner radius	0.8 m
/det/faser/magnetOuterR	option for CrystalPulling magnet outer radius	1.2 m
/det/faser/magnetLengthZ	option for CrystalPulling magnet size along Z axis	1.25 m
/det/faser/magnetGap	option for gap length (along Z) between CrystalPullin magnets	0.5 m
/det/faser/trackingNumber	option for number of FASER2 tracking stations in each assembly	6
/det/faser/trackingNBarsX	option for number of vertical scintillator bars (segmentation along X axis)	7
/det/faser/trackingNBarsY	option for number of horizontal scintillator bars (segmentation along Y axis)	3
/det/faser/trackingScinThick	option for scintillator bar thickness (along Z) in tracking layers	1.0 cm
/det/faser/trackingGap	option for gap length (along Z) between tracking stations, and gap to magnet	0.5 m

Event generators

Command	Description
/genie/useGenie	option for PrimaryGeneratorMessenger, set true to read neutrino interactions from GENIE
/genie/genieInput	if useGenie is true, give which .ghep.root file to read GENIE events
/genie/genieIStart	if useGenie is true, give the start position of the file to read GENIE events

Analysis

Command	Description
/histo/fileName	option for AnalysisManagerMessenger, set name of the file saving all analysis variables
/histo/saveHit	if true save information for all hits, false in default to save space
/histo/save3DEvd	if true save 3D spatial distribution of energy deposition, false in default
/histo/save2DEvd	if true save 2D spatial distribution of energy deposition, false in default
/histo/circleFit	if true run circle fitting and save information in output, false in default to save space
/histo/addDiffusion	if toy diffuse energy, if single diffuse single electron, false in default without diffusion

How to save an event display with high resolution using the DAWN Event Display

There is this tutorial for use at the October 2003 Fermilab Geant4 Tutorial.

• Add /vis/open DAWNFILE to the mac file, after running a pass of simulation you'll find a ".prim" files suitable for viewing in DAWN.
• Run ~/dune_data/app/dawn_3_91a/dawn -d filename.prim, and it will generate a high resolution picture with the format of EPS.

Some initial results

cern indico 1

cern indico 2