Details of the configuration

• Pixel layout: They are typically stored in larndsim/pixel_layouts. multi_tile_layout-2.3.16.yaml is a pixel layout file tailored for Module0 with realistic off channels/chips. multi_tile_layout-2.4.16.yaml is a generic LArPix v2a layout for a 2x2 module, and multi_tile_layout-2.5.16.yaml is a generic LArPix v2b layout for a 2x2 module. For both 2.4.16 and 2.5.16, all the channels (pixels) are activated. multi_tile_layout-3.0.40.yaml is a generic LArPix v2b/v3 layout for a ND-LAr module. .16 and .40 indicate the number of tiles. The pixel layout files provide information of channel mapping, pixel_pitch, tile_positions, tile orientation, tpc position etc. It is produced using larpix-geometry (larpixgeometry/layouts/multi_tile_layout.py for example).
• Detector properties: The detector properties are passed to the simulation through a yaml file. Examples can be found in larndsim/detector_properties. The e_field, lifetime, response sampling and response bin size can be set differently for different modules. The detector properties are loaded to larndsim/consts/detector.py and larndsim/consts/light.py.
• Simulation properties: The parameters for simulation properties are set in a yaml file typically stored in larndsim/simulation_properties. The simulation properties are loaded to larndsim/consts/sim.py.
• Response file: Response file is a look-up table for the near-field charge induction modeling. Electric field simulation with finite-element-method (FEM) is used to produce the response file. The look-up tables are typically stored in larndsim/bin. response_44.npy is for pixel with 4.4 mm pitch (LArPix v2a-like), and response_38.npy is for pixel with 3.8 mm pitch (LArPix v2b/v3-like). Note that the setting in the detector properties need to be adjusted accordingly. (To be expanded. How it is produced. Link the script used to make the configuration.)
• Light look-up table (LUT): A light LUT used in larnd-sim provides the "visibility" of photons from TPC volumes to the light readout channels. They are outputs of GEANT4 simulation of the light propagation which are stored as root files. The script here has been used to translate it into the format that larnd-sim consumes. An example of a 2x2 module light LUT can be found in larnd-sim as larndsim/bin/lightLUT.npz. Due to the file size, the latest high-resolution 2x2 light LUT are not in this repository but can be found on NERSC web portal and /global/cfs/cdirs/dune/www/data/2x2/simulation/larndsim_data/light_LUT. (To be expanded. Some description on the G4 simulation. Link the script used to make the LUT. Differences of the M0 and M123 LUT...)
• Light detector noise: An example of the light detector noise for 2x2 can be found larndsim/bin/light_noise_2x2_4mod_July2023.npy. It has the noise profile for each light readout channel, and was extracted based on the single module cosmic runs. (To be expanded. How it is produced. Link the script used to make the configuration.)
• Bad channels (optional): LArPix channels flagged as bad channels will be deactivated in the simulation. (To be expanded. How it is produced, and an example)
• Pixel thresholds (optional): The file gives channel-by-channel discriminator threshold for the charge simulation. If it is not provided, the threshold is considered to be the same for every LArPix channel, and is set by fee.DISCRIMINATION_THRESHOLD. (To be expanded. How it is produced, and an example) (Maybe the two files in larndsim/detector_properties/thresholds/ are some examples...)
• Pixel gains (optional): This configuration provides channel-by-channel gain factor for the charge simulation. If it is not given, the gain is set by fee.GAIN for all channels. (To be expanded. How it is produced, and an example)