Shannon is the digitisation package for the SHiP experiment. It turns the simulated hits written by aegir into per-detector digitised hit collections, which Trout then reconstructs.

Repository: ShipSoft/Shannon

API reference: Doxygen

How it works

Shannon is a set of Phlex plugins configured with Jsonnet workflows (stage digitisation):

Plugin	Role
read_sim_file	Reads the events RNTuple from an aegir output file
digitise_hits	Digitises the simulated hits per detector (upstream tagger, surround tagger, timing detector, straw tubes, calorimeter)
digitised_output_module	Writes one RNTuple per detector hit collection into a single ROOT file, plus validation histograms

Hit smearing uses a counter-based Philox generator from ship-random, seeded per event, so results are reproducible regardless of the number of threads.

workflows/digitise_hits.jsonnet reads ../aegir/fixed_target_mt_output.root and writes digitised_hits.root. Edit the paths for your own files.

Building

git clone https://github.com/ShipSoft/Shannon.git
cd Shannon
pixi run build
pixi run test
pixi run smoke     # generate a small input, run workflows/smoke.jsonnet, check the outputs

Other tasks: configure, install, clean, and clang-tidy / clang-tidy-diff for static analysis. Shannon is also packaged as shannon on the prefix.dev/ship-experiment/stable channel.