Field Service¶

Framework-agnostic C++20 library exposing the SHiP magnetic field maps to simulation (aegir) and reconstruction (Trout).

Repository: ShipSoft/field_service

API reference: Doxygen

Field maps¶

Maps are stored in the SHiP field-map format, a versioned ROOT RNTuple layout, and evaluated with covfie (trilinear interpolation on a regular grid). A bare map filename is resolved against $SHIPFIELD_ROOT/share/field/.

Components¶

Component	Conda package	CMake target	Needs
Core: evaluators from in-memory maps	`field-service-core`	`SHiP::FieldService`	nothing from ROOT or Geant4
MapIO: read and write map files, `FieldMapSource`	`field-service-mapio`	`SHiP::FieldServiceMapIO`	ROOT
G4Adapter: `G4MagFieldAdapter`	`field-service-g4`	`SHiP::FieldServiceG4Adapter`	Geant4
ActsAdapter: `ActsFieldAdapter`	`field-service-acts`	`SHiP::FieldServiceActsAdapter`	ACTS

Request the components you need, e.g. find_package(SHiPFieldService REQUIRED COMPONENTS G4Adapter MapIO) in aegir or COMPONENTS MapIO ActsAdapter in Trout. All packages are on prefix.dev/ship-experiment/stable.

Tools¶

The field-service-tools package ships:

fairship_to_fieldmap converts FairShip's legacy ROOT field maps (use --symmetry quadrant_dipole for quadrant-symmetric maps);
fieldmap_dump prints map metadata or evaluates a map at points read from stdin;
generate_constant_fieldmap writes a uniform map for closure tests;
plot_field_map plots a map as ROOT histograms and PDFs.

Building¶

git clone https://github.com/ShipSoft/field_service.git
cd field_service
pixi run test