SHiPGeometry::TrackersFactory Class Reference

Factory for the Trackers (straw tube tracking stations) geometry. More...

#include <TrackersFactory.h>

Public Member Functions
	TrackersFactory (SHiPMaterials &materials)
	~TrackersFactory ()=default
GeoPhysVol *	build ()
	Build the Trackers geometry.

Static Public Attributes
static constexpr int	s_nStations = 4
static constexpr int	s_nViews = 4
	stereo views per station
static constexpr int	s_nSubLayers = 2
	staggered straw layers per view
static constexpr double	s_strawRadius = 10.0
	1 cm radius (2 cm diam)
static constexpr double	s_strawLength = 4000.0
	4 m, along X
static constexpr double	s_wallThickness = 0.030
	30 µm Mylar wall
static constexpr double	s_apertureX = 4000.0
	Active aperture inside a view frame (X = straw length region, Y = pitch).
static constexpr double	s_apertureY = 6000.0
static constexpr int	s_nStraws = static_cast<int>(s_apertureY / (2.0 * s_strawRadius))
	Straws per sub-layer (aperture height / straw diameter).
static constexpr double	s_stereoAngleDeg = 2.3
	|stereo angle| per view
static constexpr double	s_frameBarX = 100.0
	frame bar width in X
static constexpr double	s_frameBarY = 100.0
	frame bar width in Y
static constexpr double	s_frameHalfZ = 22.0
	frame half-thickness in Z
static constexpr double	s_trackerMagnetZ = 86820.0
	centre, mm
static constexpr double	s_trackerMagnetHalfZ = 230.0
	half-depth, mm

Detailed Description

Factory for the Trackers (straw tube tracking stations) geometry.

Builds 4 straw tracking stations for the SHiP spectrometer. Station envelopes and z-positions follow the GDML reference / subsystem_envelopes.csv:

• Station 1: Z 83.57-84.57 m → centre 84.07 m
• Station 2: Z 85.57-86.57 m → centre 86.07 m
• Station 3: Z 92.57-93.57 m → centre 93.07 m
• Station 4: Z 94.57-95.57 m → centre 95.07 m Station envelope (GDML statbox): half 3000 × 3430 × 500 mm.

Each station envelope is filled with 4 stereo views. A view is a material frame (FairShip-style hollow rectangle) enclosing a staggered double sub-layer of straw tubes:

• Straw: 20 mm outer diameter, 4 m long, horizontal (along X).
• Wall: 30 µm Mylar; fill: Ar/CO₂ 70/30 by mass.
• View stereo angles about the beam axis Z: +2.3°, -2.3°, +2.3°, -2.3°.

The spectrometer dipole between stations 2 and 3 is a separate subsystem (see subsystems/Magnet) and is intentionally not described here.

Constructor & Destructor Documentation

TrackersFactory()

SHiPGeometry::TrackersFactory::TrackersFactory ( SHiPMaterials &  materials )

explicit

~TrackersFactory()

SHiPGeometry::TrackersFactory::~TrackersFactory ( )

default

Member Function Documentation

build()

GeoPhysVol * SHiPGeometry::TrackersFactory::build

(

)

Build the Trackers geometry.

Returns

Pointer to the container volume holding all 4 stations.

Member Data Documentation

s_apertureX

constexpr double SHiPGeometry::TrackersFactory::s_apertureX = 4000.0

staticconstexpr

Active aperture inside a view frame (X = straw length region, Y = pitch).

s_apertureY

constexpr double SHiPGeometry::TrackersFactory::s_apertureY = 6000.0

staticconstexpr

s_frameBarX

constexpr double SHiPGeometry::TrackersFactory::s_frameBarX = 100.0

staticconstexpr

frame bar width in X

s_frameBarY

constexpr double SHiPGeometry::TrackersFactory::s_frameBarY = 100.0

staticconstexpr

frame bar width in Y

s_frameHalfZ

constexpr double SHiPGeometry::TrackersFactory::s_frameHalfZ = 22.0

staticconstexpr

frame half-thickness in Z

s_nStations

constexpr int SHiPGeometry::TrackersFactory::s_nStations = 4

staticconstexpr

s_nStraws

constexpr int SHiPGeometry::TrackersFactory::s_nStraws = static_cast<int>(s_apertureY / (2.0 * s_strawRadius))

staticconstexpr

Straws per sub-layer (aperture height / straw diameter).

s_nSubLayers

constexpr int SHiPGeometry::TrackersFactory::s_nSubLayers = 2

staticconstexpr

staggered straw layers per view

s_nViews

constexpr int SHiPGeometry::TrackersFactory::s_nViews = 4

staticconstexpr

stereo views per station

s_stereoAngleDeg

constexpr double SHiPGeometry::TrackersFactory::s_stereoAngleDeg = 2.3

staticconstexpr

|stereo angle| per view

s_strawLength

constexpr double SHiPGeometry::TrackersFactory::s_strawLength = 4000.0

staticconstexpr

4 m, along X

s_strawRadius

constexpr double SHiPGeometry::TrackersFactory::s_strawRadius = 10.0

staticconstexpr

1 cm radius (2 cm diam)

s_trackerMagnetHalfZ

constexpr double SHiPGeometry::TrackersFactory::s_trackerMagnetHalfZ = 230.0

staticconstexpr

half-depth, mm

s_trackerMagnetZ

constexpr double SHiPGeometry::TrackersFactory::s_trackerMagnetZ = 86820.0

staticconstexpr

centre, mm

s_wallThickness

constexpr double SHiPGeometry::TrackersFactory::s_wallThickness = 0.030

staticconstexpr

30 µm Mylar wall

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The documentation for this class was generated from the following files:

• subsystems/Trackers/include/Trackers/TrackersFactory.h
• subsystems/Trackers/src/TrackersFactory.cpp