Notes

Naming

• X stands for spectrometer name:
  • h for HMS
  • p for SHMS
  • s for SOS
• Y stands for plane name.
• N stands for sequential number

Constants

• raddeg = 3.14159265/180
  • Conversion from degrees to radians.
  • real
  • DBASE/general.param
• cminch = 2.54
  • Conversion from inches to cm.
  • real
  • DBASE/general.param

Tracking

• Xsel_using_scin = 0
  • Use scintillator for track selection.
  • {0, 1} bool
  • THcHallCSpectrometer::fSelUsingScin

Drift chambers

Xdc.param

• Xdc_num_chambers
  • Number of drift chambers in detector.
  • int
  • THcDC::fNChambers
• Xdc_num_planes
  • Total number of drift chamber planes in detector.
  • int
  • THcDC::fNPlanes
• Xdc_plane_names
  • Names of planes.
  • string
  • THcDC::Setup::planenamelist
• Xdc_chamber_planes
  • Index of chamber that each plane belongs to. Chamber number starts with 1.
  • [int]
  • THcDC::fNChamber
• Xdc_nrwire
  • Number of wires in each plane.
  • [int]
  • THcDC::fNWires

Xdc.pos

• Xdc_xcenter

  • x position in cm of center for each wire chamber.
  • [double]
  • THcDC::fXCenter

• Xdc_ycenter

  • y position in cm of center for each wire chamber.
  • [double]
  • THcDC::fYCenter

• Xdc_N_zpos

  • z position in cm of center for each wire chamber.
  • double
  • internal only

• Xdc_N_roll

  • Roll in degrees for each wire chamber. Added to Xdc_alpha_angle.
  • double
  • internal only

• Xdc_N_pitch

  • Pitch in degrees for each wire chamber. Added to Xdc_beta_angle.
  • double
  • internal only

• Xdc_N_yaw

  • Yaw in degrees for each wire chamber. Added to Xdc_gamma_angle.
  • double
  • internal only

• Xdc_central_wire

  • Wire number of center of wire chamber for each plane. Basically, this is number of imaginary wire, that would cross center of plane. Wire numbers start with 1.
  • [double]
  • THcDC::fCentralWire

• Xdc_pitch

  • Distance between wires for each plane in cm.
  • [double]
  • THcDC::fPitch

• Xdc_wire_counting

  • Order in which wires are counted in each plane.
    • Xdc_wire_counting == 0 : center = (wire - Xdc_central_wire) * pitch
    • Xdc_wire_counting == 1 : center = (Xdc_nrwire + 1 - wire - Xdc_central_wire) * pitch
  • [{0, 1}]
  • THcDC::fWireOrder

• Xdc_zpos

  • Position along z in cm of each plane measured from focal plane.
  • [double]
  • THcDC::fZPos

• Xdc_alpha_angle

  • Angle \alpha of wires for each plane in radians. Basically the angle of the wires. See also link.
  • [double]
  • THcDC::fAlphaAngle

• Xdc_beta_angle

  • Angle \beta of wires for each plane in radians. See also link.
  • [double]
  • THcDC::fBetaAngle

• Xdc_gamma_angle

  • Angle \gamma of wires for each plane in radians. See also link.
  • [double]
  • THcDC::fGammaAngle

Xdc_tracking.param

• Xdc_sigma
  • Sigma of wire chamber resolution for each plane.
  • [double]
  • THcDC::fSigma
• Xdc_tdc_min_win
• TDC window lower limit for each plane.
  • [int]
  • THcDC::fTdcWinMin
  • Xdc_tdc_max_win
• TDC window higher limit for each plane.
  • [int]
  • THcDC::fTdcWinMax
  • Xdc_tdc_time_per_channel
• Conversion factor from TDC clicks to ns.
  • CAEN 1190 : 100 ps/click
  • double
  • THcDC::fNSperChan
• Xdc_plane_time_zero
  • Zero time correction for each plane in ns that is added to TDC time.
  • [double]
  • THcDC::fPlaneTimeZero
• Xdc_wire_velocity
  • Wire velocity.
  • double
  • THcDC::fWireVelocity
• Xdc_central_time
  • Used for wire velocity correction in each plane.
  • [int]
  • THcDC::fCentralTime
• Xdc_drifttime_sign
  • Used for wire velocity correction in each plane.
  • [{-1, 1}]
  • THcDC::fDriftTimeSign
• Xdc_fix_lr
  • Used for wire velocity correction in each plane.
    • Let hit have different L/R assignment for different space point.
    • Should be 0 to mimic ENGINE behavior but 1 for more correct behavior.
  • {0, 1} bool
  • THcDC::fFixLR
• Xdc_fix_propcorr
  • Used for wire velocity correction in each plane.
    • Do propagation along wire each time hit appears in a space point.
  • {0, 1} bool
  • THcDC::fFixPropagationCorrection

Velocity correction

The velocity correction is the distance from the center of the wire divided by the velocity of propagation times Xdc_drifttime_sign(plane). +/-1 for disc. card at +/- coord. (i.e. top = -x direction, so top readout is +1)

Xdriftmap.param

Contains lookup table for drift time.

• Xdriftbins
  • Number of bins in table.
  • int
  • THcDriftChamberPlane::ReadDatabase::NumDriftMapBins
• Xdrift1stbin
  • Time of first bin in ns.
  • double
  • THcDriftChamberPlane::ReadDatabase::DriftMapFirstBin
• Xdriftbinsz
  • Bin size in ns.
  • double
  • THcDriftChamberPlane::ReadDatabase::DriftMapBinSize
• XwcYfract
  • Drift time lookup table entries for plane Y.
  • [double]
  • THcDriftChamberPlane::ReadDatabase::DriftMap

Deprecated

• Xdc_num_deadwires

  • Number of dead wires in drift chambers (< 20 % efficiency)
  • int

• Xdc_deadwire_plane

  • Plane number for each dead wire.
  • [int]

• Xdc_deadwire_num

  • Wire number for each dead wire.
  • [int]

• Xdc_card_no

  • Index of connector card for each wire.
    • Single array for all planes.
    • Wires start with plane 1, wire 1.
    • For each plane there must be 'max number of wires' entries.
  • [int]

• Xdc_card_delay

  • Cable delays for each connector card.
  • [int]