DriftTimeUtil Struct Reference

Structure to expose some drift time and length functions from the CDCGeometryPar to Python. More...

#include <DriftTimeUtil.h>

Static Public Member Functions
static double	getDriftV (double driftTime, unsigned short iCLayer, unsigned short lr, double alpha=0., double theta=0.5 *M_PI)
	Get the realistic drift velocity.
static double	getDriftLength (double driftTime, unsigned short iCLayer, unsigned short lr, double alpha=0., double theta=0.5 *M_PI)
	Return the drift length to the sense wire.
static double	getDriftTime (double dist, unsigned short iCLayer, unsigned short lr, double alpha, double theta)
	Return the drift time to the sense wire.
static double	getPropTime (const WireID &wireID, double z)
	Getter for the in wire propagation time.
static double	getTimeWalk (const WireID &wireID, unsigned short adcCount)
	Returns time-walk.
static double	getMeasuredTime (const WireID &wireID, unsigned short tdcCount, bool smear)
	Returns the time measured at the readout board.

Detailed Description

Structure to expose some drift time and length functions from the CDCGeometryPar to Python.

Definition at line 22 of file DriftTimeUtil.h.

Member Function Documentation

getDriftLength()

static double getDriftLength ( double  driftTime, unsigned short  iCLayer, unsigned short  lr, double  alpha = 0., double  theta = 0.5 * M_PI  )

inlinestatic

Return the drift length to the sense wire.

Parameters

driftTime	Drift time (ns).
iCLayer	Continuous layer id.
lr	Left/Right boolean.
alpha	Incident angle (in rphi plane) w.r.t. the cell (rad).
theta	Incident angle (polar angle) (rad).

Definition at line 49 of file DriftTimeUtil.h.

      {
        return CDC::CDCGeometryPar::Instance().getDriftLength(driftTime, iCLayer, lr, alpha, theta);
      }

getDriftTime()

static double getDriftTime ( double  dist, unsigned short  iCLayer, unsigned short  lr, double  alpha, double  theta  )

inlinestatic

Return the drift time to the sense wire.

Parameters

dist	Drift length (cm).
iCLayer	Continuous layer id
lr	Left/Right boolean
alpha	Incident angle (in rphi plane) w.r.t. the cell (rad).
theta	Incident angle (polar angle) (rad).

Definition at line 66 of file DriftTimeUtil.h.

      {
        return CDC::CDCGeometryPar::Instance().getDriftTime(dist, iCLayer, lr, alpha, theta);
      }

getDriftV()

static double getDriftV ( double  driftTime, unsigned short  iCLayer, unsigned short  lr, double  alpha = 0., double  theta = 0.5 * M_PI  )

inlinestatic

Get the realistic drift velocity.

Parameters

driftTime	Drift time (ns).
iCLayer	Continuous layer id
lr	Left/Right
alpha	Incident angle (in rphi plane) w.r.t. the cell (rad).
theta	Incident angle (polar angle) (rad).

Definition at line 32 of file DriftTimeUtil.h.

      {
        return CDC::CDCGeometryPar::Instance().getDriftV(driftTime, iCLayer, lr, alpha, theta);
      }

getMeasuredTime()

static double getMeasuredTime ( const WireID &  wireID, unsigned short  tdcCount, bool  smear  )

inlinestatic

Returns the time measured at the readout board.

Parameters

wireID	wire id
tdcCount	TDC count
smear	if true result will be varied randomly

Returns

measured time (in ns)

Definition at line 120 of file DriftTimeUtil.h.

      {
        double smearing = 0;
        if (smear) {
          smearing = gRandom->Rndm() - 0.5;
        }
        double channelT0 = static_cast<double>(CDC::CDCGeometryPar::Instance().getT0(wireID));
        double measuredTime =
          channelT0 - (tdcCount + smearing) * CDC::CDCGeometryPar::Instance().getTdcBinWidth();
        if (measuredTime > 2000) {
          B2INFO("channelT0 " << channelT0);
          B2INFO("measuredTime " << measuredTime);
        }
        return measuredTime;
      }

getPropTime()

static double getPropTime ( const WireID &  wireID, double  z  )

inlinestatic

Getter for the in wire propagation time.

Parameters

wireID	wire id
z	start location of the signal propagation on the wire

Definition at line 80 of file DriftTimeUtil.h.

      {
        unsigned short iCLayer = wireID.getICLayer();
        const CDC::CDCGeometryPar& geometryPar = CDC::CDCGeometryPar::Instance();
        const CDC::CDCGeoControlPar& controlPar = CDC::CDCGeoControlPar::getInstance();
        B2Vector3D backwardWirePos =
          geometryPar.wireBackwardPosition(wireID, CDC::CDCGeometryPar::c_Aligned);
        B2Vector3D forwardWirePos =
          geometryPar.wireForwardPosition(wireID, CDC::CDCGeometryPar::c_Aligned);
        double zDistance = z - backwardWirePos.Z();
 
        // Actually are very small correction
        double stereoFactor =
          (forwardWirePos - backwardWirePos).Mag() / (forwardWirePos.Z() - backwardWirePos.Z());
 
        double distance = zDistance * stereoFactor;
        if (controlPar.getSenseWireZposMode() == 1) {
          distance += geometryPar.getBwdDeltaZ(iCLayer);
        }
        return distance * geometryPar.getPropSpeedInv(iCLayer);
      }

getTimeWalk()

static double getTimeWalk ( const WireID &  wireID, unsigned short  adcCount  )

inlinestatic

Returns time-walk.

Parameters

wireID	wire id
adcCount	ADC count

Returns

time-walk (in ns)

Definition at line 108 of file DriftTimeUtil.h.

      {
        return CDC::CDCGeometryPar::Instance().getTimeWalk(wireID, adcCount);
      }

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The documentation for this struct was generated from the following file:

• tracking/trackFindingCDC/eventdata/utils/include/DriftTimeUtil.h