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#include <CSCWireElectronicsSim.h>
Public Member Functions | |
| CSCWireElectronicsSim (const edm::ParameterSet &p) | |
| configurable parameters | |
| void | fillDigis (CSCWireDigiCollection &digis) |
| void | setFraction (float newFraction) |
Private Member Functions | |
| float | calculateAmpResponse (float t) const |
| virtual int | channelIndex (int channel) const |
| we code strip indices from 1-80, and wire indices start at 100 | |
| virtual void | initParameters () |
| initialization for each layer | |
| virtual int | readoutElement (int element) const |
| virtual float | timeOfFlightCalibration (int wireGroup) const |
Private Attributes | |
| float | theFraction |
| float | theWireNoise |
| float | theWireThreshold |
Model the readout electronics chain for EMU CSC wires
Definition at line 21 of file CSCWireElectronicsSim.h.
| CSCWireElectronicsSim::CSCWireElectronicsSim | ( | const edm::ParameterSet & | p | ) |
configurable parameters
Definition at line 13 of file CSCWireElectronicsSim.cc.
References CSCBaseElectronicsSim::fillAmpResponse().
: CSCBaseElectronicsSim(p), theFraction(0.5), theWireNoise(0.0), theWireThreshold(0.) { fillAmpResponse(); }
| float CSCWireElectronicsSim::calculateAmpResponse | ( | float | t | ) | const [private, virtual] |
Implements CSCBaseElectronicsSim.
Definition at line 160 of file CSCWireElectronicsSim.cc.
References funct::exp(), lumiNorm::norm, p1, and funct::pow().
{
static const float fC_by_ns = 1000000;
static const float resistor = 20000;
static const float amplifier_pole = 1/7.5;
static const float fastest_chamber_exp_risetime = 10.;
static const float p0=amplifier_pole;
static const float p1=1/fastest_chamber_exp_risetime;
static const float dp = p0 - p1;
// ENABLE DISC:
static const float norm = -12 * resistor * p1 * pow(p0/dp, 4) / fC_by_ns;
float enable_disc_volts = norm*( exp(-p0*t) *(1 +
t*dp +
pow(t*dp,2)/2 +
pow(t*dp,3)/6 )
- exp(-p1*t) );
static const float collectionFraction = 0.12;
static const float igain = 1./0.005; // volts per fC
return enable_disc_volts * igain * collectionFraction;
}
| virtual int CSCWireElectronicsSim::channelIndex | ( | int | channel | ) | const [inline, private, virtual] |
we code strip indices from 1-80, and wire indices start at 100
Reimplemented from CSCBaseElectronicsSim.
Definition at line 43 of file CSCWireElectronicsSim.h.
Referenced by fillDigis().
{return channel+100;}
| void CSCWireElectronicsSim::fillDigis | ( | CSCWireDigiCollection & | digis | ) |
Definition at line 35 of file CSCWireElectronicsSim.cc.
References CSCBaseElectronicsSim::addLinks(), CSCChamberSpecs::chamberType(), channelIndex(), CSCBaseElectronicsSim::doNoise_, CSCAnalogSignal::getBinValue(), CSCAnalogSignal::getSize(), i, CSCBaseElectronicsSim::layerId(), LogTrace, CSCBaseElectronicsSim::theBunchSpacing, CSCBaseElectronicsSim::theBunchTimingOffsets, theFraction, CSCBaseElectronicsSim::theOffsetOfBxZero, CSCBaseElectronicsSim::theRandGaussQ, CSCBaseElectronicsSim::theSamplingTime, CSCBaseElectronicsSim::theSignalMap, CSCBaseElectronicsSim::theSignalStartTime, CSCBaseElectronicsSim::theSpecs, CSCBaseElectronicsSim::theTimingCalibrationError, theWireNoise, theWireThreshold, crabWrap::threshold, and timeOfFlightCalibration().
Referenced by CSCDigitizer::doAction().
{
if(theSignalMap.empty()) {
return;
}
// Loop over analog signals, run the fractional discriminator on each one,
// and save the DIGI in the layer.
for(CSCSignalMap::iterator mapI = theSignalMap.begin(),
lastSignal = theSignalMap.end();
mapI != lastSignal; ++mapI)
{
int wireGroup = (*mapI).first;
const CSCAnalogSignal & signal = (*mapI).second;
LogTrace("CSCWireElectronicsSim") << "CSCWireElectronicsSim: dump of wire signal follows... "
<< signal;
int signalSize = signal.getSize();
int timeWord = 0; // and this will remain if too early or late (<bx-6 or >bx+9)
// the way we handle noise in this chamber is by randomly varying
// the threshold
float threshold = theWireThreshold;
if (doNoise_) {
threshold += theRandGaussQ->fire() * theWireNoise;
}
for(int ibin = 0; ibin < signalSize; ++ibin)
{
if(signal.getBinValue(ibin) > threshold)
{
// jackpot. Now define this signal as everything up until
// the signal goes below zero.
int lastbin = signalSize;
int i;
for(i = ibin; i < signalSize; ++i) {
if(signal.getBinValue(i) < 0.) {
lastbin = i;
break;
}
}
float qMax = 0.0;
// in this loop, find the max charge and the 'fifth' electron arrival
for ( i = ibin; i < lastbin; ++i)
{
float next_charge = signal.getBinValue(i);
if(next_charge > qMax) {
qMax = next_charge;
}
}
int bin_firing_FD = 0;
for ( i = ibin; i < lastbin; ++i)
{
if( signal.getBinValue(i) >= qMax * theFraction )
{
bin_firing_FD = i;
//@@ Long-standing but unlikely minor bug, I (Tim) think - following 'break' was missing...
//@@ ... So if both ibins 0 and 1 could fire FD, we'd flag the firing bin as 1 not 0
//@@ (since the above test was restricted to bin_firing_FD==0 too).
break;
}
}
float tofOffset = timeOfFlightCalibration(wireGroup);
int chamberType = theSpecs->chamberType();
// Note that CSCAnalogSignal::superimpose does not reset theTimeOffset to the earliest
// of the two signal's time offsets. If it did then we could handle signals from any
// time range e.g. form pileup events many bx's from the signal bx (bx=0).
// But then we would be wastefully storing signals over times which we can never
// see in the real detector, because only hits within a few bx's of bx=0 are read out.
// Instead, the working time range for wire hits is always started from
// theSignalStartTime, set as a parameter in the config file.
// On the other hand, if any of the overlapped CSCAnalogSignals happens to have
// a timeOffset earlier than theSignalStartTime (which is currently set to -100 ns)
// then we're in trouble. For pileup events this would mean events from collisions
// earlier than 4 bx before the signal bx.
float fdTime = theSignalStartTime + theSamplingTime*bin_firing_FD;
if(doNoise_) {
fdTime += theTimingCalibrationError[chamberType] * theRandGaussQ->fire();
}
float bxFloat = (fdTime - tofOffset- theBunchTimingOffsets[chamberType]) / theBunchSpacing
+ theOffsetOfBxZero;
int bxInt = static_cast<int>(bxFloat);
if(bxFloat >= 0 && bxFloat < 16)
{
timeWord |= (1 << bxInt );
// discriminator stays high for 35 ns
if(bxFloat-bxInt > 0.6)
{
timeWord |= (1 << (bxInt+1) );
}
}
// Wire digi as of Oct-2006 adapted to real data: time word has 16 bits with set bit
// flagging appropriate bunch crossing, and bx 0 corresponding to the 7th bit, 'bit 6':
// 1st bit set (bit 0) <-> bx -6
// 2nd 1 <-> bx -5
// ... ... ....
// 7th 6 <-> bx 0
// 8th 7 <-> bx +1
// ... ... ....
// 16th 15 <-> bx +9
// skip over all the time bins used for this digi
ibin = lastbin;
} // if over threshold
} // loop over time bins in signal
// Only create a wire digi if there is a wire hit within [-6 bx, +9 bx]
if(timeWord != 0)
{
CSCWireDigi newDigi(wireGroup, timeWord);
LogTrace("CSCWireElectronicsSim") << newDigi;
digis.insertDigi(layerId(), newDigi);
addLinks(channelIndex(wireGroup));
}
} // loop over wire signals
}
| void CSCWireElectronicsSim::initParameters | ( | ) | [private, virtual] |
initialization for each layer
Implements CSCBaseElectronicsSim.
Definition at line 23 of file CSCWireElectronicsSim.cc.
References e_SI, CSCBaseElectronicsSim::nElements, CSCLayerGeometry::numberOfWireGroups(), funct::pow(), CSCBaseElectronicsSim::theLayerGeometry, CSCBaseElectronicsSim::theShapingTime, CSCBaseElectronicsSim::theSpecs, theWireNoise, theWireThreshold, and CSCChamberSpecs::wireNoise().
{
nElements = theLayerGeometry->numberOfWireGroups();
theWireNoise = theSpecs->wireNoise(theShapingTime)
* e_SI * pow(10.0,15);
theWireThreshold = theWireNoise * 8;
}
| int CSCWireElectronicsSim::readoutElement | ( | int | element | ) | const [private, virtual] |
Implements CSCBaseElectronicsSim.
Definition at line 31 of file CSCWireElectronicsSim.cc.
References CSCBaseElectronicsSim::theLayerGeometry, and CSCLayerGeometry::wireGroup().
{
return theLayerGeometry->wireGroup(element);
}
| void CSCWireElectronicsSim::setFraction | ( | float | newFraction | ) | [inline] |
Definition at line 27 of file CSCWireElectronicsSim.h.
References theFraction.
{theFraction = newFraction;};
| float CSCWireElectronicsSim::timeOfFlightCalibration | ( | int | wireGroup | ) | const [private, virtual] |
Definition at line 185 of file CSCWireElectronicsSim.cc.
References CSCLayer::centerOfWireGroup(), LogTrace, PV3DBase< T, PVType, FrameType >::mag(), CSCLayerGeometry::numberOfWireGroups(), CSCBaseElectronicsSim::theLayer, and CSCBaseElectronicsSim::theLayerGeometry.
Referenced by fillDigis().
{
// calibration is done for groups of 8 wire groups, facetiously
// called wireGroupGroups
int middleWireGroup = wireGroup - wireGroup%8 + 4;
int numberOfWireGroups = theLayerGeometry->numberOfWireGroups();
if(middleWireGroup > numberOfWireGroups)
middleWireGroup = numberOfWireGroups;
GlobalPoint centerOfGroupGroup = theLayer->centerOfWireGroup(middleWireGroup);
float averageDist = centerOfGroupGroup.mag();
float averageTOF = averageDist * cm / c_light; // Units of c_light: mm/ns
LogTrace("CSCWireElectronicsSim") << "CSCWireElectronicsSim: TofCalib wg = " << wireGroup <<
" mid wg = " << middleWireGroup <<
" av dist = " << averageDist <<
" av tof = " << averageTOF;
return averageTOF;
}
float CSCWireElectronicsSim::theFraction [private] |
Definition at line 48 of file CSCWireElectronicsSim.h.
Referenced by fillDigis(), and setFraction().
float CSCWireElectronicsSim::theWireNoise [private] |
Definition at line 49 of file CSCWireElectronicsSim.h.
Referenced by fillDigis(), and initParameters().
float CSCWireElectronicsSim::theWireThreshold [private] |
Definition at line 50 of file CSCWireElectronicsSim.h.
Referenced by fillDigis(), and initParameters().
1.7.3