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Modified for isotropic Mu in TF.

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This commit is contained in:
nemu 2012-10-16 18:04:07 +00:00
parent e9e6c9b2e3
commit 8f057d9967
3 changed files with 69 additions and 30 deletions
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52
src/tests/MuTransition/PSimulateMuTransition.cpp
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@ -18,8 +18,8 @@
(analogous to MuBC in Si, B||(100)), a non-precessing signal, and two precessing
states ("nu_12" and "nu_34").
Parameters:
1) Precession frequencies of "nu_12" and "nu_34"
2) fractions of nu_12, nu_34
1) Precession frequencies of "nu_12", "nu_34", "nu_23", "nu_14"
2) fractions of nu_12, nu_34; and nu_23 and nu_14
3) total Mu0 fraction
4) electron-capture rate
5) Mu ionization rate
@ -91,8 +91,10 @@ PSimulateMuTransition::PSimulateMuTransition(UInt_t seed)
}
fNmuons = 100; // number of muons to simulate
fMuPrecFreq1 = 4463.; // vacuum Mu hyperfine coupling constant
fMuPrecFreq2 = 0.; // Mu precession frequency of a 2nd Mu transition
fMuPrecFreq34 = 4463.; // vacuum Mu hyperfine coupling constant
fMuPrecFreq12 = 0.; // Mu precession frequency of a 12 transition
fMuPrecFreq23 = 0.; // Mu precession frequency of a 23 transition
fMuPrecFreq14 = 0.; // Mu precession frequency of a 14 transition
fBfield = 0.01; // magnetic field (T)
fCaptureRate = 0.01; // Mu+ capture rate (MHz)
fIonizationRate = 10.; // Mu0 ionization rate (MHz)
@ -128,8 +130,10 @@ PSimulateMuTransition::~PSimulateMuTransition()
*/
void PSimulateMuTransition::PrintSettings() const
{
cout << endl << "Mu precession frequency state1 (MHz) = " << fMuPrecFreq1;
cout << endl << "Mu precession frequency state2 (MHz) = " << fMuPrecFreq2;
cout << endl << "Mu precession frequency 12 (MHz) = " << fMuPrecFreq12;
cout << endl << "Mu precession frequency 34 (MHz) = " << fMuPrecFreq34;
cout << endl << "Mu precession frequency 23 (MHz) = " << fMuPrecFreq23;
cout << endl << "Mu precession frequency 14 (MHz) = " << fMuPrecFreq14;
cout << endl << "B field (T) = " << fBfield;
cout << endl << "Mu+ electron capture rate (MHz) = " << fCaptureRate;
cout << endl << "Mu ionizatioan rate (MHz) = " << fIonizationRate;
@ -239,6 +243,10 @@ Double_t PSimulateMuTransition::PrecessionPhase(const Double_t &time, const Doub
* at the capture event. Calculate muon spin precession.
* 4) get the next electron capture time, continue until t_d is reached.
*
* <p> For isotropic muonium, TF:
* nu_12 and nu_34 with equal probabilities, probability for both states fMuFractionState1
* ni_23 and nu_14 with equal probabilities, probability for both states fMuFractionState2
*
* \param muonString if eq. "Mu+" begin with Mu+ precession
*/
void PSimulateMuTransition::Event(const TString muonString)
@ -278,10 +286,18 @@ void PSimulateMuTransition::Event(const TString muonString)
frac2 = 1. - fMuFractionState2;
if ( rndm < frac1 )
muoniumPrecessionFreq = 0.;
else if (rndm >= frac1 && rndm <= frac2)
muoniumPrecessionFreq = fMuPrecFreq1;
else
muoniumPrecessionFreq = fMuPrecFreq2;
else if (rndm >= frac1 && rndm <= frac2){
if (fRandom->Rndm() <= 0.5)
muoniumPrecessionFreq = fMuPrecFreq12;
else
muoniumPrecessionFreq = fMuPrecFreq34;
}
else{
if (fRandom->Rndm() <= 0.5)
muoniumPrecessionFreq = fMuPrecFreq23;
else
muoniumPrecessionFreq = fMuPrecFreq14;
}
if (fDebugFlag) cout << "Ioniza. time = " << ionizationTime << " Freq = " << muoniumPrecessionFreq
<< " Phase = " << fMuonPhase << endl;
@ -303,10 +319,18 @@ void PSimulateMuTransition::Event(const TString muonString)
frac2 = 1. - fMuFractionState2;
if ( rndm < frac1 )
muoniumPrecessionFreq = 0.;
else if (rndm >= frac1 && rndm <= frac2)
muoniumPrecessionFreq = fMuPrecFreq1;
else
muoniumPrecessionFreq = fMuPrecFreq2;
else if (rndm >= frac1 && rndm <= frac2){
if (fRandom->Rndm() <= 0.5)
muoniumPrecessionFreq = fMuPrecFreq12;
else
muoniumPrecessionFreq = fMuPrecFreq34;
}
else{
if (fRandom->Rndm() <= 0.5)
muoniumPrecessionFreq = fMuPrecFreq23;
else
muoniumPrecessionFreq = fMuPrecFreq14;
}
if (fDebugFlag)
cout << "Mu Ioniza. time = " << ionizationTime << " Freq = " << muoniumPrecessionFreq

12
src/tests/MuTransition/PSimulateMuTransition.h
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@ -49,8 +49,10 @@ class PSimulateMuTransition : public TObject
virtual void SetNmuons(Int_t value) { fNmuons = value; } //!< number of muons
virtual void SetDebugFlag(Bool_t value) { fDebugFlag = value; } //!< debug flag
virtual void SetBfield(Double_t value) { fBfield = value; } //!< sets magnetic field (T)
virtual void SetMuPrecFreq1(Double_t value) { fMuPrecFreq1 = value; } //!< sets Mu hyperfine coupling (MHz)
virtual void SetMuPrecFreq2(Double_t value) { fMuPrecFreq2 = value; } //!< sets Mu hyperfine coupling (MHz)
virtual void SetMuPrecFreq12(Double_t value) { fMuPrecFreq12 = value; } //!< sets Mu transition frequency (MHz)
virtual void SetMuPrecFreq34(Double_t value) { fMuPrecFreq34 = value; } //!< sets Mu transition frequency (MHz)
virtual void SetMuPrecFreq23(Double_t value) { fMuPrecFreq23 = value; } //!< sets Mu transition frequency (MHz)
virtual void SetMuPrecFreq14(Double_t value) { fMuPrecFreq14 = value; } //!< sets Mu transition frequency (MHz)
virtual void SetCaptureRate(Double_t value){ fCaptureRate = value; } //!< sets Mu+ electron capture rate (MHz)
virtual void SetIonizationRate(Double_t value){ fIonizationRate = value; } //!< sets Mu0 ionization rate (MHz)
virtual void SetDecayAsymmetry(Double_t value){ fAsymmetry = value; } //!< muon decay asymmetry
@ -71,8 +73,10 @@ class PSimulateMuTransition : public TObject
TRandom2 *fRandom;
Double_t fBfield; //!< magnetic field (T)
Double_t fMuPrecFreq1; //!< Mu precession frequency of state 1 (MHz)
Double_t fMuPrecFreq2; //!< Mu precession frequency of state 2 (MHz)
Double_t fMuPrecFreq12; //!< Mu transition frequency 12 (MHz)
Double_t fMuPrecFreq34; //!< Mu transition frequency 34 (MHz)
Double_t fMuPrecFreq23; //!< Mu transition frequency 23 (MHz)
Double_t fMuPrecFreq14; //!< Mu transition frequency 14 (MHz)
Double_t fCaptureRate; //!< Mu+ electron capture rate (MHz)
Double_t fIonizationRate; //!< Mu0 ionization rate (MHz)
Double_t fInitialPhase; //!< initial muon spin phase

35
src/tests/MuTransition/runMuSimulation.C
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@ -43,14 +43,15 @@ void runMuSimulation()
decayAnaModule = histosFolder->AddFolder("DecayAnaModule", "muSR decay histograms");
// feed run info header
UInt_t runNo = 9102;
UInt_t runNo = 9702;
TString tstr;
runInfo = gROOT->GetRootFolder()->AddFolder("RunInfo", "LEM RunInfo");
gROOT->GetListOfBrowsables()->Add(runInfo, "RunInfo");
header = new TLemRunHeader();
tstr = TString("0");
tstr += runNo;
tstr += TString(" - test");
tstr += TString("Ge, Mu-frac 1.0, Mu12 737MHz (0.44), Mu34 -1622MHz(0.44), T=220K/EA=170meV, Cap.(200K) 0.0MHz, 100mT");
header->SetRunTitle(tstr.Data());
header->SetLemSetup("trivial");
header->SetRunNumber(runNo);
@ -60,7 +61,7 @@ void runMuSimulation()
header->SetSampleHV(0.0, 0.01);
header->SetImpEnergy(31.8);
header->SetSampleTemperature(0.2, 0.001);
header->SetSampleBField(-1.0, 0.1);
header->SetSampleBField(100.0, 0.1);
header->SetTimeResolution(1.);
header->SetNChannels(12001);
header->SetNHist(2);
@ -86,15 +87,25 @@ void runMuSimulation()
return;
}
//prepare to run simulation
simulateMuTransition->SetMuPrecFreq1(41.); // MHz
simulateMuTransition->SetMuPrecFreq2(-35.); // MHz
simulateMuTransition->SetMuFraction(0.5); // initial Mu fraction
simulateMuTransition->SetMuFractionState1(0.42); // 100% of Mu in state 1
simulateMuTransition->SetMuFractionState2(0.32); // 0% of Mu in state 2
simulateMuTransition->SetBfield(0.01); // Tesla
simulateMuTransition->SetCaptureRate(1.5); // MHz
simulateMuTransition->SetIonizationRate(250.); // MHz
//prepare to run simulation; here: isotropic Mu in Germanium
Double_t ionRate; //assume Arrhenius behaviour ionRate = preFac*exp(-EA/kT)
Double_t capRate; //assume that capture rate varies as sqrt(T), capRate = sigma*v*p , v ~ sqrt(T)
Double_t EA, T; //activation energy (meV) and temperature (K)
EA = 170.;
T = 220.;
ionRate = 2.9e7 * exp(-EA/(0.08625*T)); // Ge: 2.9*10^7MHz "attempt" frequency; 1K = 0.08625 meV
capRate = 0.00001*sqrt(T/200.);
simulateMuTransition->SetMuPrecFreq12(737.3); // MHz
simulateMuTransition->SetMuPrecFreq34(-1622.2); // MHz
simulateMuTransition->SetMuPrecFreq23(2051.6); // MHz
simulateMuTransition->SetMuPrecFreq14(4111.2); // MHz
simulateMuTransition->SetMuFraction(1.0); // initial Mu fraction
simulateMuTransition->SetMuFractionState1(0.88); // Mu in states 12, 34
simulateMuTransition->SetMuFractionState2(0.12); // Mu in states 23, 14
simulateMuTransition->SetBfield(0.1); // Tesla
simulateMuTransition->SetCaptureRate(capRate); // MHz
simulateMuTransition->SetIonizationRate(ionRate); // MHz
simulateMuTransition->SetNmuons(1e7);
simulateMuTransition->SetDecayAsymmetry(0.27);
simulateMuTransition->SetDebugFlag(kFALSE); // to print time and phase during charge-changing cycle