musrfit/src/external/Nonlocal/PNL_PippardFitter.cpp

465 lines
15 KiB
C++

/***************************************************************************
PNL_PippardFitter.cpp
Author: Andreas Suter
e-mail: andreas.suter@psi.ch
***************************************************************************/
/***************************************************************************
* Copyright (C) 2009-2021 by Andreas Suter *
* andreas.suter@psi.ch *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#include <cassert>
#include <cmath>
#include <iostream>
#include <TSAXParser.h>
#include <TMath.h>
#include "PNL_PippardFitter.h"
#define GAMMA_MU 0.0851615503527
#define DEGREE2RAD 0.0174532925199
ClassImp(PNL_PippardFitterGlobal)
//--------------------------------------------------------------------------
// Constructor
//--------------------------------------------------------------------------
/**
*
*/
PNL_PippardFitterGlobal::PNL_PippardFitterGlobal()
{
// read XML startup file
char startup_path_name[128];
TSAXParser *saxParser = new TSAXParser();
PNL_StartupHandler *fStartupHandler = new PNL_StartupHandler();
strcpy(startup_path_name, fStartupHandler->GetStartupFilePath().Data());
saxParser->ConnectToHandler("PNL_StartupHandler", fStartupHandler);
//Int_t status = saxParser->ParseFile(startup_path_name);
// parsing the file as above seems to lead to problems in certain environments;
// use the parseXmlFile function instead (see PUserFcnBase.cpp for the definition)
Int_t status = parseXmlFile(saxParser, startup_path_name);
// check for parse errors
if (status) { // error
std::cout << std::endl << ">> PNL_PippardFitterGlobal::PNL_PippardFitterGlobal: **WARNING** Reading/parsing nonlocal_startup.xml failed.";
std::cout << std::endl;
fValid = false;
}
// clean up
if (saxParser) {
delete saxParser;
saxParser = 0;
}
// check if everything went fine with the startup handler
if (!fStartupHandler->IsValid()) {
std::cout << std::endl << ">> PNL_PippardFitterGlobal::PNL_PippardFitterGlobal **PANIC ERROR**";
std::cout << std::endl << ">> startup handler too unhappy. Will terminate unfriendly, sorry.";
std::cout << std::endl;
fValid = false;
}
fFourierPoints = fStartupHandler->GetFourierPoints();
// load all the TRIM.SP rge-files
fRgeHandler = new PRgeHandler("./nonlocal_startup.xml");
if (!fRgeHandler->IsValid()) {
std::cout << std::endl << ">> PNL_PippardFitterGlobal::PNL_PippardFitterGlobal **PANIC ERROR**";
std::cout << std::endl << ">> rge data handler too unhappy. Will terminate unfriendly, sorry.";
std::cout << std::endl;
fValid = false;
}
fPlanPresent = false;
fFieldq = 0;
fFieldB = 0;
fShift = 0;
f_nn = 4.0;
f_dx = 0.02;
}
//--------------------------------------------------------------------------
// Destructor
//--------------------------------------------------------------------------
/**
*
*/
PNL_PippardFitterGlobal::~PNL_PippardFitterGlobal()
{
fPreviousParam.clear();
if (fPlanPresent) {
fftw_destroy_plan(fPlan);
}
if (fFieldq) {
fftw_free(fFieldq);
fFieldq = 0;
}
if (fFieldB) {
fftw_free(fFieldq);
fFieldB = 0;
}
if (fRgeHandler) {
delete fRgeHandler;
fRgeHandler = 0;
}
if (fStartupHandler) {
delete fStartupHandler;
fStartupHandler = 0;
}
}
//--------------------------------------------------------------------------
// CalculateField (public)
//--------------------------------------------------------------------------
/**
*
*/
void PNL_PippardFitterGlobal::CalculateField(const std::vector<Double_t> &param) const
{
// param: [0] energy, [1] temp, [2] thickness, [3] meanFreePath, [4] xi0, [5] lambdaL, [6] Bext, [7] phase, [8] dead-layer
// check that param are new and hence a calculation is needed (except the energy and phase, which is not needed here)
Bool_t newParams = false;
if (fPreviousParam.size() == 0) {
for (UInt_t i=0; i<param.size(); i++)
fPreviousParam.push_back(param[i]);
newParams = true;
} else {
assert(param.size() == fPreviousParam.size());
for (UInt_t i=0; i<param.size(); i++) {
if ((i == 0) || (i >= 6)) // for energy, Bext, phase, and dead-layer, nothing to be done here
continue;
if (param[i] != fPreviousParam[i]) {
newParams = true;
break;
}
}
}
if (!newParams)
return;
// keep parameters
for (UInt_t i=0; i<param.size(); i++)
fPreviousParam[i] = param[i];
f_dz = XiP_T(param[4], param[3], param[1])*TMath::TwoPi()/fFourierPoints/f_dx; // see lab-book p.137, used for specular reflection boundary conditions (default)
// check if it is necessary to allocate memory
if (fFieldq == 0) {
fFieldq = (fftw_complex *) fftw_malloc(sizeof(fftw_complex) * fFourierPoints);
if (fFieldq == 0) {
std::cout << std::endl << "PPippard::CalculateField(): **ERROR** couldn't allocate memory for fFieldq";
std::cout << std::endl;
return;
}
}
if (fFieldB == 0) {
fFieldB = (fftw_complex *) fftw_malloc(sizeof(fftw_complex) * fFourierPoints);
if (fFieldB == 0) {
std::cout << std::endl << "PPippard::CalculateField(): **ERROR** couldn't allocate memory for fFieldB";
std::cout << std::endl;
return;
}
}
// calculate the prefactor of the reduced kernel
Double_t xiP = XiP_T(param[4], param[3], param[1]);
Double_t preFactor = pow(xiP/(LambdaL_T(param[5], param[1])),2.0)*xiP/param[4];
// calculate the fFieldq vector, which is x/(x^2 + alpha k(x)), with alpha = xiP(T)^3/(lambdaL(T)^2 xiP(0)), and
// k(x) = 3/2 [(1+x^2) arctan(x) - x]/x^3, see lab-book p.137
Double_t x;
fFieldq[0][0] = 0.0;
fFieldq[0][1] = 0.0;
for (Int_t i=1; i<fFourierPoints; i++) {
x = i * f_dx;
fFieldq[i][0] = x/(pow(x,2.0)+preFactor*(1.5*((1.0+pow(x,2.0))*atan(x)-x)/pow(x,3.0)));
fFieldq[i][1] = 0.0;
}
// Fourier transform
if (!fPlanPresent) {
fPlan = fftw_plan_dft_1d(fFourierPoints, fFieldq, fFieldB, FFTW_FORWARD, FFTW_ESTIMATE);
fPlanPresent = true;
}
fftw_execute(fPlan);
// normalize fFieldB
Double_t norm = 0.0;
fShift=0;
for (Int_t i=0; i<fFourierPoints/2; i++) {
if (fabs(fFieldB[i][1]) > fabs(norm)) {
norm = fFieldB[i][1];
fShift = i;
}
}
for (Int_t i=0; i<fFourierPoints; i++) {
fFieldB[i][1] /= norm;
}
if (param[2] < fFourierPoints/2.0*f_dz) {
// B(z) = b(z)+b(D-z)/(1+b(D)) is the B(z) result
Int_t idx = (Int_t)(param[2]/f_dz);
norm = 1.0 + fFieldB[idx+fShift][1];
for (Int_t i=0; i<fFourierPoints; i++) {
fFieldB[i][0] = 0.0;
}
for (Int_t i=fShift; i<idx+fShift; i++) {
fFieldB[i][0] = (fFieldB[i][1] + fFieldB[idx-i+2*fShift][1])/norm;
}
for (Int_t i=0; i<fFourierPoints; i++) {
fFieldB[i][1] = fFieldB[i][0];
}
}
}
//--------------------------------------------------------------------------
// GetMagneticField
//--------------------------------------------------------------------------
/**
*
*/
Double_t PNL_PippardFitterGlobal::GetMagneticField(const Double_t z) const
{
Double_t result = -1.0;
if (fFieldB == 0)
return -1.0;
if (z <= 0.0)
return 1.0;
if (z > f_dz*fFourierPoints/2.0)
return 0.0;
Int_t bin = (Int_t)(z/f_dz);
result = fFieldB[bin+fShift][1];
return result;
}
//--------------------------------------------------------------------------
// DeltaBCS
//--------------------------------------------------------------------------
/**
*
*/
Double_t PNL_PippardFitterGlobal::DeltaBCS(const Double_t t) const
{
Double_t result = 0.0;
// reduced temperature table
Double_t tt[] = {1, 0.98, 0.96, 0.94, 0.92, 0.9, 0.88, 0.86, 0.84, 0.82,
0.8, 0.78, 0.76, 0.74, 0.72, 0.7, 0.68, 0.66, 0.64, 0.62,
0.6, 0.58, 0.56, 0.54, 0.52, 0.5, 0.48, 0.46, 0.44, 0.42,
0.4, 0.38, 0.36, 0.34, 0.32, 0.3, 0.28, 0.26, 0.24, 0.22,
0.2, 0.18, 0.16, 0.14};
// gap table from Muehlschlegel
Double_t ee[] = {0, 0.2436, 0.3416, 0.4148, 0.4749, 0.5263, 0.5715, 0.6117,
0.648, 0.681, 0.711, 0.7386, 0.764, 0.7874, 0.8089, 0.8288,
0.8471, 0.864, 0.8796, 0.8939, 0.907, 0.919, 0.9299, 0.9399,
0.9488, 0.9569, 0.9641, 0.9704, 0.976, 0.9809, 0.985, 0.9885,
0.9915, 0.9938, 0.9957, 0.9971, 0.9982, 0.9989, 0.9994, 0.9997,
0.9999, 1, 1, 1, 1};
if (t>1.0)
result = 0.0;
else if (t<0.14)
result = 1.0;
else {
// find correct bin for t
UInt_t i=0;
for (i=0; i<sizeof(tt); i++) {
if (tt[i]<=t) break;
}
// interpolate linear between 2 bins
result = ee[i]-(tt[i]-t)*(ee[i]-ee[i-1])/(tt[i]-tt[i-1]);
}
return result;
}
//--------------------------------------------------------------------------
// LambdaL_T
//--------------------------------------------------------------------------
/**
*
*/
Double_t PNL_PippardFitterGlobal::LambdaL_T(const Double_t lambdaL, const Double_t t) const
{
return lambdaL/sqrt(1.0-pow(t, f_nn));
}
//--------------------------------------------------------------------------
// XiP_T
//--------------------------------------------------------------------------
/**
* <p> Approximated xi_P(T). The main approximation is that (lamdaL(T)/lambdaL(0))^2 = 1/(1-t^2). This way
* xi_P(T) is close the the BCS xi_BCS(T).
*/
Double_t PNL_PippardFitterGlobal::XiP_T(const Double_t xi0, const Double_t meanFreePath, Double_t t) const
{
if (t>0.96)
t=0.96;
Double_t J0T = DeltaBCS(t)/(1.0-pow(t,2.0)) * tanh(0.881925 * DeltaBCS(t) / t);
return xi0*meanFreePath/(meanFreePath*J0T+xi0);
}
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ClassImp(PNL_PippardFitter)
//--------------------------------------------------------------------------
// Destructor
//--------------------------------------------------------------------------
/**
*
*/
PNL_PippardFitter::~PNL_PippardFitter()
{
if ((fPippardFitterGlobal != 0) && fInvokedGlobal) {
delete fPippardFitterGlobal;
fPippardFitterGlobal = 0;
}
}
//--------------------------------------------------------------------------
// SetGlobalPart (public)
//--------------------------------------------------------------------------
/**
* <p>
*
* <b>return:</b>
*
* \param globalPart
* \param idx
*/
void PNL_PippardFitter::SetGlobalPart(std::vector<void*> &globalPart, UInt_t idx)
{
fIdxGlobal = static_cast<Int_t>(idx);
if ((Int_t)globalPart.size() <= fIdxGlobal) {
fPippardFitterGlobal = new PNL_PippardFitterGlobal();
if (fPippardFitterGlobal == nullptr) {
fValid = false;
std::cerr << std::endl << ">> PNL_PippardFitter::SetGlobalPart(): **ERROR** Couldn't invoke global user function object, sorry ..." << std::endl;
} else if (!fPippardFitterGlobal->IsValid()) {
fValid = false;
std::cerr << std::endl << ">> PNL_PippardFitter::SetGlobalPart(): **ERROR** initialization of global user function object failed, sorry ..." << std::endl;
} else {
fValid = true;
fInvokedGlobal = true;
globalPart.resize(fIdxGlobal+1);
globalPart[fIdxGlobal] = dynamic_cast<PNL_PippardFitterGlobal*>(fPippardFitterGlobal);
}
} else {
fValid = true;
fPippardFitterGlobal = (PNL_PippardFitterGlobal*)globalPart[fIdxGlobal];
}
}
//--------------------------------------------------------------------------
// GlobalPartIsValid (public)
//--------------------------------------------------------------------------
/**
* <p>
*
* <b>return:</b>
*/
Bool_t PNL_PippardFitter::GlobalPartIsValid() const
{
return (fValid && fPippardFitterGlobal->IsValid());
}
//--------------------------------------------------------------------------
// operator()
//--------------------------------------------------------------------------
/**
*
*/
Double_t PNL_PippardFitter::operator()(Double_t t, const std::vector<Double_t> &param) const
{
// param: [0] energy, [1] temp, [2] thickness, [3] meanFreePath, [4] xi0, [5] lambdaL, [6] Bext, [7] phase, [8] dead-layer
// optionally [9] nn, where nn is the exponent in lambda = lambda_L / sqrt(1-t^nn). Default is nn=4.
assert((param.size() == 9) || (param.size() == 10));
if (param.size() == 10) // nn given, hence set it
fPippardFitterGlobal->SetTempExponent(param[9]);
// for negative time return polarization == 1
if (t <= 0.0)
return 1.0;
// calculate field if parameter have changed
fPippardFitterGlobal->CalculateField(param);
Int_t energyIndex = fPippardFitterGlobal->GetEnergyIndex(param[0]);
if (energyIndex == -1) { // energy not found
std::cerr << std::endl << ">> PNL_PippardFitter::operator() energy " << param[0] << " not found. Will terminate." << std::endl;
assert(0);
}
// calcualte polarization
Bool_t done = false;
Double_t pol = 0.0, dPol = 0.0;
Double_t z=0.0;
Int_t terminate = 0;
Double_t dz = 1.0;
do {
if (z < param[8]) { // z < dead-layer
dPol = fPippardFitterGlobal->GetMuonStoppingDensity(energyIndex, z) * cos(GAMMA_MU * param[6] * t + param[7] * DEGREE2RAD);
} else {
dPol = fPippardFitterGlobal->GetMuonStoppingDensity(energyIndex, z) * cos(GAMMA_MU * param[6] * fPippardFitterGlobal->GetMagneticField(z-param[8]) * t + param[7] * DEGREE2RAD);
}
z += dz;
pol += dPol;
// change in polarization is very small hence start termination counting
if (fabs(dPol) < 1.0e-9) {
terminate++;
} else {
terminate = 0;
}
if (terminate > 10) // polarization died out hence one can stop
done = true;
} while (!done);
return pol*dz;
}