BornAgain  1.18.0
Simulate and fit neutron and x-ray scattering at grazing incidence
DetectionProperties.cpp
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1 // ************************************************************************** //
2 //
3 // BornAgain: simulate and fit scattering at grazing incidence
4 //
5 //! @file Device/Detector/DetectionProperties.cpp
6 //! @brief Implements class DetectionProperties.
7 //!
8 //! @homepage http://www.bornagainproject.org
9 //! @license GNU General Public License v3 or higher (see COPYING)
10 //! @copyright Forschungszentrum Jülich GmbH 2018
11 //! @authors Scientific Computing Group at MLZ (see CITATION, AUTHORS)
12 //
13 // ************************************************************************** //
14 
16 #include "Base/Types/Complex.h"
17 #include "Base/Types/Exceptions.h"
19 
21  double total_transmission)
22  : m_direction(direction), m_efficiency(efficiency), m_total_transmission(total_transmission)
23 {
24  setName("Analyzer");
25  registerVector("Direction", &m_direction, "");
26  registerParameter("Efficiency", &m_efficiency);
28 }
29 
31 
33  : DetectionProperties(other.m_direction, other.m_efficiency, other.m_total_transmission)
34 {
35 }
36 
37 void DetectionProperties::setAnalyzerProperties(const kvector_t direction, double efficiency,
38  double total_transmission)
39 {
40  if (!checkAnalyzerProperties(direction, efficiency, total_transmission))
41  throw Exceptions::ClassInitializationException("IDetector2D::setAnalyzerProperties: the "
42  "given properties are not physical");
43  if (efficiency == 0.0 || total_transmission == 0.0 || direction.mag() == 0.0) {
45  m_efficiency = 0.0;
46  } else {
47  m_direction = direction.unit();
48  m_efficiency = efficiency;
49  }
50  m_total_transmission = total_transmission;
51 }
52 
53 Eigen::Matrix2cd DetectionProperties::analyzerOperator() const
54 {
55  if (m_direction.mag() == 0.0 || m_efficiency == 0.0)
56  return m_total_transmission * Eigen::Matrix2cd::Identity();
57  Eigen::Matrix2cd result;
58  double x = m_direction.x() / m_direction.mag();
59  double y = m_direction.y() / m_direction.mag();
60  double z = m_direction.z() / m_direction.mag();
61  double sum = m_total_transmission * 2.0;
62  double diff = m_total_transmission * m_efficiency * 2.0;
63  complex_t im(0.0, 1.0);
64  result(0, 0) = (sum + diff * z) / 2.0;
65  result(0, 1) = diff * (x - im * y) / 2.0;
66  result(1, 0) = diff * (x + im * y) / 2.0;
67  result(1, 1) = (sum - diff * z) / 2.0;
68  return result;
69 }
70 
72 {
73  return m_direction;
74 }
75 
77 {
78  return m_efficiency;
79 }
80 
82 {
83  return m_total_transmission;
84 }
85 
86 bool DetectionProperties::checkAnalyzerProperties(const kvector_t direction, double efficiency,
87  double total_transmission) const
88 {
89  if (direction.mag() == 0.0)
90  return false;
91  double aplus = total_transmission * (1.0 + efficiency);
92  double amin = total_transmission * (1.0 - efficiency);
93  if (aplus < 0.0 || aplus > 1.0)
94  return false;
95  if (amin < 0.0 || amin > 1.0)
96  return false;
97  return true;
98 }
Defines complex_t, and a few elementary functions.
std::complex< double > complex_t
Definition: Complex.h:20
Defines class DetectionProperties.
Defines many exception classes in namespace Exceptionss.
Defines class RealParameter.
BasicVector3D< T > unit() const
Returns unit vector in direction of this. Throws for null vector.
double mag() const
Returns magnitude of the vector.
T z() const
Returns z-component in cartesian coordinate system.
Definition: BasicVector3D.h:68
T y() const
Returns y-component in cartesian coordinate system.
Definition: BasicVector3D.h:66
T x() const
Returns x-component in cartesian coordinate system.
Definition: BasicVector3D.h:64
Detector properties (efficiency, transmission).
double m_efficiency
efficiency of polarization analysis
double m_total_transmission
total transmission of polarization analysis
double analyzerEfficiency() const
will always return positive value
void setAnalyzerProperties(const kvector_t direction, double efficiency, double total_transmission)
Sets the polarization analyzer characteristics of the detector.
double analyzerTotalTransmission() const
bool checkAnalyzerProperties(const kvector_t direction, double efficiency, double total_transmission) const
Verify if the given analyzer properties are physical.
kvector_t m_direction
direction of polarization analysis
kvector_t analyzerDirection() const
Retrieve the analyzer characteristics.
Eigen::Matrix2cd analyzerOperator() const
Return the polarization density matrix (in spin basis along z-axis)
RealParameter & registerParameter(const std::string &name, double *parpointer)
void setName(const std::string &name)
void registerVector(const std::string &base_name, kvector_t *p_vec, const std::string &units="nm")
RealParameter & setNonnegative()