void BbyDetectorBankFactory::createAndAssign(size_t startIndex,
const Kernel::V3D &pos,
const Kernel::Quat &rot) const {
// create a RectangularDetector which represents a rectangular array of pixels
Geometry::RectangularDetector *bank = new Geometry::RectangularDetector(
"bank",
m_instrument.get()); // Bank gets registered with instrument component.
// instrument acts as sink and manages lifetime.
bank->initialize(m_pixelShape,
// x
static_cast<int>(m_xPixelCount), 0, m_pixelWidth,
// y
static_cast<int>(m_yPixelCount), 0, m_pixelHeight,
// indices
static_cast<int>(startIndex), true,
static_cast<int>(m_yPixelCount));
for (size_t x = 0; x < m_xPixelCount; ++x)
for (size_t y = 0; y < m_yPixelCount; ++y)
m_instrument->markAsDetector(
bank->getAtXY(static_cast<int>(x), static_cast<int>(y)).get());
Kernel::V3D center(m_center);
rot.rotate(center);
bank->rotate(rot);
bank->translate(pos - center);
}
/**
* This function calculates the exponential contribution to the He3 tube
* efficiency.
* @param spectraIndex :: the current index to calculate
* @param idet :: the current detector pointer
* @throw out_of_range if twice tube thickness is greater than tube diameter
* @return the exponential contribution for the given detector
*/
double He3TubeEfficiency::calculateExponential(
std::size_t spectraIndex,
boost::shared_ptr<const Geometry::IDetector> idet) {
// Get the parameters for the current associated tube
double pressure =
this->getParameter("TubePressure", spectraIndex, "tube_pressure", idet);
double tubethickness =
this->getParameter("TubeThickness", spectraIndex, "tube_thickness", idet);
double temperature = this->getParameter("TubeTemperature", spectraIndex,
"tube_temperature", idet);
double detRadius(0.0);
Kernel::V3D detAxis;
this->getDetectorGeometry(idet, detRadius, detAxis);
double detDiameter = 2.0 * detRadius;
double twiceTubeThickness = 2.0 * tubethickness;
// now get the sin of the angle, it's the magnitude of the cross product of
// unit vector along the detector tube axis and a unit vector directed from
// the sample to the detector center
Kernel::V3D vectorFromSample = idet->getPos() - this->samplePos;
vectorFromSample.normalize();
Kernel::Quat rot = idet->getRotation();
// rotate the original cylinder object axis to get the detector axis in the
// actual instrument
rot.rotate(detAxis);
detAxis.normalize();
// Scalar product is quicker than cross product
double cosTheta = detAxis.scalar_prod(vectorFromSample);
double sinTheta = std::sqrt(1.0 - cosTheta * cosTheta);
const double straight_path = detDiameter - twiceTubeThickness;
if (std::fabs(straight_path - 0.0) < TOL) {
throw std::out_of_range("Twice tube thickness cannot be greater than "
"or equal to the tube diameter");
}
const double pathlength = straight_path / sinTheta;
return EXP_SCALAR_CONST * (pressure / temperature) * pathlength;
}