IntegratePeaksCWSD v1¶

Simple Peak Integration¶

Integration is performed by summing the signal from all MDEvents that are not masked. The integrated value will be normalized by the monitor counts.

The assumption is to load an experiment point (Pt) and convert to MDEventWorkspace in Q-space. This Pt, i.e., workspace, contains at most one peak. Algorithm FindPeaksMD is able to find a peak in the MDEventWorkspace and output to a PeaksWorkspace. A UB matrix is set to this PeaksWorkspace as an option.

The pseduo-code of this algorithm is:

1. Go over all the MDEvents;
2. For Pt. (aka, run number) i, its integrated intensity \(I_{i}\) is calculated as \(I_{i} = \sum_{d=0}^{256\times 256}\frac{s_d}{m}\), where \(s_i\) is the signal of detector i, and m is the monitor counts;

Here is how this peak integration algorithm is applied to GUI

1. Find out all the run numbers by experiment number and scan number;
2. Execute FindPeaksMD() on all runs (i.e., Pts);
3. Calculate peak center by \(\vec{p} = \frac{1}{\sum_i C_i} \sum_i C_i * \vec{p}_i\), where \(\vec{p}\) is the center of the peak, \(C_i\) is the bin count of run i;
4. Execute IntegratePeaksCWSD() to integrate peak for each run (or Pt.) regardless whether a peak is found;
5. Loop all the Pt. and sum the intensity as \(I = \sum_i I_i\), where :math:

Calculation of integrated background¶

There are two approaches that are proposed to estimate integrated background.

1. Simple background removal (3D to 2D)
   • Assuming that \(r_p\) and \(r_b\) are defined for the radius of peak and background respectively.
   • Calculate \(I_p\) by integrating the signals within \(r_p\);
   • Calculate \(I_pb\) by integrating the signals within \(r_b\);
   • Then integrated background \(I_b = I_pb - I_p\);
2. Rock scan

Outputs¶

Here are some values to be output.

• \(I_{scan} \cdot sin(2\theta)\) for each scan with \(2\theta\) fixed, where \(2\theta\) is to the center of the detector.