Optimized signal deduction procedure for the MIEZE spectroscopy technique

Area of Science:

• Neutron scattering
• Spectroscopy
• Data analysis

Background:

• Sinusoidally modulated event rates are common in neutron spin-echo spectroscopy.
• Current analysis methods can be computationally intensive and lead to contrast reduction.
• The resonant neutron spin-echo spectrometer (RESEDA) at FRM-II faces data acquisition bottlenecks.

Purpose of the Study:

• To develop a novel method for determining phase and amplitude of modulated event rates.
• To improve data acquisition speed and time resolution at the RESEDA spectrometer.
• To compare the new method with established time series fitting procedures.

Main Methods:

• A reconstruction algorithm is presented for parameter estimation without intensive fitting.
• The method utilizes data binned into four bins per oscillation.
• Comparison with fitting procedures using four and 16 time bins per oscillation.

Main Results:

• The reconstruction method increases potential time resolution by a factor of four.
• It avoids calculation-intensive fitting and contrast reduction due to averaging.
• The reconstruction is unbiased, asymptotic, and efficient for phase estimation; contrast estimation shows a ~10% increase in error bars compared to 16-bin fitting.

Conclusions:

• The developed reconstruction method offers a significant improvement in data analysis efficiency for neutron spin-echo experiments.
• It provides a faster and potentially more accurate alternative to traditional fitting methods.
• Heuristic, analytical equations are provided for error estimation of phase and contrast.