scippneutron.conversion.tof.time_at_sample_from_wavelength#

scippneutron.conversion.tof.time_at_sample_from_wavelength(*, toa, L2, wavelength)[source]#

Compute the absolute time when the neutron passed through the sample.

The result is

\[t_{sample} = t_{\mathsf{arrival}} - L_2 / v\]

where \(t_{\mathsf{arrival}}\) is the absolute time when the neutron arrives at the detector, \(L_2\) is the path length from sample to detector, and

\[v = \frac{h}{m_n \lambda}\]

is the estimated velocity of the neutron over its path from sample to detector. Here, \(\lambda\) is the wavelength of the neutron, \(h\) is the Planck constant, and \(m_n\) is the neutron mass.

Parameters:

  • toa (Variable) – the absolute time when the neutron arrives at the detector

  • L2 (Variable) – path length from sample to detector

  • wavelength (Variable) – wavelength of the neutron (at the detector). Assuming this did not change during the neutrons travel from sample to detector this can be used to compute the velocity the neutron had between the sample and the detector.

Returns:

Variable – \(t_{sample}\)