scippneutron.tof.unwrap.time_of_flight_origin_from_chopper#
- scippneutron.tof.unwrap.time_of_flight_origin_from_chopper(source_chopper)#
Compute the time-of-flight origin from a source chopper.
This is a naive approach for defining the time of flight. We are not sure this is going to be used in practice. An possible alternative might be to calibrate the time-of-flight using a sample with a known Bragg edge. This is not implemented currently.
A chopper is used to define (1) the “source” location and (2) the time-of-flight time origin. The time-of-flight is then the time difference between the time of arrival of the neutron at the detector, and the time of arrival of the neutron at the chopper. L1 needs to be redefined to be the distance between the chopper and the sample.
If there is no pulse-shaping chopper, then the source-pulse begin and end time should be set as the source_time_open and source_time_close, respectively.
For WFM, the source_time_open and source_time_close will be different for each subframe. In this case, all input parameters should be given as variables with subframe as dimension.
- Parameters:
source_chopper (
tof.unwrap.SourceChopper(scippneutron.tof.chopper_cascade.Chopper)) – Chopper defining the source location and time-of-flight time origin (as the center of the slit opening). The chopper distance is assumed to be the distance from the source position.- Return type: