Closed SimonHeybrock closed 7 months ago
Is the time at the sample $t_s = L_1/v$ where $v = (L_1 + L2) / t{d}$ where $t_d$ is the time of flight?
Almost, this is about the absolute time at the sample, so $t_0 + t_s$ in your notation. It is probably easiest to calculate backwards from the detector position (i.e., we do not require $L_1$).
Okay I see, so we should compute the absolute time like $t_{abs,\ s} = t_0 + t_s = t_0 + t_d - L_2 / v$?
Okay I see, so we should compute the absolute time like tabs, s=t0+ts=t0+td−L2/v?
Yes, and we might go via wavelength, since $v$ is generally not required, but wavelength is computed in many cases already.
Where do we get $t_0$ (the time when the neutron passes the point where L=0)?
We must assume we have it, it is generally called pulse_time
in our workflows, though that is subject to change.
This is required for event data filtering for fast sample environment parameters, e.g., in ESSsans.
Should this be added to the regular coord transform graphs that ScippNeutron provides?