USAXS Imaging Operations

[prjemian]

The fundamental idea of USAXS imaging data acquisition is remarkably
simple. Basically, this is what we do.

1. We collect a USAXS pattern which gives us an idea about the
   scattering power of the sample.
2. We decide a few q values where we want the images to be acquired.
3. At each q, we decide the number of filters that is required and the
   image acquisition time, and acquire 4 images. Immediately after
   tuning of the instrument, we acquire
   1. USAXS image (sample in the beam, with filter, beam on).
   2. Optics (sample not in the beam, with filter, beam on).
   3. Dark field (beam off).
   4. Flat field image (sample not in the beam, q = 0, with filter,
      beam on, image acquisition time may need to be shortened to
      prevent saturation).
4. For tomography, the only difference is that at a given q, we acquire
   the data at a range of rotational angles (0° to 181°) with angular
   step between 0.5° and 2°. We do not have to acquire Optics, Dark
   field, and Flat field images (3.b, 3.c, and 3.d) for every USAXS
   image. Instead, one set per preUSAXStune is considered adequate.
   (For large q, the image acquisition time is long. Hence, we need to
   separate the tomographic data series into a few segments with
   preUSAXStune in-between).

[prjemian]

See these issues:

Step 1.

• done

Step 2.

• manual

Step 3.

• need use_mode_imaging #85 need use_mode_imaging (and change instrument mode #36 change instrument mode)
• USAXS imaging sequence (plan) #223 USAXS imaging sequence (plan)

Step 4.

• USAXS tomo (plan) #224 USAXS tomo (plan)

[prjemian]

Now that specific issues are created for each step (remaining to be implemented), closing here.