Finding samples

Now its time to expose your sample to x-ray photons. Prior to this, check from synoptic if we have beam on the slit, and all the valves are open. If the sample rod is still in the UC, make sure to open the valve between Q-chamber and UC.

We first start with a 2D spatial map of the sample (a_mp1_x vs. a_mp1_y), after setting a_mp1_yaw at normal incidence. From this point on, you are going to use the control and acquisition software named ‘Scangui’. Here is how we do it:

Mesh scan

This is a 2D mapping of your sample using appropriate beamline energy. In the first attempt, the beamline energy does not need to be exactly the resonance energy, rather, any energy close to the resonant energy will work to get the contrast. You need to open these two softwares: Scangui and Sampletracker

After loading the sample down to the main chamber (we call it Q-chamber), you first begin with the mesh scan. This is how you can setup the mesh scan in Scangui:

go to ‘MacroExecutor’ or ‘Sequencer’ tab –> find ‘mesh’ macro from the ‘Macro’ dropdown list –> add it –> at the bottom, select the values ‘a_mp1_x’ and ‘a_mp1_y’ under parameters ‘motor1’ and ‘motor2’, respectively –> give start and final motors positions, nr_interval (number of steps), and integ_time. Set bidirectional to ‘true’ or ‘false’.

Linescan

With the Scangui, you can along x or y while reading an absorption intensity

  1. Start the Scanguiand the quickgui

  2. From the quickgui: Write down current manipulator positions: a_mp1_x, a_mp1_y, a_mp1_z, and a_mp1_yaw

  3. In the quickgui, choose an appropriate beamline_energy for getting contrast when you are on the sample

  4. In the Scangui, select the measurement group “NEXAFS” (see details on how to change measurement group in the entry about the Scangui)

  5. In the Scangui, go to basic executor select a_mp1_x or a_mp1_y and scan around your starting guess

  6. In the Scangui, plot a_mp1_x towards the appropriate alba elektrometer signal