You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 2 Next »

Step-by-step guide

Femtosecond timing in sample chamber 1 (SC1) at CXI.

  1. Install a fast diode and mirror (roughly at 45 degrees with respect to the beam) on the SC1 sample_x stage
  2. Roughly align the fast diode and mirror using the reference laser at the time tool (-4 mm in position but this will soon be changed to 0 mm.   If the "out" position is 92 mm, then -4 mm, if 96 mm, then 0 mm).
  3. Insert a nozzle rod with both a clear YAG and a frosted YAG. 
    1. At CXI, the clear YAGs are typically thinner, around 20 um, whereas the frosted YAGs are thicker, around 50 um
  4. Align the laser with crosshairs on the inline cameras that represent the location of the X-ray beam
    1. In the image below, the bright spot is the laser spot at the interaction point (IP) visualized using a frosted YAG.  The frosted YAG is on the upper half of the image.  There is a small gap followed by the bottom 1/4 of the image having a clear YAG.
    1. The laser needs to be repointed using Pico X (CXI:LAS:PIC:03) and Pico Y (CXI:LAS:PIC:02). These PVs can be changed and chich of the tow motors does pitch and yaw can change so these are not set in stone.
  5. When the laser is roughly centered on the X-ray spot (the laser should be on the order of 100-150 um), the X-ray beam needs to be made similar in size at the interaction point to the laser.  In order to do this at CXI, insert Be lenses at the DG2 location to focus the beam upstream of SC1 and produce a larger, divergent beam at the IP.
  6. Hello

 

  • No labels