14. Serial Crystallography: CFEL TapeDrive

• • 14.1 Sample characteristics and preparation
  • 14.2 Connecting sample to ElveFlow, sample exchange
  • 14.3 TapeDrive operation
    • • Tape
      • Sample nozzle
      • Temperature control/Chiller
      • Gas nozzle
      • IR camera
  • 14.4 Tape roll exchange
    •  
  • 14.5 Chopper
  • 14.6 Data collection
  • 14.7 Troubleshooting
    • • Tape stopped
      • Nozzle motors are not responding
      • Sample flow is not responding to higher pressure

14.1 Sample characteristics and preparation

suspension of microcrystals, at least 200 µL with 20% crystal density(more is always better), size range: 2-30 µm, tip: bring some mother liquor for washing, filtering, diluting etc.

Preparation:

• filter through 30 µm cell filter (green) into Eppendorf or Falcon (original!) tube

14.2 Connecting sample to ElveFlow, sample exchange

• • ==

After filtration, screw the ElveFlow connector to your Eppendorf or Falcon tube. Make sure that the yellow-ish line goes to the bottom of your tube. You can adjust the length by unscrewing the blue fitting on top and pushing/pulling the yellow-ish line. Don't forget to tigthen the blue fitting afterwards!

Be aware to which channel and nozzle line your sample is connected.

            Red → Channel 1, crystal line (nozzle capillary without marks/with red marks)

            Green → Channel 2, substrate line (nozzle capillary is marked in black)

After finishing data collection, flush all lines by connecting an Eppi or syringe filled with ddH₂O.

14.3 TapeDrive operation

• • ==

The TapeDrive is controlled through kamzik. To open kamzik, start the server. A terminal will open and shortly after a small window.
Now start the client. Same thing, a terminal will open, shortly after a small window.

Click 'Devices' in the client session to open the control window.

Tape

• Click on the 'main tape' icon
• Change the velocity by typing anything from 0.3-3.0 mm/s
• Common velocity is 1.0-1.5 mm/s
• kamzik displays the used tape in m and %. At 98% the tape will automatically stop since the rolls need to be exchanged at this point.
  
  
• 

Sample nozzle

• Click an the 'nozzle' icon.

• The nozzle position can be adjusted in xyz by clicking on the arrows up and down. (Double arrow = 10 steps). Step size can be varied, 1mm steps are rather big and should be used carefully.
  The absolute position is not calibrated and therefore changes after each restart of kamzik.

  !!! During data collection make sure in which direction you are moving, do not move nozzle into beam !!!
  
  Adjust the nozzle position by eye until it nearly touches the tape and roughly meets the X-ray interaction point. Then, move to the control hutch to use the on-axis microscope for fine adjustment. Move the nozzle tip to the beam position (red X) and write down the absolut nozzle position. From there move the nozzle in +x to your desired distance.Different distances combined with the tape speed result in several delay times for time-resolved experiments. 

  	direction	recommended step size for visual adjustment	recommended step size during data collection
  +x	away from X-ray interaction point	1.0 - 0.5 mm	0.1 - 0.2 mm
  +y	up	1.0 - 0.5 mm	0.1 - 0.2 mm
  +z	towards detector tower, away from tape	0.5 - 0.2 mm	0.1 - 0.2 mm be careful with -z, tape could be pushed out of focus

  
  
  

• 

Temperature control/Chiller

• The chiller circulates fluid through the gas nozzle.

Gas nozzle

IR camera

Once the hutch is interlocked, set remote control to the TapeDrive laptop by opening a terminal and executing the following command:

                                        xfreerdp +clipboard /size:1920x1080 /u:Cfelusr /v:cfeld-pcx22611
                                        password: written on control laptop (changes every 6 months)

14.4 Tape roll exchange

The tape stops automatically at 98% used length, if you need to change the rolls for orther reasons, stop the tape (velocity = 0.0 mm/s).

• Remove the (almost) empty feeder roll by pulling it upwards.
• Cut the tape with some cm overlap to glue to the new roll. Do not discard empty roll!
• Get a new tape roll (bottom left on the cart). Polypropylen 15 µm
• Cut the first cm of the new tape roll, directly behind the black sticky part.
• Place new roll on roll holder and use sticky tape to attach the end of the old tape to the beginning of the new roll.
• Open magnetic tape stabilizer on the left side. !!!BEAMSTOP!!!
• Start the tape (3mm/s). Once the connetion side has arrived at the collector roll, stop the tape (0mm/s).
• Again, cut the tape directly behind the connection side. Replace the the old roll with the empty one. Old roll can be discarded.
• Attach new tape to the empty roll by using some sticky tape.
• Close tape stabilizer.
• Reset tape counter in kamzik by clicking "<Call>" in "Main-Tape".

• • ===

14.5 Chopper

start chopper gui from terminal:

14.6 Data collection

Once the hutch is interlocked, set remote control to the TapeDrive laptop by opening a terminal and executing the following command:

                                           >>usually the terminal is open, just repeat previous command with arrow up, enter and type in the password

Click "Start" icon in kamzik.

14.7 Troubleshooting

• Tape stopped

  • Tape roll empty?
  • motor connected (icon green)?

• Nozzle motors are not responding

  • displayed in green=connected?
  • nozzle holder colliding somewhere?
  • motor limits reached? → position displayed in red

• Sample flow is not responding to higher pressure

  • channel turned on?
  • Sample empty?
  • Nozzle or lines clogged? → flush with water, change nozzle