Titan Cassette Loading                                2014vdb

                                   

1.Begin with carefully screened pre-assembled cartridges.

a.The grid and the C-clip ring should fit well in the cartridge without any parts hanging out past the edge – this prevents jamming the autoloader. (critical!)

b.The grids are loaded into the cartridges with the carbon films facing the flat side of the cartridges.

c.The cartridges are stored in slots in a special cryo-grid box (tan grid box). The cup side of a cartridge (open top side) faces the notch at the edge of the cryo-box to make things easier for later operation,

Note: The cover of the off white grid box made by FEI can be replaced with one of our homemade covers (lids) that uses the larger hex screw.

2.Cool down the cassette loading station (large white workstation) with liquid nitrogen

a.Orient the loading station with the “foot” and nanocab port to the left

b.Wait until liquid N2 bubbling subsides.

3.Place a dry cassette into the loading station with the cassette holding tool or gloves

        a. Never touch anything that will go into the scope with bare hands!

b.Remove old cartridges from the cassette with the special cartridge tweezers.

c.The cartridge tweezers have “ears” that stick out on both sides close to the tip.

4.Put the cryo-cartridge boxes holding assembled cartridges into the loading station

a.Check that Nitrogen level covers boxes.

b.Remove lid.

5.Remove the first cartridge from the box

a.Cool down the special cartridge tweezers in liquid Nitrogen.

b.Insert the tweezers fully into a slot in the cryo-grid box to grab a cartridge.

c.Make sure the tweezers grab both edges of the cartridge and the tip does not touch the enclosed grid.

6.Insert this cartridge all the way into a slot on the cassette.

a. Always leave slot # 1 empty!  This is the slot that will be used first if the inventory is lost due to a computer crash or if there was a grid left on the stage.

b.A cartridge should go in the slot between the thin brass finger and the L-shaped silver brackets. Never force a grid into position if it is difficult to insert or remove at a particular slot.

c.Make sure both ears of the cartridge tweezers touch the cassette so that the cartridge is fully lowered into the slot.

d.The cup side of the cartridge (top) should face the foot of the cassette (the Left end with smaller numbers). In fact, if the cartridges are oriented in the cryo-grid box with the cup side facing the notch on the grid box, you can move it from the grid box directly over to the slot in the cassette without changing the orientation. It will already be facing the right direction.

7.Check the mounting of the cartridge in the slot of the cassette.

a. GENTLY tap on the upper side of the cartridge with the tip of the cartridge tweezers to make sure it is fully seated and being held in place by the brass fingers. It is important not to use too much force positioning the cartridge or it may stick in the slot and cause the autoloader to crash.

b. Make sure the cartridge sits straight up vertically, not tilted or twisted.

c. Make sure not to push the cartridges too far, or they will go thru the slot and to the bottom of the cassette.  

d. If anything comes loose from a cartridge, it and any pieces MUST be removed from the cassette before putting the cassette into the autoloader.

8. Repeat for remaining cartridges.

a.If loading less than 6 cartridges, it may be better to put them into every other slot so there is space between neighboring cartridges for the tweezers to maneuver.

b.It is advisable to keep a test sample (such as the grating replica) in the cassette or in the microscope column.

9. Move cassette into capsule (also called the nanocab)

a. Mount capsule on the foot end of workstation.  Make sure it is latched on.

b. Cool down capsule.  Wait for bubbling to subside.

c.Top off nitrogen in workstation and wait.  This gives the nitrogen gas time to replace any moist air in the work station.  

d. Remove the lids and quickly transfer the cassette  into the capsule.

  1. Slide the cassette holding tool to the left so that the rod is inserted into the hole in the cassette
  2. squeeze the button to grip the cassette
  3. Lift the cassette and move it quickly to the left into the capsule
  4. let go of the button and slide the holding tool back the the right and put it back in its resting location.

10. Prepare to Dock the Capsule onto the Scope.

a.Check the temperature of the Scope autoloader and grippers

        1.        the cassette gripper must be -154F

        2.        the cartridge gripper must be -175F

b.Remove the capsule from the workstation

c.Fill the capsule to the top with liquid nitrogen (Important to keep grids frost free!).

d.Check that the pin on the top of the capsule is UP and not frozen

e.Cover the capsule with the lid

11. Mount the Capsule onto the Scope.

a.Move the capsule to the scope

b.Remove the lid

c. Slide the capsule into the docking position underneath the autoloader by sliding it (curved side first) all the way into the slot.

12. See Titan Krios Basic Operation Procedures for docking and inventory procedures