Practical guide of the temperature switch between nitrogen and helium¶

Performing experiment at room temperature : 240K --> 300K

Step 1 : Make sure N2 valve is open and He is closed
Step 2: FOURC > roomT (# set temperature to 1st and 2nd controller to 130K and 110K)
Step 3 : Make sure in the controller 1 (Input A) and B (input C), it will to reach the temperature 96K and 110K .
Step 4: FOURC > flow_set 6 ( # talk to Staff Scientist for the desired flow rate of your experimental setup)
Step 5 : FOURC > te 300 (# set the temperature to 300K)

Cooling temperature of cryocooler with N₂ : room temperature 240K --> 95K

Step 1 : Open the N₂ valve and close He valve
Step 2 : FOURC > prepnitrogen (# it will setup the temperature in the Lakeshore controller)
Step 3 : FOURC > te 170 (# lowering temperature to 170K)
Step 4: FOURC > flow_set 9 ( # talk to Staff Scientist for the desired flow rate of your experimental setup)

Please use Helium sensibly!

Cooling temperature of cryocooler with He : 85K --> 13K (also if you want only room temperature 300K and 15K) (change to N₂ to He flow)

Step 1 : FOURC > te 230 (# it will setup the temperature in the Lakeshore controller) If the ice did not melt
Step 2 : FOURC > flow_set 9
Step 3 : Turn on the He valve and close N2 valve together

Step 4 : FOURC > runninghelium (# it will setup the temperature in the Lakeshore controller)
Step 5 : Wait for base temperature (Input A ~5K Input C ~36K) to stabilize (look at the plot below)
Step 6 : FOURC > te 14 (# lowering temperature to 14K or others)
Step 7: FOURC > spin_xtal_phi (# rotate sample 360-->0 and 0-->360 degree in phi directions and you can STOP that by control C )

Heating temperature of cryocooler : 13K --> 85K (change to He to N₂ flow)

Step 1 : FOURC > prepnitrogen (# it will setup the temperature setpoints 87K and 83K in the Lakeshore controller Input A and input C)
Step 2 : FOURC > te 180 (# it will setup the desired sample temperature; here sample temperature is 180 K)
Step 4 : Make sure all the temperature is above 80 K (Input A 86 K, Input B (sample temperature) and Input C 83K in PLD controller)

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Danger

N₂ in all conditions should be above 80K (N₂ (channel A, B, C) --> all temperature-->80K)

Step 4 : FOURC > te 100 (# increase temperature to 100K or any other desired temperature)

Room Temperature to base : 300K --> 15K (change N₂ to He flow)

Step 1 : FOURC > prepnitrogen (# it will setup the temperature in the Lakeshore controller channel A = 85K and channel B = 83K)
Step 2 : FOURC > Wait until the temperature of the channel A and C is stabilize to 85K and 83K
Step 3 : FOURC > te 230 (# it will setup the temperature in the Lakeshore controller)
Step 4 : FOURC > flow_set 9
Step 5: you need to wait until the temperature of the sample is 230K (it might be lower)
Step 6 : Turn on the He valve and close N2 valve together

Step 7 : FOURC > runninghelium (# it will setup the temperature in the Lakeshore controller)
Step 8 : Wait for base temperature (Input A ~5K Input C ~41K) to stabilize (look at the plot below)
Step 9 : FOURC > te 15 (# lowering temperature to 15K or others)
Step 10: FOURC > spin_xtal_phi (# rotate sample 360-->0 and 0-->360 degree in phi directions and you can STOP that by control C )

Heating temperature of cryocooler : 13K --> 300K (change to He to N₂ flow)

Step 1 : FOURC > prepnitrogen (# it will setup the temperature setpoints 85K and 83K in the Lakeshore controller Input A and input C)
Step 2 : FOURC > te 230 (# it will setup the desired sample temperature; here sample temperature is 220 K)
Step 3 : Make sure all the temperature is above 80 K (Input A 87 K, Input B (sample temperature) and Input C 83K in PLD controller)

Danger

N₂ in all conditions should be above 80K (N₂ (channel A, B, C) --> all temperature-->80K)

Step 4 : Turn on the N2 valve and close He valve together
Step 5 : FOURC > roomT (# it will setup the temperature setpoints 130K and 110K in the Lakeshore controller Input A and input C and it will to reach the temperature 97K and 110K.)
Step 6 : FOURC > flow_set 6 (# increase temperature to 100K or any other desired temperature)
Step 7 : FOURC > te 300 (# increase temperature to 100K or any other desired temperature)

Performing experiment above room temperature : 300K --> 500K

Step 1 : Make sure N2 valve is open and He is closed
Step 2: FOURC > prephighT (# increase temperature to 1st and 2nd controller to 235K and 220K)
Step 3 : FOURC > flow_set 6
Step 4 : Make sure in the controller 1 (Input A: 103K and B input C: 150K), it will to reach that temperature and stabilize.
Step 5 : FOURC > te 480 (# increase temperature to 400K)

Note: Above 480K, it took long time to go 498K

Performing experiment from high temperature to room temperature : 500K --> 300K

Step 1 : Make sure N2 valve is open and He is closed
Step 2: FOURC > prepnitrogen (# increase temperature to 1st and 2nd controller to 85K and 83K)
Step 3 : Make sure in the controller Input A and Input C, it will to reach the temperature 85K and 83K.
Step 4 : FOURC > te 300 (# increase temperature to 300K)

Turn off the temperature controller

Problem : Ice formation at low temperature¶

a) Figure 1 : Check the distance between the cryo-stream and sample (it should be as close as possible)
b) Figure 2 : Continuously rotate the phi umv phi 360; umv phi 0 at low temperature
c) Figure 3 : Check the gas flow and if needed talk to the staff scientist
- FOURC> flow_set <number>
- FOURC> flow_get

Step 1 : Open terminal and type StripTool
Step 2 : Connect to epics PVs
Need to connect to epics PVs that you want to monitor
- LAKESHORE2:KRDG0
- LAKESHORE2:KRDG1
- LAKESHORE2:KRDG2
y-axis click “Modify” button (same y axis for all the curves)

Talk to Beamline Scientist or operators --- DONOT TRY THIS WITHOUT ASKING

If the your setup is in nitrogen condition (300K - 80K) and suddenly temperature is dropiing drastically and you don't have controls
Switch the valve Nitrogen to Helium