Vacuum Pump Procedures
- Steve Gibson
Scratchpad for procedures being developed/iterated on.
Operational notes
Turbo pump runs consistently at 1000 Hz when operating normally
When running at 1000 Hz, the turbo pump bearing temp is usually between 45 deg C and 50 deg C. If running high, check Vaisala room temp plot. It usually changes in step with room temp.
Pump Down From Atmosphere
TBD. Remember addition of scroll pump to help the roots with initial roughing.
Turbo does not really get going until pressure is < 1 Torr. If started earlier it will partially spin up, but won’t head towards 1000 Hz until pressure is low enough.
Pump Down From Partially-Evacuated Chamber
| Roots Pump | Turbo Pump | Gate Valve | Cart Pressure | Chamber Pressure | |
|---|---|---|---|---|---|---|
| 1 | Starting point Gate valve closed, roots pump running, and chamber under vacuum. | ON | OFF | CLOSED | 1.5 x 10-2 Torr | Below atmosphere |
| 2 | Log into vacuum pump webserver On a computer on the KPF private network, open a web browser and go to 192.168.23.125. At top right of page, log in using the kpfdev account credentials. Remain on the ‘Main’ page. | ON | OFF | CLOSED | 1.5 x 10-2 Torr | Below atmosphere |
| 3 | Find PDU and Outlet for gate valve power supply On the same computer, open another web browser tab/window and go to the https://keckobservatory.atlassian.net/wiki/spaces/KPFElectronics/pages/1511915964. Find the gate valve on this page and note:
| ON | OFF | CLOSED | 1.5 x 10-2 Torr | Below atmosphere |
| 4 | Log into PDU webserver On same computer, open another web browser tab/window and go to the IP address for the gate valve PDU. Log in using the kpfdev account credentials. Navigate to the ‘Outlet’ page shown in hierarchy at top left of screen. | ON | OFF | CLOSED | 1.5 x 10-2 Torr | Below atmosphere |
| 5 | Turn on power to gate valve power supply On the PDU webserver, turn on power to the appropriate outlet for the gate valve. This turns on power to the gate valve power supply only, and does not actually open the gate valve. | ON | OFF | CLOSED | 1.5 x 10-2 Torr | Below atmosphere |
| 6 | Turn on turbo pump Now go back to the webserver page for the vacuum pump. Turn on the vacuum pump using the ‘START' button at bottom center of page. The pump will start spinning up and the pump frequency will start increasing. | ON | ON | closed | Quickly changes to 10-5 Torr | Below atmosphere |
| 7 | Manually open gate valve Press the output enable button on the lab power supply. The gate valve will open with a ‘whoosh’ | ON | ON | OPEN | Rises as it reacts to pressure differential | Starts dropping |
| 8 | Ending point Roots and turbo running, chamber is evacuating towards ultimate pressure. | ON | ON | OPEN | VCART_HIVAC gauge usually sits at 3x10-5 Torr | Dropping |
Closing Gate Valve
| Roots Pump | Turbo Pump | Gate Valve | Cart Pressure | Chamber Pressure | |
|---|---|---|---|---|---|---|
| 1 | Starting point Gate valve open, pumps running, and chamber under vacuum. | ON | ON | open | 10-5 Torr | 10-5 Torr |
| 2 | Log into vacuum pump webserver On a computer on the KPF private network, open a web browser and go to 192.168.23.125. At top right of page, log in using the kpfdev account credentials. Remain on the ‘Main’ page. | ON | ON | open | 10-5 Torr | 10-5 Torr |
| 3 | Find PDU and Outlet for gate valve power supply On the same computer, open another web browser tab/window and go to the https://keckobservatory.atlassian.net/wiki/spaces/KPFElectronics/pages/1511915964. Find the gate valve on this page and note:
| ON | ON | open | 10-5 Torr | 10-5 Torr |
| 4 | Log into PDU webserver On same computer, open another web browser tab/window and go to the IP address for the gate valve PDU. Log in using the kpfdev account credentials. Navigate to the ‘Outlet’ page shown in hierarchy at top left of screen. | ON | ON | open | 10-5 Torr | 10-5 Torr |
| 5 | Close gate valve On the PDU webserver, turn off power to the appropriate outlet for the gate valve. This closes the gate valve. | ON | ON | closed | Starts to fall towards 10-8 Torr | Starts to rise |
| 6 | Turn off turbo pump Now go back to the webserver page for the vacuum pump. Turn off the vacuum pump using the red ‘STOP' button at bottom center of page. Note pump will not instantaneously stop, but the pump frequency will slowly start to drop. The user has no control here, this process is internally regulated by the pump. Note it might take 1.5 hours for it to gracefully slow from 1000 Hz to 0 Hz. | ON | OFF | closed | Once pump frequency slows down below 500 Hz the pressure will start to rise. | Rising |
| 7 | Ending point The turbo has stopped rotating and is showing a frequency of 0 Hz, and a power of 0 W. Roots pump is still running, and has reached a steady pressure of 1.5 x 10-2 Torr. | ON | OFF | closed | 1.5 x 10-2 Torr | Rising |