In this mode, you will need to coordinate with the Target Expert on shift regarding the planned duration of time spent in this mode.
This mode will be alternated with the Production Mode during normal operations with microwaves to keep up with the LHe production from the QT system.
Configuration / Things to maintain
| Microwaves | OFF |
| NMR | Taking Data |
| Fridge | Only the Backing Pump (Rotary Vane pump) should be running, and the rest of the roots pumps should be OFF Adjust fridge RUN/Bypass valve (to ~0.5 turns) to keep the fridge LHe level around 50%, and then close the run valve. |
| Magnet | Ensure the magnet has enough LHe. Discuss with the Target Expert when to implement Switching from Production Mode to Hold Mode Ensure Magnet LN2 level is above 50%, if not refill it. |
| QT System | Ensure the purifier LN2 level is above 50%, if not refill it. Ensure both liquefiers are producing LHe with the rate of ~ 4 L/ hr. |
Outlet Flows
| Outlet Flow (in slm) | How to check and control | |
|---|---|---|
| Fridge | 8 | How to control the Fridge Return flow |
| Separator | 20 | How to control the Separator Return flow |
| Magnet | ~7 (on pressure PID at 0.9 psi) | (link to a page) |
Conditions
- Fridge parameters when the fridge is in Hold Mode
- QT system conditions when the fridge is in Hold Mode
- Magnet conditions when the fridge is in Hold Mode
- Cryo-control parameters / conditions when the fridge is in Hold Mode
- Microwave parameters / conditions when the fridge is in Hold Mode
- Target Lifter conditions when the fridge is in Hold Mode
- UVA-NMR conditions when the fridge is in Hold Mode