R2-A Overview
Two-Stage High-Vacuum Rig
| Target Pressure | ATM → ~10⁻⁷ mbar |
| HV Pump | Turbomolecular pump (67 L/s) |
| Backing Pump | Rotary vane pump (3.3 m³/hr) |
| Flange Standards | KF25 KF40 KF16 |
| Components | 13 major + 6 pipe runs + adapters |
| Key Feature | Throttle valve for conductance control |
| Key Adapters | KF16→KF25 (foreline), KF16→KF25 (gauges) |
Two-stage pumping: The roughing/backing pump (R2-P-RP) brings pressure from ATM to ~1 mbar. The turbo pump (R2-P-HV) then takes over, using molecular momentum transfer to reach ~10⁻⁷ mbar. The backing pump must keep running to maintain the turbo's foreline below ~10 mbar.
Key difference from R1-A: Gate valve isolates the turbo pump. Throttle valve controls conductance between chamber and manifold. Cold cathode gauge measures deep vacuum. Three flange sizes instead of one.