TRIODE SPUTTER - ION PUMPS
FEATURES
Triode sputter-ion pumps are suited for generating a heavy-hydrocarbon-free
ultra-high-vacuum. They are superior to diode and noble sputter-ion pumps in pumping speed
and long-term stability for inert gases. They are also able to start at higher pressures
than diode and noble pumps.The pumps allow the use of the pump current indication for
pressure measurement or leak detection (oxygen can be used as the test gas).
PRINCIPLE OF OPERATION
The triode sputter-ion pump operates by ionizing gas molecules in a magnetically confined
cold-cathode discharge. The gas is ionized by electrons emitted from titanium cathodes.
The positive gas ions hit the cathode surface and cause its sputtering.
1.Active gases react with sputtered titanium and form stable chemical compounds.
2.Hydrogen is diffused into the cathode structure (besides being gettered).
3.The ions of heavy inert gases are neutralized by glancing collisions with the cathodes and then they are buried as high energetic neutrals (in the anode or pump walls) with sputtered titanium.
| Maximum starting pressure | 1 Pa | |
| Operating range | 10-2 - 10-9 Pa | |
| Ultimate pressure | 10-9 Pa | |
| Cathode voltage | -6 kV | |
| Magnetic induction between poles | 0.12 T | |
| Maximum operating temperature | 250 oC | |
The titanium strip cathodes and the stainless steel anode are placed in the vacuum tight envelope. High voltage -6 kV is applied to the cathodes. The anode is grounded.The magnetic field is created by external ferrites bakeable up to 250 oC.
APPLICATION
- Laboratory UHV systems
- Coating systems
- Electron device processing
- Molecular beam epitaxy
- Surface analysis
- Particle accelerators