| Features: |
- UHV compatible, all metal seals
- Operating gases: He, Ar, Xe, H, Ne, …
- Microwave power: >400W
- Photocurrent: HeI monochromated using SPECS TMM 304 into 1.6mm diameter spot: 40nA (max)
- Photocurrent density (system as above): >20nA/mm2
- Photocurrent density in combination with ellipsoidal capillary (ETC): >120nA / mm2
- Photon flux: 1x1017
- Power supply: 19" rack mounting connected to UVLS by 5m HV cable
- Operating pressure in analysis chamber: Typically in 10-7 mbar range with single-stage differential pumping on UVLS (standard) and turbo pump of a few hundred l/s on the chamber.
- Operating pressure in analysis chamber as above but with TMM 304 monochromator and pumped ETC: <1x10-10
Optional Feature: Focus Capillary
High resolution photoemission measurements demand not only a highest performance electron spectrometer, but also a UV source with high flux density and small spot size, especially for angular resolved studies. SPECS has developed a focused UV source on the basis of the proven technology of the UVS 300 source. Using a special capillary, this source can be focused down to a spot size of 500 micrometers.
The new SPECS UVLS is a microwave plasma-based UV light source developed combining microwave plasma source expertise from the successful PCS-ECR and MPS-ECR sources with our experience in focussed ultimate brilliance UV sources.
The UVLS is a filamentless source and is therefore not subject to the filament ageing of electron impact plasma UV sources. Instead the He plasma is created directly in the quartz output capillary leading to excellent coupling of the generated UV to the chamber or monochromator. This design provides long term plasma stability making the source suitable for use even with heavier gases like Ar and Xe.
Because the microwaves are generated directly in the UVLS a simple high-voltage cable (5m standard length) is sufficient to supply power to the UVLS. Regular water-cooling and an on-board fan are all that is needed for cooling. The use of all-metal seals mean that the source is O-ring and elastomer free.
The microwave system has been designed to be highly tolerant of the small perturbations common to plasma operation with the result that the plasma is highly stable. Simple tuning is provided to allow optimisation of the microwave coupling under a given set of conditions but once these are established no further adjustment is necessary. Many users will find the factory setting perfectly adequate and no adjustment will be needed. The plasma starts readily on introducing gas into the UVLS obviating the need for "strikers" or other starting mechanisms.