The vacuum system of MAX IV 3 GeV storage ring
Some of the characteristics of recent ultra-lowemittance (fourth generation) storage-ring designs and possibly future diffraction-limited storage rings are a compact lattice combined with small magnet apertures. Such requirements present a challenge for the design and performance of the vacuum system. The vacuum system should provide the required vacuum pressure for machine operation and be able to handle the heat load from synchrotron radiation. Small magnet apertures result in the conductance of the chamber being low. One way to provide the required vacuum level via distributed pumping, which can be realized by the use of a non-evaporable getter (NEG) coating of the chamber walls. In addition, the chamber walls can work as distributed absorbers if they are made of a material with good thermal conductivity, and distributed cooling is used at the location where the synchrotron radiation hits the wall. The vacuum system of the 3 GeV storage ring of MAX IV is unique, it is has a very small aperture, combined with being 100% NEG coated, a feature which is the first to be implemented in fourth generation storage rings.
Lund University, MAX IV Laboratory:
- Eshraq Al-Dmour, Vacuum engineer
- Marek Grabski, Vacuum engineer
- Implementation of small vacuum aperture all over the storage ring.
- 100% NEG coating as source of pumping down.
- Realizing the technique for the power removal from synchrotron radiation on the chambers wall.
- Lund University