• G. Bregliozzi
  CERN, Geneva

In the CERN Large Hadron Collider, about 6 km of the UHV beam pipe are at ambient temperature and serve as experimental or utility insertions. The vacuum of these sectors rely on TiZrV non-evaporable getter (NEG) coating to achieve very low pressure. In the case of venting to atmosphere, the use of NEG coatings implies the bake-out of the vacuum sector to recover the low pressure and reactivate the NEG coatings. A new method to vent a vacuum sector to atmosphere allows performing short interventions without losing completely the performance of the already activated NEG coating. The principle is to over-pressurize the vacuum sector with neon gas which is not pumped by the NEG coatings, remove the faulty component and then pump down the sector again. The injection of such a gas in the vacuum sector aims at preserving the saturation of the NEG coatings during the exchange of the component. A detailed description of this new venting system will be presented and discussed. Preliminary results obtained from a laboratory venting system and its evaluation in the LHC tunnel to replace existing components will be presented.