Speaker
Description
The LINAC 4 is a negative hydrogen linear ion injector, scheduled to become the next proton bream source for the Large Hadron Collider (LHC) at CERN. A Radio Frequency Quadrupole (RFQ) is the first stage of acceleration in LINAC 4, capturing a 70mA, 45keV beam from the ion source and accelerating it to 3MeV. After one year of test operation the RFQ was inspected with an endoscope and surface modification was observed on the copper RFQ vanes. This surface modification appears to be a combination of blistering due to H- beam loss and vacuum arcing, which raises the possibility of beam-loss induced vacuum arcing. A study was launched with goals of investigating and understanding this phenomenon and identifying potential alternative materials (copper alloys or transition metals) with a combined better resilience to blistering and breakdowns. This talk presents a general overview and motivation of this study, while other talks will focus on the first experiments of ion irradiation and the related metallurgical analyses and breakdown resistance characterization.
