160 MeV H- injection into the CERN PSB
The H- beam from the proposed LINAC4 will be injected into the four existing rings of the PS Booster at 160 MeV. A substantial upgrade of the injection region is required, including the modification of the beam distribution system and the construction of a new H- injection system. This paper discusses beam dynamics and hardware requirements and presents the results of optimisation studies of the injection process for different beam characteristics and scenarios. The resulting conceptual design of the injection region is presented, together with the main hardware modifications and performance specifications.
INJECTION PAINTING AND ASSOCIATED HW FOR 160 MeV PSB H
Linac4 will replacethe currentlyusedLinac2 in the LHC injector chain. The motivation is to increase the protonflux availability for the CERN accelerator complex and eventu- ally achieve the LHC ultimate luminosity goals. Linac4 will inject 160 MeV Hions in to the four existing rings of the PS Booster (PSB). A new charge-exchange multi turn injection scheme will be put into operation and re- quires a substantial upgrade of the injection region. Four kicker magnets (KSW) will be used to accomplish trans- verse phase space painting in order to match the injected beams to the requiredemittances. This paperpresentshard- ware issues and related beam dynamics studies for several painting schemes. Results of optimization studies of the injection process for different beam characteristic and sce- narios are discussed.
Effect of antioxidants, on deterioration by partial discharge in LDPE and XLPE [insulation materials]
The effect of antioxidants in low-density polyethylene (LDPE) and cross-linked polyethylene (XLPE) on deterioration by partial discharge (PD) was investigated. Experiments were conducted using LDPE and XLPE samples containing phenolic antioxidants. Samples subjected to the PD were analyzed using atomic force microscopy and Fourier transform infrared analysis (AFM and FTIR). AFM images demonstrated that the magnitude of pits created in the sample containing antioxidants was smaller than that in samples containing no antioxidant. FTIR showed that oxidative degradation occurred on LDPE and XLPE surfaces when they were subjected to PD. These results confirmed that the amount of oxidized substances was smaller in samples containing phenolic antioxidants than in those containing no antioxidant. This report elucidates the mechanism of antioxidant action on deterioration by PD.