6th Evian Workshop

Session

Performance and limitations - part II

16 Dec 2015, 08:30

Hotel Hilton

Conveners

Performance and limitations - part II

• Rogelio Tomas Garcia
• Belen Maria Salvachua Ferrando

15. Instabilities and beam induced rf heating in 2015

Lee Robert Carver

16/12/2015, 08:30

Instabilities were observed during operation at injection, flat top and during the betatron squeeze. This resulted in high chromaticities and octupole currents in all stages of the machine cycle. A series of dedicated measurements at flat top and end of squeeze of the instability threshold was performed which can shine a light on expected performance in 2016. Beam induced rf heating will also...

16. Electron cloud effects

Giovanni Iadarola

16/12/2015, 09:00

The brief experience with 25 ns beam in the LHC at the end of Run 1 suggested that the electron cloud effects were set to pose important challenges to the machine operation during Run 2. In spite of four weeks of dedicated scrubbing run, the 2015 proton run of the LHC fully confirmed this expectation, with the electron cloud severely degrading the beam quality at the beginning of the scrubbing...

17. Beam-beam Head-on and Long Range

Tatiana Pieloni

16/12/2015, 09:30

The 2015 LHC run has shown the beauty of having weaker beam-beam effects with respect to 2012 physics run. The 2015 set-up has been defined to allow Landau octupole and chromaticity to be powered at maximum currents to fight coherent instabilities. Quantitative studies of the impact of reduced crossing angles on the beam and luminosity lifetimes have been used to compare to expectations from...