HB2014 - List of Authors (Baudrenghien, P.)

Paper

Title

Page

Upgrades of the RF Systems in the LHC Injector Complex

165

H. Damerau, M.E. Angoletta, T. Argyropoulos, P. Baudrenghien, A. Blas, T. Bohl, A.C. Butterworth, A. Findlay, R. Garoby, S.S. Gilardoni, S. Hancock, W. Höfle, J.C. Molendijk, E. Montesinos, M.M. Paoluzzi, D. Perrelet, C. Rossi, E.N. Shaposhnikova
CERN, Geneva, Switzerland

In the framework of the LHC Injector Upgrade (LIU) project the radio-frequency (RF) systems of the synchrotrons in the LHC injector chain will undergo significant improvements to reach the high beam intensity and quality required by the High-Luminosity (HL) LHC. Following the recent upgrade of the longitudinal beam control system in the PS Booster (PSB), tests with Finemet cavities are being performed in view of a complete replacement of the existing RF systems in the PSB by ones based on this technology. In the PS a similar wide-band Finemet cavity has been installed as a longitudinal damper. New 1-turn delay feedbacks on the main accelerating cavities to reduce their impedance have also been commissioned. Additional feedback and beam control improvements are foreseen. A major upgrade of the main RF system in the SPS by regrouping sections of its travelling wave cavities, increasing the number of cavities from four to six, will reduce beam-loading and allow higher intensities to be accelerated. The upgrade includes the installation of two new RF power plants and new feedback systems. All upgrades will be evaluated with respect to their expected benefits for the beams to the LHC.

Slides TUO1AB02 [4.317 MB]

THO4LR03

Studies on Controlled RF Noise for the LHC

414

H. Timko, P. Baudrenghien, E.N. Shaposhnikova
CERN, Geneva, Switzerland
T. Mastoridis
CalPoly, San Luis Obispo, California, USA

RF phase noise is purposely injected into the LHC 400 MHz RF system during the acceleration ramp for controlled longitudinal emittance blow-up, in order to maintain longitudinal beam stability. Although the operational blow-up works reliably, studies of the injected RF noise are desirable not only to allow for a better-controlled, more flexible blow-up, but also for other applications such as the mitigation of machine-component heating through appropriate bunch shaping. Concerning the noise injection, an alternative algorithm was developed and implemented in the hardware, but first tests revealed unexpected modulation of the achieved bunch length along the ring, and subsequently, theoretical studies have been launched. In this paper, we present a summary of ongoing measurement analysis and simulation studies that shall explain previous observations, predict what can be expected in different cases, and thus help to optimise the RF noise in general.

Slides THO4LR03 [1.440 MB]

Paper	Title	Page
TUO1AB02	Upgrades of the RF Systems in the LHC Injector Complex	165
	H. Damerau, M.E. Angoletta, T. Argyropoulos, P. Baudrenghien, A. Blas, T. Bohl, A.C. Butterworth, A. Findlay, R. Garoby, S.S. Gilardoni, S. Hancock, W. Höfle, J.C. Molendijk, E. Montesinos, M.M. Paoluzzi, D. Perrelet, C. Rossi, E.N. Shaposhnikova CERN, Geneva, Switzerland
	In the framework of the LHC Injector Upgrade (LIU) project the radio-frequency (RF) systems of the synchrotrons in the LHC injector chain will undergo significant improvements to reach the high beam intensity and quality required by the High-Luminosity (HL) LHC. Following the recent upgrade of the longitudinal beam control system in the PS Booster (PSB), tests with Finemet cavities are being performed in view of a complete replacement of the existing RF systems in the PSB by ones based on this technology. In the PS a similar wide-band Finemet cavity has been installed as a longitudinal damper. New 1-turn delay feedbacks on the main accelerating cavities to reduce their impedance have also been commissioned. Additional feedback and beam control improvements are foreseen. A major upgrade of the main RF system in the SPS by regrouping sections of its travelling wave cavities, increasing the number of cavities from four to six, will reduce beam-loading and allow higher intensities to be accelerated. The upgrade includes the installation of two new RF power plants and new feedback systems. All upgrades will be evaluated with respect to their expected benefits for the beams to the LHC.
	Slides TUO1AB02 [4.317 MB]

THO4LR03	Studies on Controlled RF Noise for the LHC	414
	H. Timko, P. Baudrenghien, E.N. Shaposhnikova CERN, Geneva, Switzerland T. Mastoridis CalPoly, San Luis Obispo, California, USA
	RF phase noise is purposely injected into the LHC 400 MHz RF system during the acceleration ramp for controlled longitudinal emittance blow-up, in order to maintain longitudinal beam stability. Although the operational blow-up works reliably, studies of the injected RF noise are desirable not only to allow for a better-controlled, more flexible blow-up, but also for other applications such as the mitigation of machine-component heating through appropriate bunch shaping. Concerning the noise injection, an alternative algorithm was developed and implemented in the hardware, but first tests revealed unexpected modulation of the achieved bunch length along the ring, and subsequently, theoretical studies have been launched. In this paper, we present a summary of ongoing measurement analysis and simulation studies that shall explain previous observations, predict what can be expected in different cases, and thus help to optimise the RF noise in general.
	Slides THO4LR03 [1.440 MB]