IPAC2011 - Table of Session: THPPA (IPAC'11 EPS-AG Prize Presentations)

Paper

Title

Page

Study of Beam Diagnostics with Trapped Modes in Third Harmonic Superconducting Cavities at FLASH

2891

P. Zhang
DESY, Hamburg, Germany
P. Zhang
UMAN, Manchester, United Kingdom

Contribution selected for EPS-AG Prize d). Off-axis beams passing through an accelerating cavity excite dipole modes among other higher order modes (HOMs). These modes have linear dependence on the transverse beam offset from the cavity axis. Therefore they can be used to monitor the beam position within the cavity. The fifth dipole passband of the third harmonic superconducting cavities at FLASH has modes trapped within each cavity and do not propagate through the adjacent beam pipes, while most other cavity modes do. This could enable the beam position measurement in individual cavities. This paper investigates the possibility to use the fifth dipole band for beam alignment in the third harmonic cavity module. Simulations and measurements both with and without beam-excitations are presented. Various analysis methods are used and compared. A good correlation of HOM signals to the beam position is observed.

Slides THPPA00 [2.740 MB]

THPPA01

EPS-AG Sacherer Prize: Beam Optics Developments for SPS, RHIC, LHC, CLIC and ATF2

2894

R. Tomás
CERN, Geneva, Switzerland

Highlights of linear and nonlinear optics studies are presented from various accelerators. At the LHC, optics correction is of critical importance to guarantee safe beam operation. Preparation for LHC optics measurements and corrections has been a major activity during the last decade. In particular, SPS and RHIC have served as excellent research and development machines to test new techniques and instrumentation, such as the measurement of resonance driving terms with and without AC dipoles. Together with a meticulous field quality specification, a careful installation strategy and an elaborate magnet model, these efforts have paid off in the LHC, where a record low beta-beating for hadron colliders below 10% has been achieved. Looking further into the future, the performance of the Final Focus System (FFS) is of critical importance for a future linear collider like CLIC, since it determines the IP beam spot sizes. The large chromatic aberrations required the development of novel non-linear optimization methods. Such techniques have successfully increased the CLIC design luminosity by 70% and an experimental test has been proposed for ATF2 to halve the design IP beam spot sizes.

Slides THPPA01 [1.514 MB]

THPPA02

EPS-AG Budker Prize Presentation: Retrospective of 24 years of RIBF Life

2899

Y. Yano
RIKEN Nishina Center, Wako, Japan

The speaker will look back on 24 years (from 1987 to now) devoted to the RIBF project.

Slides THPPA02 [10.303 MB]

THPPA03

EPS-AG Wideröe Prize Presentation

S.-I. Kurokawa
Cosylab, Ljubljana, Slovenia
S.-I. Kurokawa
KEK, Ibaraki, Japan

This presentation will cover the work for which the Wideröe Prize is awarded.

Slides THPPA03 [10.964 MB]

Paper	Title	Page
THPPA00	Study of Beam Diagnostics with Trapped Modes in Third Harmonic Superconducting Cavities at FLASH	2891
	P. Zhang DESY, Hamburg, Germany P. Zhang UMAN, Manchester, United Kingdom
	Contribution selected for EPS-AG Prize d). Off-axis beams passing through an accelerating cavity excite dipole modes among other higher order modes (HOMs). These modes have linear dependence on the transverse beam offset from the cavity axis. Therefore they can be used to monitor the beam position within the cavity. The fifth dipole passband of the third harmonic superconducting cavities at FLASH has modes trapped within each cavity and do not propagate through the adjacent beam pipes, while most other cavity modes do. This could enable the beam position measurement in individual cavities. This paper investigates the possibility to use the fifth dipole band for beam alignment in the third harmonic cavity module. Simulations and measurements both with and without beam-excitations are presented. Various analysis methods are used and compared. A good correlation of HOM signals to the beam position is observed.
	Slides THPPA00 [2.740 MB]

THPPA01	EPS-AG Sacherer Prize: Beam Optics Developments for SPS, RHIC, LHC, CLIC and ATF2	2894
	R. Tomás CERN, Geneva, Switzerland
	Highlights of linear and nonlinear optics studies are presented from various accelerators. At the LHC, optics correction is of critical importance to guarantee safe beam operation. Preparation for LHC optics measurements and corrections has been a major activity during the last decade. In particular, SPS and RHIC have served as excellent research and development machines to test new techniques and instrumentation, such as the measurement of resonance driving terms with and without AC dipoles. Together with a meticulous field quality specification, a careful installation strategy and an elaborate magnet model, these efforts have paid off in the LHC, where a record low beta-beating for hadron colliders below 10% has been achieved. Looking further into the future, the performance of the Final Focus System (FFS) is of critical importance for a future linear collider like CLIC, since it determines the IP beam spot sizes. The large chromatic aberrations required the development of novel non-linear optimization methods. Such techniques have successfully increased the CLIC design luminosity by 70% and an experimental test has been proposed for ATF2 to halve the design IP beam spot sizes.
	Slides THPPA01 [1.514 MB]

THPPA02	EPS-AG Budker Prize Presentation: Retrospective of 24 years of RIBF Life	2899
	Y. Yano RIKEN Nishina Center, Wako, Japan
	The speaker will look back on 24 years (from 1987 to now) devoted to the RIBF project.
	Slides THPPA02 [10.303 MB]

THPPA03	EPS-AG Wideröe Prize Presentation
	S.-I. Kurokawa Cosylab, Ljubljana, Slovenia S.-I. Kurokawa KEK, Ibaraki, Japan
	This presentation will cover the work for which the Wideröe Prize is awarded.
	Slides THPPA03 [10.964 MB]