IPAC2012 - List of Keywords (RF-structure)

Paper	Title	Other Keywords	Page
TUPPR033	Improved Modelling of the Thermo-mechanical Behavior of the CLIC Two-Beam Module	vacuum, linac, alignment, simulation	1891
	G. Riddone, T.O. Niinikoski, F. Rossi CERN, Geneva, Switzerland R.J. Raatikainen, K. Österberg HIP, University of Helsinki, Finland A. Samoshkin JINR, Dubna, Moscow Region, Russia
	The luminosity goal of the CLIC collider, currently under study, imposes micrometer mechanical stability of the 2-m-long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module is being tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the revised finite element model developed for the CLIC two-beam module is described. In the current model, the structural behavior of the module is studied in more detail compared to the earlier configurations, in particular for what regards the contact modeling. The thermal and structural results for the module are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done in 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behavior and they will be propagated back to the present thermo-mechanical model.

WEXB01	Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches	radiation, electron, laser, FEL	2091
	D. Xiang SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. DOE under Contract No. DE-AC02-76SF00515. This talk will address advances in the measurement of ultra-short relativistic bunches at femtosecond frontier in high-energy x-ray free-electron lasers (FELs). In general, this presentation will discuss several recently proposed novel techniques (i.e. mapping z exactly to delta * and x , optical oscilloscope , etc.) that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. In particular, this presentation will report on the all-optical, time-resolved method to probe beam longitudinal phase space with femtosecond time scale and 10^-5 energy scale resolution *. The simultaneous measurement of temporal profile and beam slice energy spread after the FEL interaction is also shown to reveal the time-dependent x-ray radiation profile **. Z. Huang et al., PRSTAB 13, 092801. D. Xiang, Y. Ding, PRSTAB 13, 094001. * G. Andonian et al., PRSTAB 14, 072802. ** D. Xiang et al., PRSTAB 14, 112801. *** Y. Ding et al., FEL11.
	Slides WEXB01 [6.873 MB]

THPPC061	A 12 kV, 1 kHz, Pulse Generator for Breakdown Studies of Samples for CLIC RF Accelerating Structures	controls, power-supply, vacuum, radio-frequency	3431
	R.H. Soares, M.J. Barnes, S. Calatroni, J.W. Kovermann, W. Wuensch CERN, Geneva, Switzerland
	Compact Linear Collider (CLIC) RF structures must be capable of sustaining high surface electric fields, in excess of 200 MV/m, with a breakdown (BD) rate below 3×10^-7 breakdowns/pulse/m. Achieving such a low rate requires a detailed understanding of all the steps involved in the mechanism of breakdown. One of the fundamental studies is to investigate the statistical characteristics of the BD rate phenomenon at very low values to understand the origin of an observed dependency of the surface electric field raised to the power of 30. To acquire sufficient BD data, in a reasonable period of time, a high repetition rate pulse generator is required for an existing d.c. spark system at CERN. Following BD of the material sample the pulse generator must deliver a current pulse of several 10’s of Amperes for ~2 μs. A high repetition rate pulse generator has been designed, built and tested; this utilizes pulse forming line technology and employs MOSFET switches. This paper describes the design of the pulse generator and presents measurement results.

Paper

Title

Other Keywords

Page

TUPPR033

Improved Modelling of the Thermo-mechanical Behavior of the CLIC Two-Beam Module

vacuum, linac, alignment, simulation

1891

G. Riddone, T.O. Niinikoski, F. Rossi
CERN, Geneva, Switzerland
R.J. Raatikainen, K. Österberg
HIP, University of Helsinki, Finland
A. Samoshkin
JINR, Dubna, Moscow Region, Russia

The luminosity goal of the CLIC collider, currently under study, imposes micrometer mechanical stability of the 2-m-long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module is being tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the revised finite element model developed for the CLIC two-beam module is described. In the current model, the structural behavior of the module is studied in more detail compared to the earlier configurations, in particular for what regards the contact modeling. The thermal and structural results for the module are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done in 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behavior and they will be propagated back to the present thermo-mechanical model.

WEXB01

Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches

radiation, electron, laser, FEL

2091

D. Xiang
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. DOE under Contract No. DE-AC02-76SF00515.
This talk will address advances in the measurement of ultra-short relativistic bunches at femtosecond frontier in high-energy x-ray free-electron lasers (FELs). In general, this presentation will discuss several recently proposed novel techniques (i.e. mapping z exactly to delta * and x **, optical oscilloscope ***, etc.) that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. In particular, this presentation will report on the all-optical, time-resolved method to probe beam longitudinal phase space with femtosecond time scale and 10^-5 energy scale resolution ****. The simultaneous measurement of temporal profile and beam slice energy spread after the FEL interaction is also shown to reveal the time-dependent x-ray radiation profile *****.
* Z. Huang et al., PRSTAB 13, 092801.
** D. Xiang, Y. Ding, PRSTAB 13, 094001.
*** G. Andonian et al., PRSTAB 14, 072802.
**** D. Xiang et al., PRSTAB 14, 112801.
***** Y. Ding et al., FEL11.

Slides WEXB01 [6.873 MB]

THPPC061

A 12 kV, 1 kHz, Pulse Generator for Breakdown Studies of Samples for CLIC RF Accelerating Structures

controls, power-supply, vacuum, radio-frequency

3431

R.H. Soares, M.J. Barnes, S. Calatroni, J.W. Kovermann, W. Wuensch
CERN, Geneva, Switzerland

Compact Linear Collider (CLIC) RF structures must be capable of sustaining high surface electric fields, in excess of 200 MV/m, with a breakdown (BD) rate below 3×10^-7 breakdowns/pulse/m. Achieving such a low rate requires a detailed understanding of all the steps involved in the mechanism of breakdown. One of the fundamental studies is to investigate the statistical characteristics of the BD rate phenomenon at very low values to understand the origin of an observed dependency of the surface electric field raised to the power of 30. To acquire sufficient BD data, in a reasonable period of time, a high repetition rate pulse generator is required for an existing d.c. spark system at CERN. Following BD of the material sample the pulse generator must deliver a current pulse of several 10’s of Amperes for ~2 μs. A high repetition rate pulse generator has been designed, built and tested; this utilizes pulse forming line technology and employs MOSFET switches. This paper describes the design of the pulse generator and presents measurement results.