IPAC2016 - List of Authors (Plassard, F.)

Paper	Title	Page
WEPOR009	Intra-beam IP Feedback Studies for the 380 GeV CLIC Beam Delivery System	2683
	R.M. Bodenstein, P. Burrows, J. Snuverink JAI, Egham, Surrey, United Kingdom F. Plassard CERN, Geneva, Switzerland
	In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR009
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THPMB043	Progress in Ultra-Low β* Study at ATF2	3335
	M. Patecki, D.R. Bett, F. Plassard, R. Tomás CERN, Geneva, Switzerland K. Kubo, S. Kuroda, T. Naito, T. Okugi, T. Tauchi, N. Terunuma KEK, Ibaraki, Japan M. Patecki Warsaw University of Technology, Warsaw, Poland T. Tauchi, N. Terunuma Sokendai, Ibaraki, Japan
	A nanometer beam size in the interaction point (IP) is required in case of future linear colliders for achieving the desired rate of particle collisions. KEK Accelerator Test Facility (ATF2), a scaled down implementation of the beam delivery system (BDS), serves for investigating the limits of electron beam focusing at the interaction point. The goal of the ultra-low beta∗ study is to lower the IP vertical beam size by lowering the beta_y∗ value while keeping the beta_x∗ value unchanged. Good control over the beam optics is therefore required. The first experience with low beta∗ optics revealed a mismatch between the optics designed in the model with respect to the beam parameters observed in the experiment. Additionally, existing methods of beam parameters characterization at the IP were biased with high uncertainties making it difficult to set the desired optics. In this paper we report on the new method introduced in ATF2 for IP beam parameters characterization which gives a good control over the applied optics and makes the ultra-low beta∗ study possible to conduct. It can be also used for verifying the performance of some of the existing beam instrumentation devices.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB043
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THPMR045	CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization	3500
	F. Plassard, D. Schulte, R. Tomás CERN, Geneva, Switzerland P. Bambade LAL, Orsay, France
	This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR045
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Paper

Title

Page

Intra-beam IP Feedback Studies for the 380 GeV CLIC Beam Delivery System

2683

R.M. Bodenstein, P. Burrows, J. Snuverink
JAI, Egham, Surrey, United Kingdom
F. Plassard
CERN, Geneva, Switzerland

In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR009

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPMB043

Progress in Ultra-Low β* Study at ATF2

3335

M. Patecki, D.R. Bett, F. Plassard, R. Tomás
CERN, Geneva, Switzerland
K. Kubo, S. Kuroda, T. Naito, T. Okugi, T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan
M. Patecki
Warsaw University of Technology, Warsaw, Poland
T. Tauchi, N. Terunuma
Sokendai, Ibaraki, Japan

A nanometer beam size in the interaction point (IP) is required in case of future linear colliders for achieving the desired rate of particle collisions. KEK Accelerator Test Facility (ATF2), a scaled down implementation of the beam delivery system (BDS), serves for investigating the limits of electron beam focusing at the interaction point. The goal of the ultra-low beta∗ study is to lower the IP vertical beam size by lowering the beta_y∗ value while keeping the beta_x∗ value unchanged. Good control over the beam optics is therefore required. The first experience with low beta∗ optics revealed a mismatch between the optics designed in the model with respect to the beam parameters observed in the experiment. Additionally, existing methods of beam parameters characterization at the IP were biased with high uncertainties making it difficult to set the desired optics. In this paper we report on the new method introduced in ATF2 for IP beam parameters characterization which gives a good control over the applied optics and makes the ultra-low beta∗ study possible to conduct. It can be also used for verifying the performance of some of the existing beam instrumentation devices.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB043

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THPMR045

CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization

3500

F. Plassard, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
P. Bambade
LAL, Orsay, France

This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMR045

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