IPAC2011 - List of Keywords (linear-collider)

Paper	Title	Other Keywords	Page
MOYBA01	Present Status of the ILC Project and Developments	cavity, linac, collider, electron	16
	M.C. Ross Fermilab, Batavia, USA N.J. Walker DESY, Hamburg, Germany A. Yamamoto KEK, Ibaraki, Japan
	Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The Technical Design of the ILC Project will be finished in late 2012. The Technical Design Report will include a description of the updated design, with a cost estimate and a project plan, and the results of R & D done in support of the ILC. Results from directed ILC R & D are used to reduce the cost and risk associated with the ILC design. We present a summary of key challenges and show how the global R & D effort has addressed them. The most important activity has been in pursuit of very high gradient superconducting RF linac technology. There has been excellent progress toward the goal of practical industrial production of niobium sheet-metal cavities with gradient performance in excess of 35 MV/m. In addition, three purpose-built beam test facilities have been constructed and used to study and demonstrate high current linac performance, electron-cloud beam dynamics and precision beam control. The report also includes a summary of component design studies and conventional facilities cost optimization design studies.
	Slides MOYBA01 [9.755 MB]

MOPC119	Fastest Electropolishing Technique on Niobium for Particle Accelerators*	cavity, SRF, cathode, niobium	358
	A.T. Wu, S. Jin, R.A. Rimmer JLAB, Newport News, Virginia, USA X.Y. Lu, K. Zhao PKU/IHIP, Beijing, People's Republic of China
	Funding: The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes. Field emission on the inner surfaces of niobium (Nb) superconducting radio frequency (SRF) cavities is still one of the major obstacles for reaching high accelerating gradients for SRF community. Our previous experimental results [1] seemed to imply that the threshold of field emission was related to the thickness of Nb surface oxide layers. In this contribution, a more detailed study on the influences of the surface oxide layers on the field emission on Nb surfaces will be reported. By anodization technique, the thickness of the surface pentoxide layer was artificially fabricated from 3nm up to 460nm. A home-made scanning field emission microscope (SFEM) was employed to perform the scans on the surfaces. Emitters were characterized using a scanning electron microscope together with an energy dispersive x-ray analyzer. The experimental results could be understood by a simple model calculation based on classic electromagnetic theory as shown in Ref.1. Possibly implications for Nb SRF cavity applications from this study will be discussed. Authored by The Southeastern Universities Research Association, Inc. under U.S. DOE Contract No. DE-AC05-84ER40150.

MOPC142	25 Year Performance Review of the SLAC 5045 S-Band Klystron	klystron, high-voltage, cathode, linac	409
	A. Jensen, A.S. Beebe, M.V. Fazio, A.A. Haase, E.N. Jongewaard, C. Pearson, D.W. Sprehn, A.E. Vlieks, L.E. Whicker SLAC, Menlo Park, California, USA
	Funding: This work was supported by the U.S. Department of Energy under contract DE-AC03-76SF00515. The SLAC 5045 S-band klystron has proven to be a remarkably reliable high peak power tube. Originally developed in the 1980’s as an upgraded RF power source for the Stanford Linear Collider, it has continually powered the SLAC linac in support of numerous programs in particle physics and photon science. The large number of tubes built and operated (more than 800) coupled with accumulated running statistics over the last 25+ years represents an unprecedented wealth of operational experience for high pulse power klystrons in accelerator applications. Mean time between failures has continued to rise during this period and is frequently in excess of 100,000 hours during the last several years. Lifetime statistics as well as some important failure modes are presented and examined here.

MOPO017	Latest Performance Results from the FONT5 Intra-train Position and Angle Feedback System at ATF2	feedback, kicker, collider, positron	520
	G.B. Christian, D.R. Bett, M.R. Davis, C. Perry JAI, Oxford, United Kingdom R. Apsimon, P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom B. Constance, A. Gerbershagen CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch timescales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. An overview of the hardware, and the latest results from beam tests at ATF2, will be presented. A total system latency as low as approximately 140 ns has been demonstrated.

TUPC002	Study of a Large Piwinski’s Angle Configuration for Linear Colliders	luminosity, collider, radiation, background	988
	R. Versteegen, O. Napoly CEA/DSM/IRFU, France
	The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC005	Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider	target, photon, positron, collider	994
	O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva University of Hamburg, Hamburg, Germany A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov DESY, Hamburg, Germany A. Schälicke, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC134	Phase Detection Electronics for CLIC	pick-up, controls, linac, luminosity	1338
	A. Andersson CERN, Geneva, Switzerland
	The Compact Linear Collider (CLIC) requires very tight RF phase synchronisation in order to preserve high luminosity. The electronics required for processing the signals delivered from the phase pick-ups present a significant challenge. This paper discusses the strategy adopted to achieve a sufficiently accurate measurement of the phase. Performance measurements performed in the lab of some of the sub-systems are also presented.

TUPC164	Position Determination of Closely Spaced Bunches using Cavity BPMs	cavity, single-bunch, quadrupole, collider	1419
	N.Y. Joshi, S.T. Boogert, F.J. Cullinan, A. Lyapin JAI, Egham, Surrey, United Kingdom
	Cavity Beam Position Monitor (BPM) systems with high-Q form a major part of precision position measurement diagnostics for linear accelerators with low emittance beam. Using cavity BPMs, the position resolution of less than 100 nm has been demonstrated in single bunch mode operation. In the case of closely spaced bunches, where the decay time of the cavity is comparable to the time separation between bunches, the BPM signal from a bunch is polluted by the signal induced from the previous bunches in the same bunch-train. This paper discuss our ongoing work to develop the methods to extract the position of the closely spaced bunches using cavity BPMs. A signal subtraction code is being developed to remove the signal pollution from previous bunches and to determine the individual bunch position. Another code has been developed to simulate the BPM data for the cross check. Performance of the code is studied on the experimental and simulated data. Application of the analysis techniques to the linear colliders, such as International Linear Collider (ILC) and Compact LInear Collider (CLIC), are briefly discussed.

TUPS055	Organizing the ILC Technical Design Documentation	lattice, positron, damping, collider	1656
	L. Hagge, S. Eucker, B. List, N.J. Walker, N. Welle DESY, Hamburg, Germany
	The Global Design Effort (GDE) for the International Linear Collider (ILC) is currently preparing the Technical Design Report (TDR), which will be released at the end of 2012 and will serve as the basis for a decision process. The TDR will be written based on the Technical Design Documentation (TDD), which captures the entire design efforts, results and rationale, including e. g. parameter lists, specifications, CAD models and drawings, cost estimation, simulations and calculations, and summary reports. Formal review meetings help making the documentation complete, correct and consistent. The TDD is stored in an Engineering Data Management System (EDMS), which ensures that it remains accessible beyond the GDE in an organized way and at a well-defined location. The EDMS provides traceability (e. g. from design decisions to corresponding cost estimates), version management and change control. The poster presents the process and tools that were established for the organization of the TDD and provides an overview of the emerging documentation.

TUPS081	3D Visualization, Simulation and Virtual Reality in Accelerator Development	simulation, collider, site	1728
	L. Hagge, A. Herz, J. Kreutzkamp, S. Lang, V. Rupprecht, S. Sühl, N. Welle DESY, Hamburg, Germany
	Visualizing complex beamline designs, animating installation procedures and virtually walking through planned facilities - 3D modelling is a powerful tool with a broad range of applications in accelerator development. The poster describes established and emerging 3D modelling applications at the European XFEL and their benefits: 3D visualization enables inspection and compliance analysis of interfacing systems and components. Simulations enable early verification of e.g. safety and transportation concepts. Digital humans can be inserted into accelerator models to perform e.g. reachability and field-of-sight studies for installation works. Movies of transport and installation procedures can be created for staff training. And ultimately, stereo projection can be used to inspect and simulate designs and processes in virtual environments. 3D modelling helps discovering and resolving design issues earlier and leads to large savings in time and cost.

TUPS099	A Study of the Surface Quality of High Purity Copper after Heat Treatment	vacuum, electron, damping, collider	1771
	M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin CERN, Geneva, Switzerland
	The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

Paper

Title

Other Keywords

Page

MOYBA01

Present Status of the ILC Project and Developments

cavity, linac, collider, electron

16

M.C. Ross
Fermilab, Batavia, USA
N.J. Walker
DESY, Hamburg, Germany
A. Yamamoto
KEK, Ibaraki, Japan

Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The Technical Design of the ILC Project will be finished in late 2012. The Technical Design Report will include a description of the updated design, with a cost estimate and a project plan, and the results of R & D done in support of the ILC. Results from directed ILC R & D are used to reduce the cost and risk associated with the ILC design. We present a summary of key challenges and show how the global R & D effort has addressed them. The most important activity has been in pursuit of very high gradient superconducting RF linac technology. There has been excellent progress toward the goal of practical industrial production of niobium sheet-metal cavities with gradient performance in excess of 35 MV/m. In addition, three purpose-built beam test facilities have been constructed and used to study and demonstrate high current linac performance, electron-cloud beam dynamics and precision beam control. The report also includes a summary of component design studies and conventional facilities cost optimization design studies.

Slides MOYBA01 [9.755 MB]

MOPC119

Fastest Electropolishing Technique on Niobium for Particle Accelerators*

cavity, SRF, cathode, niobium

358

A.T. Wu, S. Jin, R.A. Rimmer
JLAB, Newport News, Virginia, USA
X.Y. Lu, K. Zhao
PKU/IHIP, Beijing, People's Republic of China

Funding: The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.
Field emission on the inner surfaces of niobium (Nb) superconducting radio frequency (SRF) cavities is still one of the major obstacles for reaching high accelerating gradients for SRF community. Our previous experimental results [1] seemed to imply that the threshold of field emission was related to the thickness of Nb surface oxide layers. In this contribution, a more detailed study on the influences of the surface oxide layers on the field emission on Nb surfaces will be reported. By anodization technique, the thickness of the surface pentoxide layer was artificially fabricated from 3nm up to 460nm. A home-made scanning field emission microscope (SFEM) was employed to perform the scans on the surfaces. Emitters were characterized using a scanning electron microscope together with an energy dispersive x-ray analyzer. The experimental results could be understood by a simple model calculation based on classic electromagnetic theory as shown in Ref.1. Possibly implications for Nb SRF cavity applications from this study will be discussed.
Authored by The Southeastern Universities Research Association, Inc. under U.S. DOE Contract No. DE-AC05-84ER40150.

MOPC142

25 Year Performance Review of the SLAC 5045 S-Band Klystron

klystron, high-voltage, cathode, linac

409

A. Jensen, A.S. Beebe, M.V. Fazio, A.A. Haase, E.N. Jongewaard, C. Pearson, D.W. Sprehn, A.E. Vlieks, L.E. Whicker
SLAC, Menlo Park, California, USA

Funding: This work was supported by the U.S. Department of Energy under contract DE-AC03-76SF00515.
The SLAC 5045 S-band klystron has proven to be a remarkably reliable high peak power tube. Originally developed in the 1980’s as an upgraded RF power source for the Stanford Linear Collider, it has continually powered the SLAC linac in support of numerous programs in particle physics and photon science. The large number of tubes built and operated (more than 800) coupled with accumulated running statistics over the last 25+ years represents an unprecedented wealth of operational experience for high pulse power klystrons in accelerator applications. Mean time between failures has continued to rise during this period and is frequently in excess of 100,000 hours during the last several years. Lifetime statistics as well as some important failure modes are presented and examined here.

MOPO017

Latest Performance Results from the FONT5 Intra-train Position and Angle Feedback System at ATF2

feedback, kicker, collider, positron

520

G.B. Christian, D.R. Bett, M.R. Davis, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
B. Constance, A. Gerbershagen
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch timescales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. An overview of the hardware, and the latest results from beam tests at ATF2, will be presented. A total system latency as low as approximately 140 ns has been demonstrated.

TUPC002

Study of a Large Piwinski’s Angle Configuration for Linear Colliders

luminosity, collider, radiation, background

988

R. Versteegen, O. Napoly
CEA/DSM/IRFU, France

The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC005

Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider

target, photon, positron, collider

994

O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva
University of Hamburg, Hamburg, Germany
A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov
DESY, Hamburg, Germany
A. Schälicke, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC134

Phase Detection Electronics for CLIC

pick-up, controls, linac, luminosity

1338

A. Andersson
CERN, Geneva, Switzerland

The Compact Linear Collider (CLIC) requires very tight RF phase synchronisation in order to preserve high luminosity. The electronics required for processing the signals delivered from the phase pick-ups present a significant challenge. This paper discusses the strategy adopted to achieve a sufficiently accurate measurement of the phase. Performance measurements performed in the lab of some of the sub-systems are also presented.

TUPC164

Position Determination of Closely Spaced Bunches using Cavity BPMs

cavity, single-bunch, quadrupole, collider

1419

N.Y. Joshi, S.T. Boogert, F.J. Cullinan, A. Lyapin
JAI, Egham, Surrey, United Kingdom

Cavity Beam Position Monitor (BPM) systems with high-Q form a major part of precision position measurement diagnostics for linear accelerators with low emittance beam. Using cavity BPMs, the position resolution of less than 100 nm has been demonstrated in single bunch mode operation. In the case of closely spaced bunches, where the decay time of the cavity is comparable to the time separation between bunches, the BPM signal from a bunch is polluted by the signal induced from the previous bunches in the same bunch-train. This paper discuss our ongoing work to develop the methods to extract the position of the closely spaced bunches using cavity BPMs. A signal subtraction code is being developed to remove the signal pollution from previous bunches and to determine the individual bunch position. Another code has been developed to simulate the BPM data for the cross check. Performance of the code is studied on the experimental and simulated data. Application of the analysis techniques to the linear colliders, such as International Linear Collider (ILC) and Compact LInear Collider (CLIC), are briefly discussed.

TUPS055

Organizing the ILC Technical Design Documentation

lattice, positron, damping, collider

1656

L. Hagge, S. Eucker, B. List, N.J. Walker, N. Welle
DESY, Hamburg, Germany

The Global Design Effort (GDE) for the International Linear Collider (ILC) is currently preparing the Technical Design Report (TDR), which will be released at the end of 2012 and will serve as the basis for a decision process. The TDR will be written based on the Technical Design Documentation (TDD), which captures the entire design efforts, results and rationale, including e. g. parameter lists, specifications, CAD models and drawings, cost estimation, simulations and calculations, and summary reports. Formal review meetings help making the documentation complete, correct and consistent. The TDD is stored in an Engineering Data Management System (EDMS), which ensures that it remains accessible beyond the GDE in an organized way and at a well-defined location. The EDMS provides traceability (e. g. from design decisions to corresponding cost estimates), version management and change control. The poster presents the process and tools that were established for the organization of the TDD and provides an overview of the emerging documentation.

TUPS081

3D Visualization, Simulation and Virtual Reality in Accelerator Development

simulation, collider, site

1728

L. Hagge, A. Herz, J. Kreutzkamp, S. Lang, V. Rupprecht, S. Sühl, N. Welle
DESY, Hamburg, Germany

Visualizing complex beamline designs, animating installation procedures and virtually walking through planned facilities - 3D modelling is a powerful tool with a broad range of applications in accelerator development. The poster describes established and emerging 3D modelling applications at the European XFEL and their benefits: 3D visualization enables inspection and compliance analysis of interfacing systems and components. Simulations enable early verification of e.g. safety and transportation concepts. Digital humans can be inserted into accelerator models to perform e.g. reachability and field-of-sight studies for installation works. Movies of transport and installation procedures can be created for staff training. And ultimately, stereo projection can be used to inspect and simulate designs and processes in virtual environments. 3D modelling helps discovering and resolving design issues earlier and leads to large savings in time and cost.

TUPS099

A Study of the Surface Quality of High Purity Copper after Heat Treatment

vacuum, electron, damping, collider

1771

M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin
CERN, Geneva, Switzerland

The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.