IPAC2017 - Classification: 01 Circular and Linear Colliders / A03 Linear Colliders

Paper	Title	Page
TUZB1	Final Results From the Clic Test Facility (CTF3)	1269
	R. Corsini CERN, Geneva, Switzerland
	The unique CLIC TEST Facility (CTF3) has been built more than a decade ago to demonstrate the feasibility of the CLIC two beam acceleration scheme. The emphasis was one the high current drive beam generation using a fully loaded highly efficient linac and a complex combination scheme to increase beam current and bunch repetition frequency. This drive beam has been used for deceleration experiments and two beam acceleration. A wealth of relevant results for accelerator physics even beyond CLIC has been obtained and will be presented. The rf to beam efficiency of the linac exceeds 95%, after combination the 28 A drive beam with 12 GHz bunch repetition rate has been used to extract more than 50% of its energy producing 1.3 GW of 12 GHz power as well as performing two beam acceleration at 12 GHz with gradients up to 150 MV/m.
	Slides TUZB1 [23.702 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUZB1
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB001	Proof of Concept of CLIC Final Focus Quadrupoles Stabilization	1290
	G. Balik, B. Aimard, L. Brunetti IN2P3-LAPP, Annecy-le-Vieux, France B. Caron SYMME, Annecy-le-Vieux, France
	The Compact LInear Collider (CLIC) [1] luminosity requires extremely low beam emittances. Therefore, high beam position stability is needed to provide cen-tral collisions of the opposing bunches. Since ground motion (GM) amplitudes are likely to be larger than the required tolerances, an Active Vibration Control (AVC) system is required to damp quadrupole motion to the desired value of 0.2 nm RMS at 4 Hz. This paper focuses on the vertical final focus quadrupoles (QD0, QF1) stabilization and demonstrates its feasibility. An AVC system to be installed under QD0 and QF1 has been developed and successfully tested at LAPP. Based on a dedicated homemade sensor with an ex-tremely low internal noise level of 0.05 nm at 4 Hz, it damps GM in the frequency range [3;70] Hz by up to 30 dB, leading to RMS values of approximately 0.25 nm at 4 Hz. Simulations based on GM measured in the Compact Muon Solenoid (CMS) experimental hall [2] show that with such a GM level, the specifications would only be achieved with a Passive Insulation (PI) system, which would filter ground motion starting at ~ 25 Hz
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB002	Material Tests for the ILC Positron Source	1293
	A. Ushakov, G.A. Moortgat-Pick University of Hamburg, Hamburg, Germany K. Aulenbacher, Th. Beiser, P. Heil, V. Tioukine IKP, Mainz, Germany A. Ignatenko, S. Riemann DESY Zeuthen, Zeuthen, Germany A.L. Prudnikava, Y. Tamashevich University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	The positron source is a vital system of the ILC. The conversion target that yields 10¹⁴ positrons per second will undergo high peak and cyclic load during ILC operation. In order to ensure stable long term operation of the positron source the candidate material for the conversion target has to be tested. The intense electron beam at the Mainz Microtron (MAMI) provides a good opportunity for such tests. The first results for Ti6Al4V are presented which is the candidate material for the positron conversion target as well as for the exit window to the photon beam absorber.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB006	Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC	1308
	Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori KEK, Ibaraki, Japan
	In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB016	The CLIC Main Linac Module Updated Design	1345
	C. Rossi, M. Aicheler, N. Catalán Lasheras, R. Corsini, S. Döbert, A. Grudiev, A. Latina, H. Mainaud Durand, M. Modena, H. Schmickler, D. Schulte, S. Stapnes, I. Syratchev, A.L. Vamvakas, W. Wuensch CERN, Geneva, Switzerland M. Aicheler HIP, University of Helsinki, Finland
	In 2016, CLIC implementation working groups have started their reflection on how to finalize the CLIC design work in the different areas of the project, aiming for a technical design and an overall implementation plan for CLIC being available for the next European Strategy Update around 2019. One of the working groups has focused its attention on the Main Linac hardware, which has brought together the different competences of the study with the aim of producing an advanced set of specifications for the design, installation and operation of the CLIC module. As the fundamental unit for the construction of the Main Beam linac, the CLIC module needs to move from the existing prototypes exploring its performance into an advanced and functional unit where the full life cycle of the module is considered. The progress of the working group activity is summarized in this paper, with considerations on the requirements for the design of the next-phase CLIC module.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB016
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB017	Results of the Beam-Loading Breakdown Rate Experiment at the CLIC Test Facility CTF3	1348
	E. Senes, T. Argyropoulos, N. Catalán Lasheras, R. Corsini, D. Gamba, J. Giner Navarro, A. Grudiev, G. McMonagle, R. Rajamaki, X.F.D. Stragier, I. Syratchev, F. Tecker, W. Wuensch CERN, Geneva, Switzerland J. Giner Navarro IFIC, Valencia, Spain R. Rajamaki Aalto University, School of Science and Technology, Aalto, Finland E. Senes Torino University, Torino, Italy
	The RF breakdown rate is crucial for the luminosity performance of the CLIC linear collider. The required breakdown rate at the design gradient of 100 MV/m has been demonstrated, without beam presence, in a number of 12 GHz CLIC prototype structures. Nevertheless, the beam-loading at CLIC significantly changes the field profile inside the structures, and the behaviour with beam needs to be understood. A dedicated experiment in the CLIC Test Facility CTF3 to determine the effect of beam on the breakdown rate has been collecting breakdown data throughout the year 2016. The complete results of the experiment and the effect of the beam-loading on the breakdown rate are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK075	ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs	1864
	N. Fuster-Martínez, A. Faus-Golfe IFIC, Valencia, Spain P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang LAL, Orsay, France K. Kubo, T. Okugi, T. Tauchi, N. Terunuma Sokendai, Ibaraki, Japan S. Kuroda KEK, Ibaraki, Japan I. Podadera, F. Toral CIEMAT, Madrid, Spain G.R. White SLAC, Menlo Park, California, USA
	A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK075
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK099	Beam-Based Alignment for the Rebaselining of CLIC RTML	1939
	Y. Han, L. Ma SDU, Shandong, People's Republic of China A. Latina, D. Schulte CERN, Geneva, Switzerland
	The first stage of the CLIC is proposed to be at 380 GeV. So the Ring To Main Linac (RTML), which transport the beams from the damping ring to main linac with minimal emittance growth, should be restudied due to the new beam properties. In this paper the two bunch compressors in the RTML are redesigned. Then a complete study of the static beam-based alignment techniques along RTML is presented. The beam-based correction includes one-to-one and dispersion-free steering, then a global correction using tuning bumps is applied to reduce the final emittance and mitigate the effects of coupling. The results showed that the emittance growth budgets can be met both in the horizontal and vertical planes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK099
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPVA130	CLIC Tuning Performance Under Realistic Error Conditions	2403
	E. Marín, A. Latina, F. Plassard, D. Schulte, R. Tomás CERN, Geneva, Switzerland
	In this paper we present the latest results regarding the tuning study of the baseline design of the CLIC Final Focus System. In previous studies, 90% of the machines reach 90% of the nominal luminosity, when considering beam position monitor errors and transverse misalignments of magnets for a single beam case. In the present study, roll misalignments and strength errors are also included for both e^- and e⁺ beamlines, making the study a more realistic one. First, second and third order knobs are implemented in the tuning procedure to target the most relevant beam size aberrations. In order to minimise the total number of luminosity measurements a simultaneous scan of various knobs has been developed to cope with the non-fully orthogonality of the knobs. The obtained results for single and double beam studies are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA130
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Final Results From the Clic Test Facility (CTF3)

1269

R. Corsini
CERN, Geneva, Switzerland

The unique CLIC TEST Facility (CTF3) has been built more than a decade ago to demonstrate the feasibility of the CLIC two beam acceleration scheme. The emphasis was one the high current drive beam generation using a fully loaded highly efficient linac and a complex combination scheme to increase beam current and bunch repetition frequency. This drive beam has been used for deceleration experiments and two beam acceleration. A wealth of relevant results for accelerator physics even beyond CLIC has been obtained and will be presented. The rf to beam efficiency of the linac exceeds 95%, after combination the 28 A drive beam with 12 GHz bunch repetition rate has been used to extract more than 50% of its energy producing 1.3 GW of 12 GHz power as well as performing two beam acceleration at 12 GHz with gradients up to 150 MV/m.

Slides TUZB1 [23.702 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUZB1

Export •

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

TUPAB001

Proof of Concept of CLIC Final Focus Quadrupoles Stabilization

1290

G. Balik, B. Aimard, L. Brunetti
IN2P3-LAPP, Annecy-le-Vieux, France
B. Caron
SYMME, Annecy-le-Vieux, France

The Compact LInear Collider (CLIC) [1] luminosity requires extremely low beam emittances. Therefore, high beam position stability is needed to provide cen-tral collisions of the opposing bunches. Since ground motion (GM) amplitudes are likely to be larger than the required tolerances, an Active Vibration Control (AVC) system is required to damp quadrupole motion to the desired value of 0.2 nm RMS at 4 Hz. This paper focuses on the vertical final focus quadrupoles (QD0, QF1) stabilization and demonstrates its feasibility. An AVC system to be installed under QD0 and QF1 has been developed and successfully tested at LAPP. Based on a dedicated homemade sensor with an ex-tremely low internal noise level of 0.05 nm at 4 Hz, it damps GM in the frequency range [3;70] Hz by up to 30 dB, leading to RMS values of approximately 0.25 nm at 4 Hz. Simulations based on GM measured in the Compact Muon Solenoid (CMS) experimental hall [2] show that with such a GM level, the specifications would only be achieved with a Passive Insulation (PI) system, which would filter ground motion starting at ~ 25 Hz

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB001

Export •

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

TUPAB002

Material Tests for the ILC Positron Source

1293

A. Ushakov, G.A. Moortgat-Pick
University of Hamburg, Hamburg, Germany
K. Aulenbacher, Th. Beiser, P. Heil, V. Tioukine
IKP, Mainz, Germany
A. Ignatenko, S. Riemann
DESY Zeuthen, Zeuthen, Germany
A.L. Prudnikava, Y. Tamashevich
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

The positron source is a vital system of the ILC. The conversion target that yields 10¹⁴ positrons per second will undergo high peak and cyclic load during ILC operation. In order to ensure stable long term operation of the positron source the candidate material for the conversion target has to be tested. The intense electron beam at the Mainz Microtron (MAMI) provides a good opportunity for such tests. The first results for Ti6Al4V are presented which is the candidate material for the positron conversion target as well as for the exit window to the photon beam absorber.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB002

Export •

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

TUPAB006

Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC

1308

Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori
KEK, Ibaraki, Japan

In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB006

Export •

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

TUPAB016

The CLIC Main Linac Module Updated Design

1345

C. Rossi, M. Aicheler, N. Catalán Lasheras, R. Corsini, S. Döbert, A. Grudiev, A. Latina, H. Mainaud Durand, M. Modena, H. Schmickler, D. Schulte, S. Stapnes, I. Syratchev, A.L. Vamvakas, W. Wuensch
CERN, Geneva, Switzerland
M. Aicheler
HIP, University of Helsinki, Finland

In 2016, CLIC implementation working groups have started their reflection on how to finalize the CLIC design work in the different areas of the project, aiming for a technical design and an overall implementation plan for CLIC being available for the next European Strategy Update around 2019. One of the working groups has focused its attention on the Main Linac hardware, which has brought together the different competences of the study with the aim of producing an advanced set of specifications for the design, installation and operation of the CLIC module. As the fundamental unit for the construction of the Main Beam linac, the CLIC module needs to move from the existing prototypes exploring its performance into an advanced and functional unit where the full life cycle of the module is considered. The progress of the working group activity is summarized in this paper, with considerations on the requirements for the design of the next-phase CLIC module.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB016

Export •

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

TUPAB017

Results of the Beam-Loading Breakdown Rate Experiment at the CLIC Test Facility CTF3

1348

E. Senes, T. Argyropoulos, N. Catalán Lasheras, R. Corsini, D. Gamba, J. Giner Navarro, A. Grudiev, G. McMonagle, R. Rajamaki, X.F.D. Stragier, I. Syratchev, F. Tecker, W. Wuensch
CERN, Geneva, Switzerland
J. Giner Navarro
IFIC, Valencia, Spain
R. Rajamaki
Aalto University, School of Science and Technology, Aalto, Finland
E. Senes
Torino University, Torino, Italy

The RF breakdown rate is crucial for the luminosity performance of the CLIC linear collider. The required breakdown rate at the design gradient of 100 MV/m has been demonstrated, without beam presence, in a number of 12 GHz CLIC prototype structures. Nevertheless, the beam-loading at CLIC significantly changes the field profile inside the structures, and the behaviour with beam needs to be understood. A dedicated experiment in the CLIC Test Facility CTF3 to determine the effect of beam on the breakdown rate has been collecting breakdown data throughout the year 2016. The complete results of the experiment and the effect of the beam-loading on the breakdown rate are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB017

Export •

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

TUPIK075

ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs

1864

N. Fuster-Martínez, A. Faus-Golfe
IFIC, Valencia, Spain
P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang
LAL, Orsay, France
K. Kubo, T. Okugi, T. Tauchi, N. Terunuma
Sokendai, Ibaraki, Japan
S. Kuroda
KEK, Ibaraki, Japan
I. Podadera, F. Toral
CIEMAT, Madrid, Spain
G.R. White
SLAC, Menlo Park, California, USA

A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK075

Export •

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

TUPIK099

Beam-Based Alignment for the Rebaselining of CLIC RTML

1939

Y. Han, L. Ma
SDU, Shandong, People's Republic of China
A. Latina, D. Schulte
CERN, Geneva, Switzerland

The first stage of the CLIC is proposed to be at 380 GeV. So the Ring To Main Linac (RTML), which transport the beams from the damping ring to main linac with minimal emittance growth, should be restudied due to the new beam properties. In this paper the two bunch compressors in the RTML are redesigned. Then a complete study of the static beam-based alignment techniques along RTML is presented. The beam-based correction includes one-to-one and dispersion-free steering, then a global correction using tuning bumps is applied to reduce the final emittance and mitigate the effects of coupling. The results showed that the emittance growth budgets can be met both in the horizontal and vertical planes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK099

Export •

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

TUPVA130

CLIC Tuning Performance Under Realistic Error Conditions

2403

E. Marín, A. Latina, F. Plassard, D. Schulte, R. Tomás
CERN, Geneva, Switzerland

In this paper we present the latest results regarding the tuning study of the baseline design of the CLIC Final Focus System. In previous studies, 90% of the machines reach 90% of the nominal luminosity, when considering beam position monitor errors and transverse misalignments of magnets for a single beam case. In the present study, roll misalignments and strength errors are also included for both e^- and e⁺ beamlines, making the study a more realistic one. First, second and third order knobs are implemented in the tuning procedure to target the most relevant beam size aberrations. In order to minimise the total number of luminosity measurements a simultaneous scan of various knobs has been developed to cope with the non-fully orthogonality of the knobs. The obtained results for single and double beam studies are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA130

Export •

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