HB2023 - List of Keywords (acceleration)

Paper	Title	Other Keywords	Page
WEA2C1	Tune Optimization for Alleviating Space Charge Effects and Suppressing Beam Instability in the RCS of CSNS	space-charge, resonance, ECR, simulation	228
	S.Y. Xu, L. Huang, M.Y. Huang, Y. Li, S. Wang IHEP, Beijing, People’s Republic of China
	The design betatron tune of the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) is (4.86, 4.80), which allows for incoherent tune shifts to avoid serious systematic betatron resonances. When the operational bare tune was set at the design value, serious beam instability in the horizontal plane and beam loss induced by half-integer resonance in the vertical plane under space charge detuning were observed. The tunes over the whole acceleration process are optimized based on space charge effects and beam instability. In the RCS, manipulating the tune during the beam acceleration process is a challenge due to the quadrupole magnets being powered by resonant circuits. In the RCS of CSNS, a method of waveform compensation for RCS magnets was investigated to accurately manipulate the magnetic field ramping process. The optimized tune pattern was able to well control the beam loss induced by space charge and beam instability. The beam power of CSNS achieved the design value of 100 kW with small uncontrolled beam loss.
	Slides WEA2C1 [4.710 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2C1
About •	Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEA3I1	Synchronous Phases and Transit Time Factor	cavity, linac, accelerating-gradient, focusing	241
	J.-M. Lagniel GANIL, Caen, France
	Synchronous phases (¿s) and transit time factors (T) are THE key parameters for linac designs and operations. While the couple (¿s, T) is still our way of thinking the longitudinal beam dynamics, it is important to have in mind that the original ¿Panofsky¿ definition of these parameters is no longer valid in the case of high accelerating gradients leading to high particle velocity changes and in the case of multi-gap cavities. In this case, a new (¿s, T) definition allowing to keep both acceleration and longitudinal focusing properties is proposed. Examples are given in the SPIRAL2 linac case.
	Slides WEA3I1 [2.369 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA3I1
About •	Received ※ 27 September 2023 — Revised ※ 12 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 17 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEC3C1	Beyond 1-MW Scenario in J-Parc Rapid-Cycling Synchrotron	cavity, operation, linac, injection	270
	K. Yamamoto, T. Morishita, K. Moriya, H. Okita, P.K. Saha, Y. Shobuda, F. Tamura, I. Yamada, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The 3-GeV rapid cycling synchrotron at the Ja-pan Pro-ton Accelerator Research Complex was designed to provid 1-MW proton beams to the Material and Life Sci-ence Experimental Facility and Main Ring. Thanks to the improvement works of the accelerator system, we success-fully accelerate 1-MW beam with quite small beam loss. Currently, the beam power of RCS is limited by the lack of anode current in the RF cavity system rather than the beam loss. Recently we developed a new acceleration cavity that can accelerate a beam with less anode current. This new cavity enables us not only to reduce require-ment of the anode power supply but also to accelerate more than 1-MW beam. We have started to consider the way to achieve beyond 1-MW beam acceleration. So far, it is expected that up to 1.5-MW beam can be accelerated after replacement of the RF cavity. We have also contin-ued study to achieve more than 2 MW beam in J-PARC RCS.
	Slides WEC3C1 [2.787 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3C1
About •	Received ※ 25 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 26 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEC4I1	RF Systems of J-PARC Proton Synchrotrons for High-Intensity Longitudinal Beam Optimization and Handling	cavity, feedback, operation, controls	305
	F. Tamura, R. Miyakoshi, M. Nomura, H. Okita, T. Shimada, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan K. Hara, K. Hasegawa, C. Ohmori, K. Seiya, Y. Sugiyama, M. Yoshii KEK, Tokai, Ibaraki, Japan
	The application of magnetic alloy (MA) cores to the accelerating rf cavities in high intensity proton synchrotrons was pioneered for the J-PARC synchrotrons, the RCS and MR. The MA loaded cavities can generate high accelerating voltages. The wideband frequency response of the MA cavity enables the frequency sweep to follow the velocity change of protons without the tuning loop. The dual harmonic operation, where a single cavity is driven by the superposition of the fundamental and second harmonic rf voltages, is indispensable for the longitudinal bunch shaping to alleviate the space charge effects in the RCS. These advantages of the MA cavity are also disadvantages when looking at them from a different perspective. Since the wake voltage consists of several harmonics, which can cause bucket distortion or coupled-bunch instabilities, the beam loading compensation must be multiharmonic. The operation of tubes in the final stage amplifier is not trivial when accelerating very high intensity beams; the output current is high and the anode voltageis also multiharmonic. We summarize our effort against these issues in the operation of the RCS and MR for more than 10 years.
	Slides WEC4I1 [6.932 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC4I1
About •	Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 29 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP43	Intensity Effects in a Chain of Muon RCSs	HOM, cavity, wakefield, collider	579
	F. Batsch, D. Amorim, H. Damerau, A. Grudiev, I. Karpov, E. Métral, D. Schulte CERN, Meyrin, Switzerland A. Chancé CEA, Gif-sur-Yvette, France S. Udongwo Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Funded by the European Union under Grant Agreement n.101094300 The muon collider offers an attractive path to a compact, multi-TeV lepton collider. However, the short muon lifetime leads to stringent requirements on the fast energy increase. While extreme energy gains in the order of several GeV per turn are crucial for a high elevated muon survival rate, ultra-short and intense bunches are needed to achieve large luminosity. The longitudinal beam dynamics of a chain of rapid cycling synchrotrons (RCS) for acceleration from around 60 GeV to several TeV is being investigated in the framework of the International Muon Collider Collaboration. Each RCS must have a distributed radio-frequency (RF) system with several hundred RF stations to establish stable synchrotron motion. In this contribution, the beam-induced voltage in each RCS is studied, assuming a single high-intensity bunch per beam in each direction and ILC-like 1.3 GHz accelerating structures. The impact of single- and multi-turn wakefields on longitudinal stability and RF power requirements is analysed with particle tracking simulations. Special attention is moreover paid to the beam power deposited into the higher-order modes of the RF cavities.
	Poster THBP43 [1.345 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP43
About •	Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBP55	Commissioning of NICA Injection Complex	booster, injection, electron, operation	618
	V.A. Lebedev, O.I. Brovko, A.V. Butenko, E.E. Donets, B.V. Golovenskiy, E.V. Gorbachev, S.A. Kostromin, K.A. Levterov, I.N. Meshkov, A.S. Sergeev, M.M. Shandov, A.O. Sidorin, V.L. Smirnov, E. Syresin, A. Tuzikov JINR, Dubna, Moscow Region, Russia I. Nikolaichuk, A.Yu. Ramsdorf JINR/VBLHEP, Dubna, Moscow region, Russia
	The Nuclotron-based Ion Collider fAcility (NICA) is under construction at JINR. The NICA project goal is to provide colliding beams for studies of collisions of heavy fully stripped ions and light p¿lairized ions. The NICA Collider includes two rings with 503 m circumference each and the injection complex. For the heavy ion mode, the injection complex consists of following accelerators: 3.2 MeV/u linac (HILAC), 600 MeV/u (A/Z=6) superconducting booster synchrotron (Booster) and main superconducting synchrotron (Nuclotron) with kinetic energy up to 3.9 GeV/u (A/Z=2.5). The injection complex has been under commissioning for more than 2 years. Its Run IV was carried from October 2022 to February of 2023. It was aimed on the injection complex preparation for the collider operations in the heavy ion mode. Additionally, the slowly extracted 3.9 GeV/u xenon beam was delivered to the BM&N experiment resulting in 250 million events in the detector. The paper discusses main results of the injection complex commissioning and plans for its further development. The beam commissioning of the collider is expected in the 2nd half of 2025.
DOI •	reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP55
About •	Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 17 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

WEA2C1

Tune Optimization for Alleviating Space Charge Effects and Suppressing Beam Instability in the RCS of CSNS

space-charge, resonance, ECR, simulation

228

S.Y. Xu, L. Huang, M.Y. Huang, Y. Li, S. Wang
IHEP, Beijing, People’s Republic of China

The design betatron tune of the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) is (4.86, 4.80), which allows for incoherent tune shifts to avoid serious systematic betatron resonances. When the operational bare tune was set at the design value, serious beam instability in the horizontal plane and beam loss induced by half-integer resonance in the vertical plane under space charge detuning were observed. The tunes over the whole acceleration process are optimized based on space charge effects and beam instability. In the RCS, manipulating the tune during the beam acceleration process is a challenge due to the quadrupole magnets being powered by resonant circuits. In the RCS of CSNS, a method of waveform compensation for RCS magnets was investigated to accurately manipulate the magnetic field ramping process. The optimized tune pattern was able to well control the beam loss induced by space charge and beam instability. The beam power of CSNS achieved the design value of 100 kW with small uncontrolled beam loss.

Slides WEA2C1 [4.710 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA2C1

About •

Received ※ 01 October 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 23 October 2023

Cite •

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

WEA3I1

Synchronous Phases and Transit Time Factor

cavity, linac, accelerating-gradient, focusing

241

J.-M. Lagniel
GANIL, Caen, France

Synchronous phases (¿s) and transit time factors (T) are THE key parameters for linac designs and operations. While the couple (¿s, T) is still our way of thinking the longitudinal beam dynamics, it is important to have in mind that the original ¿Panofsky¿ definition of these parameters is no longer valid in the case of high accelerating gradients leading to high particle velocity changes and in the case of multi-gap cavities. In this case, a new (¿s, T) definition allowing to keep both acceleration and longitudinal focusing properties is proposed. Examples are given in the SPIRAL2 linac case.

Slides WEA3I1 [2.369 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEA3I1

About •

Received ※ 27 September 2023 — Revised ※ 12 October 2023 — Accepted ※ 13 October 2023 — Issued ※ 17 October 2023

Cite •

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

WEC3C1

Beyond 1-MW Scenario in J-Parc Rapid-Cycling Synchrotron

cavity, operation, linac, injection

270

K. Yamamoto, T. Morishita, K. Moriya, H. Okita, P.K. Saha, Y. Shobuda, F. Tamura, I. Yamada, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The 3-GeV rapid cycling synchrotron at the Ja-pan Pro-ton Accelerator Research Complex was designed to provid 1-MW proton beams to the Material and Life Sci-ence Experimental Facility and Main Ring. Thanks to the improvement works of the accelerator system, we success-fully accelerate 1-MW beam with quite small beam loss. Currently, the beam power of RCS is limited by the lack of anode current in the RF cavity system rather than the beam loss. Recently we developed a new acceleration cavity that can accelerate a beam with less anode current. This new cavity enables us not only to reduce require-ment of the anode power supply but also to accelerate more than 1-MW beam. We have started to consider the way to achieve beyond 1-MW beam acceleration. So far, it is expected that up to 1.5-MW beam can be accelerated after replacement of the RF cavity. We have also contin-ued study to achieve more than 2 MW beam in J-PARC RCS.

Slides WEC3C1 [2.787 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC3C1

About •

Received ※ 25 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 26 October 2023

Cite •

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

WEC4I1

RF Systems of J-PARC Proton Synchrotrons for High-Intensity Longitudinal Beam Optimization and Handling

cavity, feedback, operation, controls

305

F. Tamura, R. Miyakoshi, M. Nomura, H. Okita, T. Shimada, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan
K. Hara, K. Hasegawa, C. Ohmori, K. Seiya, Y. Sugiyama, M. Yoshii
KEK, Tokai, Ibaraki, Japan

The application of magnetic alloy (MA) cores to the accelerating rf cavities in high intensity proton synchrotrons was pioneered for the J-PARC synchrotrons, the RCS and MR. The MA loaded cavities can generate high accelerating voltages. The wideband frequency response of the MA cavity enables the frequency sweep to follow the velocity change of protons without the tuning loop. The dual harmonic operation, where a single cavity is driven by the superposition of the fundamental and second harmonic rf voltages, is indispensable for the longitudinal bunch shaping to alleviate the space charge effects in the RCS. These advantages of the MA cavity are also disadvantages when looking at them from a different perspective. Since the wake voltage consists of several harmonics, which can cause bucket distortion or coupled-bunch instabilities, the beam loading compensation must be multiharmonic. The operation of tubes in the final stage amplifier is not trivial when accelerating very high intensity beams; the output current is high and the anode voltageis also multiharmonic. We summarize our effort against these issues in the operation of the RCS and MR for more than 10 years.

Slides WEC4I1 [6.932 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-WEC4I1

About •

Received ※ 29 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 29 October 2023

Cite •

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

THBP43

Intensity Effects in a Chain of Muon RCSs

HOM, cavity, wakefield, collider

579

F. Batsch, D. Amorim, H. Damerau, A. Grudiev, I. Karpov, E. Métral, D. Schulte
CERN, Meyrin, Switzerland
A. Chancé
CEA, Gif-sur-Yvette, France
S. Udongwo
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Funded by the European Union under Grant Agreement n.101094300
The muon collider offers an attractive path to a compact, multi-TeV lepton collider. However, the short muon lifetime leads to stringent requirements on the fast energy increase. While extreme energy gains in the order of several GeV per turn are crucial for a high elevated muon survival rate, ultra-short and intense bunches are needed to achieve large luminosity. The longitudinal beam dynamics of a chain of rapid cycling synchrotrons (RCS) for acceleration from around 60 GeV to several TeV is being investigated in the framework of the International Muon Collider Collaboration. Each RCS must have a distributed radio-frequency (RF) system with several hundred RF stations to establish stable synchrotron motion. In this contribution, the beam-induced voltage in each RCS is studied, assuming a single high-intensity bunch per beam in each direction and ILC-like 1.3 GHz accelerating structures. The impact of single- and multi-turn wakefields on longitudinal stability and RF power requirements is analysed with particle tracking simulations. Special attention is moreover paid to the beam power deposited into the higher-order modes of the RF cavities.

Poster THBP43 [1.345 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP43

About •

Received ※ 29 September 2023 — Revised ※ 05 October 2023 — Accepted ※ 10 October 2023 — Issued ※ 10 October 2023

Cite •

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

THBP55

Commissioning of NICA Injection Complex

booster, injection, electron, operation

618

V.A. Lebedev, O.I. Brovko, A.V. Butenko, E.E. Donets, B.V. Golovenskiy, E.V. Gorbachev, S.A. Kostromin, K.A. Levterov, I.N. Meshkov, A.S. Sergeev, M.M. Shandov, A.O. Sidorin, V.L. Smirnov, E. Syresin, A. Tuzikov
JINR, Dubna, Moscow Region, Russia
I. Nikolaichuk, A.Yu. Ramsdorf
JINR/VBLHEP, Dubna, Moscow region, Russia

The Nuclotron-based Ion Collider fAcility (NICA) is under construction at JINR. The NICA project goal is to provide colliding beams for studies of collisions of heavy fully stripped ions and light p¿lairized ions. The NICA Collider includes two rings with 503 m circumference each and the injection complex. For the heavy ion mode, the injection complex consists of following accelerators: 3.2 MeV/u linac (HILAC), 600 MeV/u (A/Z=6) superconducting booster synchrotron (Booster) and main superconducting synchrotron (Nuclotron) with kinetic energy up to 3.9 GeV/u (A/Z=2.5). The injection complex has been under commissioning for more than 2 years. Its Run IV was carried from October 2022 to February of 2023. It was aimed on the injection complex preparation for the collider operations in the heavy ion mode. Additionally, the slowly extracted 3.9 GeV/u xenon beam was delivered to the BM&N experiment resulting in 250 million events in the detector. The paper discusses main results of the injection complex commissioning and plans for its further development. The beam commissioning of the collider is expected in the 2nd half of 2025.

DOI •

reference for this paper ※ doi:10.18429/JACoW-HB2023-THBP55

About •

Received ※ 26 September 2023 — Revised ※ 06 October 2023 — Accepted ※ 11 October 2023 — Issued ※ 17 October 2023

Cite •

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