CYCLOTRONS2022 - List of Authors (Zhu, X.F.)

Paper	Title	Page
MOAO02	The Commissioning of a 230 MeV Superconducting Cyclotron CYCIAE-230	15
	C. Wang, H.R. Cai, W.F. Fu, A.L. He, M.Z. Hu, B. Ji, L.Y. Ji, X.L. Jia, Y. Jia, T.Y. Jiang, J. Liu, J.Y. Liu, P. Liu, Z.W. Liu, X. Mu, S. Pei, G.F. Song, Q.Q. Song, F. Wang, J.Y. Wei, L.P. Wen, J.S. Xing, Z.G. Yin, D.Z. Zhang, S.P. Zhang, T.J. Zhang, X. Zheng, H. Zhou, P.F. Zhu, X.F. Zhu CIAE, Beijing, People’s Republic of China
	There are very strong demands for proton accelera-tors in medium energy range in recent years due to the fast growth of proton therapy and the space science in China. For the applications of proton therapy and pro-ton irradiation, the energy range of proton beam is usually from 200MeV to 250MeV, or even higher for astronavigation [1]. An R&D project for constructing a 230MeV superconducting cyclotron (CYCIAE-230) has been initiated at China Institute of Atomic Energy (CIAE) since Jan 2015. In July of 2016, after the fund-ing was approved by China National Nuclear Corpora-tion (CNNC), the construction project was fully launched. In Dec 2019, the superconducting main magnet and the RF system were transferred to the new-ly built commissioning site. Then, the RF commission-ing, ion source and central region test were performed even during the pandemic in early 2020. In September 2020, after finishing the commissioning tests of all subsystems, the beam was reached the extraction channel but with very low efficiency. Since then, with more efforts on beam diagnostics, the fine tuning of the beam phase and the adjusting of the superconduct-ing coil have been proven to be useful to get higher beam extraction efficiency ~55%. In this paper, the commissioning of the key components, including the main magnet, SC coils, internal ion source and central region, extraction system, etc, as well as the commis-sioning progress of the machine CYCIAE-230 will be presented.
	Slides MOAO02 [10.305 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOAO02
About •	Received ※ 24 January 2023 — Revised ※ 25 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 10 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO004	Beam Dump Development for High Power Proton and Electron Beam	54
	J.Y. Liu, H.R. Cai, M.Z. Hu, G.F. Pan, S. Pei, G.F. Song, L. Wang, Y. Wang, S.M. Wei, Z.G. Yin, S.P. Zhang, T.J. Zhang, X.F. Zhu CIAE, Beijing, People’s Republic of China
	The high-intensity 100 MeV proton cyclotron CYCIAE-100 had provided 52 kW beam to the beam dump in 2018, is planning to upgrade at China Institute of Atomic Energy(CIAE). It is designed to provide a 75~100 MeV, 1 mA proton beam. So, a new beam dump for higher beam power have been developed since 2020. At the same time, a 1:4 scale, RF cavity with Q value up to 42000, is constructed for the engineering feasibility verification of a 2 GeV/6 MW CW FFAG, which is also being considered as a main accelerating cavity of a 100 kW electron accelerator. The electron beam will be rotated and accelerated 7 times by the gradient dipoles and the high Q cavity. The beam dump is designed to also use for the 100kW electron beam. With the same-level beam power of the two accelerators above the content, a beam dump for absorbing two kinds of particle beams according to the characteristics of the modification was designed. The energy deposition of 100MeV proton beam and 5MeV electron beam in the beam dump was investigated by the Monte-Carlo simulation program FLUKA. The beam dump cooling structure was optimizing by ICEM-CFD and fluent, so that the beam dump temperature was controlled less than 100°C, and the maximum temperature on the beam dump is less than 450°C. The beam dump is designed as a cube (450200200, unit:mm) with two 2.5°V-type copper pentagon and two flat parts. All the details about the simulation of energy deposition, thermal distribution and structure design will be presented in the paper.
	Poster MOPO004 [3.428 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO004
About •	Received ※ 31 December 2022 — Revised ※ 26 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 25 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO007	The Design and Commission of Vacuum System for CYCIAE-230 Superconducting Cyclotron	66
	S.P. Zhang, H.R. Cai, W.F. Fu, B. Ji, J.Y. Liu, G.F. Pan, C. Wang, Z.G. Yin, T.J. Zhang, H. Zhou, X.F. Zhu CIAE, Beijing, People’s Republic of China
	In this paper, the design and installation CYCIAE-230 superconducting cyclotron main vacuum system’s equipment and the cryogenic systems based on the liquid helium zero-boiling-off technology for the CYCIAE-230 superconducting cyclotrons are described. The vacuum in the particle acceleration cavity is 2x10^-4 Pa. The main technical features of the accelerator vacuum system are that the main magnet cover plate with diameter 3.12m are used as a part of the main vacuum chamber, 8 magnetic poles, 8 high frequency resonators, and 2 sets of striper targets and 2 sets of radial targets are installed in the main vacuum chamber, resulting in technical difficulties such as large surface gas discharge, virtual leakage, high leakage of magnetic flux at the installation position of vacuum equipment (up to 2000 gauss) and so on. The main vacuum system is designed as 9 sets of TMP with magnet shields installed on the valley of magnet poles, which also used as RF cavity.
	Poster MOPO007 [1.509 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO007
About •	Received ※ 06 February 2023 — Revised ※ 07 February 2023 — Accepted ※ 03 August 2023 — Issue date ※ 12 October 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO008	PLC Based Vacuum Control and Interlock System of the CYCIAE-230 Superconducting Cyclotron Beam Line	70
	M.Z. Hu, H.R. Cai, A.L. He, S.M. Jiang, T.Y. Jiang, J.Y. Liu, P. Liu, Q.Q. Song, Y. Wang, F.D. Yang, Z.G. Yin, T.J. Zhang, B.H. Zhao, X.F. Zhu CIAE, Beijing, People’s Republic of China
	In the CYCIAE-230 superconducting cyclotron beam line, a vacuum system capable of providing a pressure of about 5·10^-4 Pa is required for particle beam transport. In order to provide adequate interlocking to safeguard the vacuum environment and ensure the regular transmission of particles within the beam line, a vacuum control system based on programmable logic controller (PLC) has been developed and integrated into the accelerator monitoring system. The PLC not only interfaces with the quick-acting relay based on interlocking signals but also interfaces with the equipment based on Profibus communication to monitor and control various parameters in the vacuum system, such as pump speed, vacuum pressure reading, valve status, water cooling status, etc. This work presents the structure and interface logic necessary for communication with a series of valves, vacuum gauges, and molecular pump controllers. Also presented is an interface approach between vacuum control and the rest of the accelerator control system.
	Poster MOPO008 [3.051 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO008
About •	Received ※ 27 December 2022 — Revised ※ 26 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 01 April 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPO001	Field Matching of F-D-F, Gap Shaping Magnets for a 2 GeV CW FFA	200
	W.F. Fu, T.J. Bian, C. Wang, S.P. Zhang, T.J. Zhang, H. Zhou, X.F. Zhu CIAE, Beijing, People’s Republic of China
	Funding: Work supported by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901. Fixed Field Alternating Gradient Accelerators have been developed for decades. A continuous wave (CW) 2 GeV FFA which aims at high-power proton beam applications is under developing in China Institute of Atomic Energy (CIAE). To avoid dangerous resonance lines and manipulate the tune diagram flexibly, 3rd order magnetic field is applied along the radius and 10-fold symmetrical F-D-F scheme has been proved to be feasible. In this paper, Integral Equation Method (IEM) is introduced and shown more efficient than adjusting the variable gap manually, saving time for magnet design. First of all, the radial mean field is set as a main design goal and the Δ H at different radii is solved by linear equations based on IEM. The isochronism is done when the mean field is well matched with the design value, whereas some precise corrections are needed for the oscillating frequency Vr and Vz, such as fringe field effects and multipole components near the end of pole face. The tune shift caused by fringe field is also included in this paper. Fringe field is more crucial for HTS magnets especially, since the leaked field of superconducting coil is ~1 kGs. Considering that, we apply an angular matching method to compensate the tune shift by fringe field.
	Poster WEPO001 [3.442 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO001
About •	Received ※ 30 December 2022 — Revised ※ 28 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 12 June 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THAI01	Recent Progress of Research and Development for the Cost-Effective, Energy-Efficient Proton Accelerator CYCIAE-2000	245
	T.J. Zhang, H.R. Cai, Z.C. Chu, W.F. Fu, A.L. He, M.Z. Hu, X.L. Jia, Z.J. Jin, H. Le, J. Lin, J.Y. Liu, X. Mu, G.F. Pan, S. Pei, Q.Q. Song, C. Wang, F. Wang, Y. Wang, Z.G. Yin, Z.Y. Yin, S.P. Zhang, B.H. Zhao, H. Zhou, X.F. Zhu CIAE, Beijing, People’s Republic of China
	Funding: This work was supported in part by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901. The MW class proton accelerators are expected to play important role in many fields, attracting institutions to continue research and tackle key problems. The CW isochronous accelerator obtains a high power beam with higher energy efficiency, which is very attractive to many applications. Scholars generally believe that the energy limitation of the isochronous cyclotron is ~1 GeV. To get higher beam power by the isochronous machine, enhancing the beam focusing become the most important issue. Adjusting the radial gradient of the average magnetic field makes the field distribution match the isochronism. When we adjust the radial gradient of the peak field, the first-order gradient is equivalent to the quadrupole field, the second-order, the hexapole field, and so on. Just like the synchrotron, there are quadrupoles, hexapole magnets, and so on, along the orbits to get higher energy, as all we know. If we adjust the radial gradient for the peak field of an FFAG’s FDF lattice and cooperate with the angular width (azimuth flutter) and spiral angle (edge focusing) of the traditional cyclotron pole, we can manipulate the working path in the tune diagram very flexibly. During enhancing the axial focusing, both the beam intensity and the energy of the isochronous accelerator are significantly increased. And a 2 GeV CW FFAG with 3 mA of average beam intensity is designed. It is essentially an isochronous cyclotron although we use 10 folders of FDF lattices. The key difficulty is that the magnetic field and each order of gradient should be accurately adjusted in a large radius range. As a high-power proton accelerator with high energy efficiency, we adopt high-temperature superconducting technology for the magnets. 15 RF cavities with a Q value of 90000 provide energy gain per turn of ~15 MeV to ensure the CW beam intensity reaches 3 mA. A 1:4 scale, 15 ton HTS magnet, and a 1:4 scale, 177 MHz cavity have been completed. The results of such R&D will also be presented in this
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THAI01
About •	Received ※ 20 January 2023 — Revised ※ 24 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 04 April 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPO015	R&D Studies on A 177.6 MHz 1:4 Scale Boat Shape Prototype RF Cavity for the 2 GeV CW FFA	338
	S. Pei, L.L. Guan, Y. Jia, Z.J. Jin, M. Li, J.Y. Liu, G.F. Pan, F. Wang, L. Wang, Y. Wang, G. Yang, Z.G. Yin, S.P. Zhang, T.J. Zhang, X.F. Zhu CIAE, Beijing, People’s Republic of China B. Li, S.B. Xia, Y. Xing ASIPP, Hefei, People’s Republic of China
	Funding: Work supported in part by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901. A proton circular accelerator complex composed of a 100 MeV separated radial sector cyclotron, an 800 MeV separated spiral sector cyclotron and a 2 GeV FFA was proposed and is being studied at CIAE. To satisfy the beam dynamics requirements of the FFA, NC RF cavity with high Q and R will be adopted. It is found that the boat shape cavity is the most promising candidate. Therefore, R&D on a 177.6 MHz 1:4 scale boat shape prototype cavity is being carried out to study all aspects of developing such a high-power cavity. In this scenario, self-consistent multi-physics coupled simulation study with ANSYS HFSS and Workbench was carried out. This paper describes the method to deal with a mechanical model including hundreds of bodies in the FEM analysis and shows the simulation results. In addition, the manufacturing technology and some testing results are also presented.
	Poster THPO015 [3.234 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO015
About •	Received ※ 04 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 16 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

The Commissioning of a 230 MeV Superconducting Cyclotron CYCIAE-230

15

C. Wang, H.R. Cai, W.F. Fu, A.L. He, M.Z. Hu, B. Ji, L.Y. Ji, X.L. Jia, Y. Jia, T.Y. Jiang, J. Liu, J.Y. Liu, P. Liu, Z.W. Liu, X. Mu, S. Pei, G.F. Song, Q.Q. Song, F. Wang, J.Y. Wei, L.P. Wen, J.S. Xing, Z.G. Yin, D.Z. Zhang, S.P. Zhang, T.J. Zhang, X. Zheng, H. Zhou, P.F. Zhu, X.F. Zhu
CIAE, Beijing, People’s Republic of China

There are very strong demands for proton accelera-tors in medium energy range in recent years due to the fast growth of proton therapy and the space science in China. For the applications of proton therapy and pro-ton irradiation, the energy range of proton beam is usually from 200MeV to 250MeV, or even higher for astronavigation [1]. An R&D project for constructing a 230MeV superconducting cyclotron (CYCIAE-230) has been initiated at China Institute of Atomic Energy (CIAE) since Jan 2015. In July of 2016, after the fund-ing was approved by China National Nuclear Corpora-tion (CNNC), the construction project was fully launched. In Dec 2019, the superconducting main magnet and the RF system were transferred to the new-ly built commissioning site. Then, the RF commission-ing, ion source and central region test were performed even during the pandemic in early 2020. In September 2020, after finishing the commissioning tests of all subsystems, the beam was reached the extraction channel but with very low efficiency. Since then, with more efforts on beam diagnostics, the fine tuning of the beam phase and the adjusting of the superconduct-ing coil have been proven to be useful to get higher beam extraction efficiency ~55%. In this paper, the commissioning of the key components, including the main magnet, SC coils, internal ion source and central region, extraction system, etc, as well as the commis-sioning progress of the machine CYCIAE-230 will be presented.

Slides MOAO02 [10.305 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOAO02

About •

Received ※ 24 January 2023 — Revised ※ 25 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 10 June 2023

Cite •

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

MOPO004

Beam Dump Development for High Power Proton and Electron Beam

54

J.Y. Liu, H.R. Cai, M.Z. Hu, G.F. Pan, S. Pei, G.F. Song, L. Wang, Y. Wang, S.M. Wei, Z.G. Yin, S.P. Zhang, T.J. Zhang, X.F. Zhu
CIAE, Beijing, People’s Republic of China

The high-intensity 100 MeV proton cyclotron CYCIAE-100 had provided 52 kW beam to the beam dump in 2018, is planning to upgrade at China Institute of Atomic Energy(CIAE). It is designed to provide a 75~100 MeV, 1 mA proton beam. So, a new beam dump for higher beam power have been developed since 2020. At the same time, a 1:4 scale, RF cavity with Q value up to 42000, is constructed for the engineering feasibility verification of a 2 GeV/6 MW CW FFAG, which is also being considered as a main accelerating cavity of a 100 kW electron accelerator. The electron beam will be rotated and accelerated 7 times by the gradient dipoles and the high Q cavity. The beam dump is designed to also use for the 100kW electron beam. With the same-level beam power of the two accelerators above the content, a beam dump for absorbing two kinds of particle beams according to the characteristics of the modification was designed. The energy deposition of 100MeV proton beam and 5MeV electron beam in the beam dump was investigated by the Monte-Carlo simulation program FLUKA. The beam dump cooling structure was optimizing by ICEM-CFD and fluent, so that the beam dump temperature was controlled less than 100°C, and the maximum temperature on the beam dump is less than 450°C. The beam dump is designed as a cube (450*200*200, unit:mm) with two 2.5°V-type copper pentagon and two flat parts. All the details about the simulation of energy deposition, thermal distribution and structure design will be presented in the paper.

Poster MOPO004 [3.428 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO004

About •

Received ※ 31 December 2022 — Revised ※ 26 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 25 June 2023

Cite •

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

MOPO007

The Design and Commission of Vacuum System for CYCIAE-230 Superconducting Cyclotron

66

S.P. Zhang, H.R. Cai, W.F. Fu, B. Ji, J.Y. Liu, G.F. Pan, C. Wang, Z.G. Yin, T.J. Zhang, H. Zhou, X.F. Zhu
CIAE, Beijing, People’s Republic of China

In this paper, the design and installation CYCIAE-230 superconducting cyclotron main vacuum system’s equipment and the cryogenic systems based on the liquid helium zero-boiling-off technology for the CYCIAE-230 superconducting cyclotrons are described. The vacuum in the particle acceleration cavity is 2x10^-4 Pa. The main technical features of the accelerator vacuum system are that the main magnet cover plate with diameter 3.12m are used as a part of the main vacuum chamber, 8 magnetic poles, 8 high frequency resonators, and 2 sets of striper targets and 2 sets of radial targets are installed in the main vacuum chamber, resulting in technical difficulties such as large surface gas discharge, virtual leakage, high leakage of magnetic flux at the installation position of vacuum equipment (up to 2000 gauss) and so on. The main vacuum system is designed as 9 sets of TMP with magnet shields installed on the valley of magnet poles, which also used as RF cavity.

Poster MOPO007 [1.509 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO007

About •

Received ※ 06 February 2023 — Revised ※ 07 February 2023 — Accepted ※ 03 August 2023 — Issue date ※ 12 October 2023

Cite •

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

MOPO008

PLC Based Vacuum Control and Interlock System of the CYCIAE-230 Superconducting Cyclotron Beam Line

70

M.Z. Hu, H.R. Cai, A.L. He, S.M. Jiang, T.Y. Jiang, J.Y. Liu, P. Liu, Q.Q. Song, Y. Wang, F.D. Yang, Z.G. Yin, T.J. Zhang, B.H. Zhao, X.F. Zhu
CIAE, Beijing, People’s Republic of China

In the CYCIAE-230 superconducting cyclotron beam line, a vacuum system capable of providing a pressure of about 5·10^-4 Pa is required for particle beam transport. In order to provide adequate interlocking to safeguard the vacuum environment and ensure the regular transmission of particles within the beam line, a vacuum control system based on programmable logic controller (PLC) has been developed and integrated into the accelerator monitoring system. The PLC not only interfaces with the quick-acting relay based on interlocking signals but also interfaces with the equipment based on Profibus communication to monitor and control various parameters in the vacuum system, such as pump speed, vacuum pressure reading, valve status, water cooling status, etc. This work presents the structure and interface logic necessary for communication with a series of valves, vacuum gauges, and molecular pump controllers. Also presented is an interface approach between vacuum control and the rest of the accelerator control system.

Poster MOPO008 [3.051 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO008

About •

Received ※ 27 December 2022 — Revised ※ 26 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 01 April 2023

Cite •

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

WEPO001

Field Matching of F-D-F, Gap Shaping Magnets for a 2 GeV CW FFA

200

W.F. Fu, T.J. Bian, C. Wang, S.P. Zhang, T.J. Zhang, H. Zhou, X.F. Zhu
CIAE, Beijing, People’s Republic of China

Funding: Work supported by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901.
Fixed Field Alternating Gradient Accelerators have been developed for decades. A continuous wave (CW) 2 GeV FFA which aims at high-power proton beam applications is under developing in China Institute of Atomic Energy (CIAE). To avoid dangerous resonance lines and manipulate the tune diagram flexibly, 3rd order magnetic field is applied along the radius and 10-fold symmetrical F-D-F scheme has been proved to be feasible. In this paper, Integral Equation Method (IEM) is introduced and shown more efficient than adjusting the variable gap manually, saving time for magnet design. First of all, the radial mean field is set as a main design goal and the Δ H at different radii is solved by linear equations based on IEM. The isochronism is done when the mean field is well matched with the design value, whereas some precise corrections are needed for the oscillating frequency Vr and Vz, such as fringe field effects and multipole components near the end of pole face. The tune shift caused by fringe field is also included in this paper. Fringe field is more crucial for HTS magnets especially, since the leaked field of superconducting coil is ~1 kGs. Considering that, we apply an angular matching method to compensate the tune shift by fringe field.

Poster WEPO001 [3.442 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO001

About •

Received ※ 30 December 2022 — Revised ※ 28 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 12 June 2023

Cite •

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

THAI01

Recent Progress of Research and Development for the Cost-Effective, Energy-Efficient Proton Accelerator CYCIAE-2000

245

T.J. Zhang, H.R. Cai, Z.C. Chu, W.F. Fu, A.L. He, M.Z. Hu, X.L. Jia, Z.J. Jin, H. Le, J. Lin, J.Y. Liu, X. Mu, G.F. Pan, S. Pei, Q.Q. Song, C. Wang, F. Wang, Y. Wang, Z.G. Yin, Z.Y. Yin, S.P. Zhang, B.H. Zhao, H. Zhou, X.F. Zhu
CIAE, Beijing, People’s Republic of China

Funding: This work was supported in part by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901.
The MW class proton accelerators are expected to play important role in many fields, attracting institutions to continue research and tackle key problems. The CW isochronous accelerator obtains a high power beam with higher energy efficiency, which is very attractive to many applications. Scholars generally believe that the energy limitation of the isochronous cyclotron is ~1 GeV. To get higher beam power by the isochronous machine, enhancing the beam focusing become the most important issue. Adjusting the radial gradient of the average magnetic field makes the field distribution match the isochronism. When we adjust the radial gradient of the peak field, the first-order gradient is equivalent to the quadrupole field, the second-order, the hexapole field, and so on. Just like the synchrotron, there are quadrupoles, hexapole magnets, and so on, along the orbits to get higher energy, as all we know. If we adjust the radial gradient for the peak field of an FFAG’s FDF lattice and cooperate with the angular width (azimuth flutter) and spiral angle (edge focusing) of the traditional cyclotron pole, we can manipulate the working path in the tune diagram very flexibly. During enhancing the axial focusing, both the beam intensity and the energy of the isochronous accelerator are significantly increased. And a 2 GeV CW FFAG with 3 mA of average beam intensity is designed. It is essentially an isochronous cyclotron although we use 10 folders of FDF lattices. The key difficulty is that the magnetic field and each order of gradient should be accurately adjusted in a large radius range. As a high-power proton accelerator with high energy efficiency, we adopt high-temperature superconducting technology for the magnets. 15 RF cavities with a Q value of 90000 provide energy gain per turn of ~15 MeV to ensure the CW beam intensity reaches 3 mA. A 1:4 scale, 15 ton HTS magnet, and a 1:4 scale, 177 MHz cavity have been completed. The results of such R&D will also be presented in this

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THAI01

About •

Received ※ 20 January 2023 — Revised ※ 24 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 04 April 2023

Cite •

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

THPO015

R&D Studies on A 177.6 MHz 1:4 Scale Boat Shape Prototype RF Cavity for the 2 GeV CW FFA

338

S. Pei, L.L. Guan, Y. Jia, Z.J. Jin, M. Li, J.Y. Liu, G.F. Pan, F. Wang, L. Wang, Y. Wang, G. Yang, Z.G. Yin, S.P. Zhang, T.J. Zhang, X.F. Zhu
CIAE, Beijing, People’s Republic of China
B. Li, S.B. Xia, Y. Xing
ASIPP, Hefei, People’s Republic of China

Funding: Work supported in part by the National Natural Science Foundation of China under Grant 12135020 and the basic research fund from the Ministry of Finance of China under Grant BRF201901.
A proton circular accelerator complex composed of a 100 MeV separated radial sector cyclotron, an 800 MeV separated spiral sector cyclotron and a 2 GeV FFA was proposed and is being studied at CIAE. To satisfy the beam dynamics requirements of the FFA, NC RF cavity with high Q and R will be adopted. It is found that the boat shape cavity is the most promising candidate. Therefore, R&D on a 177.6 MHz 1:4 scale boat shape prototype cavity is being carried out to study all aspects of developing such a high-power cavity. In this scenario, self-consistent multi-physics coupled simulation study with ANSYS HFSS and Workbench was carried out. This paper describes the method to deal with a mechanical model including hundreds of bodies in the FEM analysis and shows the simulation results. In addition, the manufacturing technology and some testing results are also presented.

Poster THPO015 [3.234 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO015

About •

Received ※ 04 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 16 July 2023

Cite •

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