CYCLOTRONS2022 - List of Authors (Cai, H.R.)

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)

MOPO001	A Real-Time Controller for Rapid Energy Degrading of the CYCIAE-230 Cyclotron Beam Production System	47
	Q.Q. Song, H.R. Cai, Q.K. Guo, A.L. He, T.Y. Jiang, Y. Wang, Z.G. Yin, T.J. Zhang, B.H. Zhao CIAE, Beijing, People’s Republic of China
	The energy selection system (ESS) plays an important role in a proton therapy system. Usually, it consists of an energy degrader, a set of achromatic bending magnets, an envelope collimator, and a momentum-selecting slit. In CIAE, a dedicated beam transportation line, including these essential elements, for the CYCIAE-230 superconducting cyclotron has been designed and manufactured for study purposes. To reduce the layer switching time, e.g. typically within 50 milliseconds, this ESS system takes advantage of VME-based real-time controller design. On one side, this controller uses S-curve to direct drive the step motors of various actuators, this is done by an off-the-shelf embedded controller. On the other hand, it uses Data Distribution Service (DDS) communication protocol to tap into the nozzle control system network directly. In such a manner, the energy requirement can be efficiently handled and the controller is also responsible for the current regulation of the 46 magnets. The design of this high-efficiency controller will be reported in this paper, both from hardware and software aspects. Preliminary test results will also be evaluated and analyzed to direct further improvement of the system.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO001
About •	Received ※ 20 October 2022 — Revised ※ 27 January 2023 — Accepted ※ 30 January 2023 — Issue date ※ 10 July 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)

MOPO005	Impedance Characteristic Analysis and Matching Network Design for a 100 mA H⁻ Ion Source	58
	A.X. Ding, H.R. Cai, X.L. Jia, P.Z. Li, Z.J. Nong, G.F. Pan, J.F. Wang, H. Zhang, T.J. Zhang, X. Zheng CIAE, Beijing, People’s Republic of China
	China Institute of Atomic Energy (CIAE) has developed a series of multi-cusp H⁻ ion sources (IS) with DC beam intensity ranging from 3 to 18 mA for high intensity proton cyclotron uses such as cyclotron PET application, neutron source and boron neutron capture therapy (BNCT) facilities. Based on the previous experiences, a new project of radio frequency (RF) antenna driving ion source has been launched for pulse accelerator research. This new ion source is expected to provide over 100 mA peak intensity H⁻ beams of 60 keV and a longer maintenance interval than conventional filament-driving ion sources above. Impedance matching is indispensable for efficient RF power coupling in the whole working process of the ion source for high-intensity H⁻ beam extraction. In this paper, impedance characteristic of the IS antenna with various plasma loading is analyzed. Eight typical matching topologies are discussed on their electrical requirements. A type-L and a type-γ network are finally selected for the 2 MHz and 13.56 MHz chains respectively. This design may provide a better compromise between the matching performance and the cost of implementation for a wide dynamic loading range. Design of the network is evaluated on the power delivering efficiency in each of the two RF chains and isolation between one and the other. The IS structure and near-future work plan are also presented.
	Poster MOPO005 [1.228 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO005
About •	Received ※ 24 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 25 April 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)

MOPO019	Optimization of Rapid Magnetic Field Control of the CYCIAE-230 Cyclotron Beamline Magnets	106
	A.L. He, H.R. Cai, Q.K. Guo, P. Huang, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang, B.H. Zhao CIAE, Beijing, People’s Republic of China
	The magnetic field precise and rapid control of the beamline magnets is essential to the Energy Selection System (ESS) for the proton therapy facility. During the scanning of proton beam for therapy, the field of each beamline magnet should be precisely controlled within the set time, layer upon layer. The position of beam spot to the nozzle should undoubtedly be stable and unchanged during the process. In practice, however, due to the wide energy range of proton therapy (70 MeV-230 MeV), the dynamic response of the beamline magnets usually shows nonlinear performances at a different energy, e.g., the magnetic field may cause a significant overshoot for some specific beam energy if one ignores the nonlinear effect. More challenge is that the magnetic field drops too slowly between the energy steps, which compromises the overall performance of rapid intensity modulated scanning therapy. A dynamic PID parameter optimization method is reported in this paper to address this issue. According to the transfer function of each magnet, the entire energy range is divided into several steps. Then, the experiments are carried out to find the most suitable PID parameters for each energy step. Finally, the "beam energy - excitation current-PID parameters" lookup table (LUT) is generated and stored in the beamline control system BCS for automation. During the treatment, using the LUT allows the energy setting for beamline magnets to be adjusted automatically with the most appropriate PID parameter, guaranteeing the overall performance of rapid scanning therapy. The experimental results show the overall response time of all the beamline magnets reduced from several hundred milliseconds to less than 65 ms, which meets the design requirement of less than 80ms.
	Poster MOPO019 [0.364 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO019
About •	Received ※ 06 January 2023 — Revised ※ 30 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 10 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPO010	High Intensity Cyclotron System Integration and Commissioning for Industrialization Application	225
	P.Z. Li, H.R. Cai, S.G. Hou, X.L. Jia, G.F. Pan, G.F. Song, J.F. Wang, G. Yang, H. Zhang, T.J. Zhang CIAE, Beijing, People’s Republic of China
	Up to 430 µA beam intensity was obtained in 10 MeV CRM cyclotron (CYCIAE-CRM) at China Institute of Atomic Energy (CIAE) in 2010. Whereafter, CIAE built a series of 14 MeV high intensity external ion source cyclotrons for medical isotope application and its relevant research. Compared with research cyclotron facility, cyclotron for industrialization application requires higher level of safety, usability and stability. Therefore, mechanical and electrical system integration and optimum are applied in the cyclotron design and commissioning. Electrical devices of cyclotron, including power supply, RF amplifier and PLC controller, are integrated into four standard industrial shielding cabinets with electromagnetic compatibility (EMC) design to improve electromagnetic interference and operation stability. Besides, earthing system is rearranged in regular laboratory maintenance period to minimize electromagnetic coupling of different signal systems. Based on the previous compact system integration, communication system is integrated into each electrical device as well and could be operated in local and remote mode for the convenience of commissioning. Industrial Ethernet standard PROFINET is adopted as communication protocol to improve the efficiency of protocol interaction towards millisecond level. Regarding RF system, start-up sequence of LLRF is optimized to increase uptime and reliability. The commissioning is also presented in this paper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO010
About •	Received ※ 06 December 2022 — Revised ※ 31 December 2022 — Accepted ※ 09 February 2023 — Issue date ※ 30 October 2023
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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
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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)

MOPO001

A Real-Time Controller for Rapid Energy Degrading of the CYCIAE-230 Cyclotron Beam Production System

47

Q.Q. Song, H.R. Cai, Q.K. Guo, A.L. He, T.Y. Jiang, Y. Wang, Z.G. Yin, T.J. Zhang, B.H. Zhao
CIAE, Beijing, People’s Republic of China

The energy selection system (ESS) plays an important role in a proton therapy system. Usually, it consists of an energy degrader, a set of achromatic bending magnets, an envelope collimator, and a momentum-selecting slit. In CIAE, a dedicated beam transportation line, including these essential elements, for the CYCIAE-230 superconducting cyclotron has been designed and manufactured for study purposes. To reduce the layer switching time, e.g. typically within 50 milliseconds, this ESS system takes advantage of VME-based real-time controller design. On one side, this controller uses S-curve to direct drive the step motors of various actuators, this is done by an off-the-shelf embedded controller. On the other hand, it uses Data Distribution Service (DDS) communication protocol to tap into the nozzle control system network directly. In such a manner, the energy requirement can be efficiently handled and the controller is also responsible for the current regulation of the 46 magnets. The design of this high-efficiency controller will be reported in this paper, both from hardware and software aspects. Preliminary test results will also be evaluated and analyzed to direct further improvement of the system.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO001

About •

Received ※ 20 October 2022 — Revised ※ 27 January 2023 — Accepted ※ 30 January 2023 — Issue date ※ 10 July 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)

MOPO005

Impedance Characteristic Analysis and Matching Network Design for a 100 mA H⁻ Ion Source

58

A.X. Ding, H.R. Cai, X.L. Jia, P.Z. Li, Z.J. Nong, G.F. Pan, J.F. Wang, H. Zhang, T.J. Zhang, X. Zheng
CIAE, Beijing, People’s Republic of China

China Institute of Atomic Energy (CIAE) has developed a series of multi-cusp H⁻ ion sources (IS) with DC beam intensity ranging from 3 to 18 mA for high intensity proton cyclotron uses such as cyclotron PET application, neutron source and boron neutron capture therapy (BNCT) facilities. Based on the previous experiences, a new project of radio frequency (RF) antenna driving ion source has been launched for pulse accelerator research. This new ion source is expected to provide over 100 mA peak intensity H⁻ beams of 60 keV and a longer maintenance interval than conventional filament-driving ion sources above. Impedance matching is indispensable for efficient RF power coupling in the whole working process of the ion source for high-intensity H⁻ beam extraction. In this paper, impedance characteristic of the IS antenna with various plasma loading is analyzed. Eight typical matching topologies are discussed on their electrical requirements. A type-L and a type-γ network are finally selected for the 2 MHz and 13.56 MHz chains respectively. This design may provide a better compromise between the matching performance and the cost of implementation for a wide dynamic loading range. Design of the network is evaluated on the power delivering efficiency in each of the two RF chains and isolation between one and the other. The IS structure and near-future work plan are also presented.

Poster MOPO005 [1.228 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO005

About •

Received ※ 24 December 2022 — Revised ※ 11 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 25 April 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

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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

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

MOPO019

Optimization of Rapid Magnetic Field Control of the CYCIAE-230 Cyclotron Beamline Magnets

106

A.L. He, H.R. Cai, Q.K. Guo, P. Huang, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang, B.H. Zhao
CIAE, Beijing, People’s Republic of China

The magnetic field precise and rapid control of the beamline magnets is essential to the Energy Selection System (ESS) for the proton therapy facility. During the scanning of proton beam for therapy, the field of each beamline magnet should be precisely controlled within the set time, layer upon layer. The position of beam spot to the nozzle should undoubtedly be stable and unchanged during the process. In practice, however, due to the wide energy range of proton therapy (70 MeV-230 MeV), the dynamic response of the beamline magnets usually shows nonlinear performances at a different energy, e.g., the magnetic field may cause a significant overshoot for some specific beam energy if one ignores the nonlinear effect. More challenge is that the magnetic field drops too slowly between the energy steps, which compromises the overall performance of rapid intensity modulated scanning therapy. A dynamic PID parameter optimization method is reported in this paper to address this issue. According to the transfer function of each magnet, the entire energy range is divided into several steps. Then, the experiments are carried out to find the most suitable PID parameters for each energy step. Finally, the "beam energy - excitation current-PID parameters" lookup table (LUT) is generated and stored in the beamline control system BCS for automation. During the treatment, using the LUT allows the energy setting for beamline magnets to be adjusted automatically with the most appropriate PID parameter, guaranteeing the overall performance of rapid scanning therapy. The experimental results show the overall response time of all the beamline magnets reduced from several hundred milliseconds to less than 65 ms, which meets the design requirement of less than 80ms.

Poster MOPO019 [0.364 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO019

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Received ※ 06 January 2023 — Revised ※ 30 January 2023 — Accepted ※ 01 February 2023 — Issue date ※ 10 February 2023

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WEPO010

High Intensity Cyclotron System Integration and Commissioning for Industrialization Application

225

P.Z. Li, H.R. Cai, S.G. Hou, X.L. Jia, G.F. Pan, G.F. Song, J.F. Wang, G. Yang, H. Zhang, T.J. Zhang
CIAE, Beijing, People’s Republic of China

Up to 430 µA beam intensity was obtained in 10 MeV CRM cyclotron (CYCIAE-CRM) at China Institute of Atomic Energy (CIAE) in 2010. Whereafter, CIAE built a series of 14 MeV high intensity external ion source cyclotrons for medical isotope application and its relevant research. Compared with research cyclotron facility, cyclotron for industrialization application requires higher level of safety, usability and stability. Therefore, mechanical and electrical system integration and optimum are applied in the cyclotron design and commissioning. Electrical devices of cyclotron, including power supply, RF amplifier and PLC controller, are integrated into four standard industrial shielding cabinets with electromagnetic compatibility (EMC) design to improve electromagnetic interference and operation stability. Besides, earthing system is rearranged in regular laboratory maintenance period to minimize electromagnetic coupling of different signal systems. Based on the previous compact system integration, communication system is integrated into each electrical device as well and could be operated in local and remote mode for the convenience of commissioning. Industrial Ethernet standard PROFINET is adopted as communication protocol to improve the efficiency of protocol interaction towards millisecond level. Regarding RF system, start-up sequence of LLRF is optimized to increase uptime and reliability. The commissioning is also presented in this paper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO010

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Received ※ 06 December 2022 — Revised ※ 31 December 2022 — Accepted ※ 09 February 2023 — Issue date ※ 30 October 2023

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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

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