CYCLOTRONS2022 - List of Authors (Wang, Y.)

Paper	Title	Page
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)

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)

MOPO012	An Embedded Beam Diagnostic Electronics for 230 MeV Superconducting Cyclotron Radial Probe and Scanning Wires	80
	T.Y. Jiang, P. Liu, X. Mu, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang CIAE, Beijing, People’s Republic of China
	For the 230MeV superconducting cyclotron, once again, the differential radial probe has been proven to be crucial for the beam commission procedure. It can provide various information about the particles inside the cyclotron, such as the vertical position, the relative intensity as well as the oscillation frequency and radius, etc. In practice, however, the electronics system suffered from the leaking alternating RF field as well as the static magnetic field. Besides the EM shielding, an absorptive high-frequency filter has been included as the first element of the readout electronics. A high dynamic range readout electronic unit has been included to adapt to the fluctuation of the beam in the hole commissioning phase. The electronics box is designed as a network-attached embedded device so that it can be powered by a POE switch and transmits measurement results via MODBUS protocol. A dedicated digital signal processor and calibration units are also included, together with the ADCs, to facilitate the daily calibration process. The same electronics are used for the beamline wire scan system to determine the position of the beam, with a small improvement at a lower range. The design of this multi-purpose beam diagnostics electronics will be reviewed in this paper, together with several measurement results. zhiguoyin@ciae.ac.cn
	Poster MOPO012 [0.721 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO012
About •	Received ※ 01 January 2023 — Revised ※ 27 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 27 April 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO016	Control of Cyclotron Vertical Deflector for Proton Therapy	95
	F.D. Yang, T.Y. Jiang, X. Mu, Y. Wang, Z.G. Yin, T.J. Zhang CIAE, Beijing, People’s Republic of China X.L. Fu TRIUMF, Vancouver, Canada
	China Institute of Atomic Energy (CIAE) has designed a superconducting cyclotron CYCIAE-230 to enhance the domestic development of proton therapy. A research program on the beamline and experimental stations for the proton therapy and the space science was launched by China National Nuclear Corporation (CNNC). The modern therapy methodology often requires rapid beam modulation on both the beam energy and the intensity. In this scenario, a vertical deflector is designed and installed in the cyclotron’s central region. Applying a high-voltage electric field between the two plates can quickly adjust the intensity of the low-energy beam. Nevertheless, the voltage applied is nonlinear to the beam intensity. According to this requirement, a homemade controller for the vertical deflector is designed. Since the beam loss caused by the energy degrader is also nonlinear, this controller can compensate for the beam loss caused by energy modulation. To realize real-time control, the controller combines Field Programmable Gate Array (FPGA) and Digital Signal Process (DSP) as its control scheme design. Carried out by the DSP by interpolating the lookup table data, a feed-forward regulation is also designed to take care of the nonlinear compensation for the beam loss on the energy degrader. In the meantime, an ionized chamber provides feedback readings of the intensity just before the nozzle. A PID algorithm is also included by using FPGA, to archive the feedback control of the vertical deflector.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO016
About •	Received ※ 30 December 2022 — Revised ※ 27 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 May 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)

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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THPO006	Design and Implementation of Robot Adapter in Therapy Control System	307
	S.M. Jiang, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang CIAE, Beijing, People’s Republic of China Q. Ran Konica Minolta Zaiqi Medical Products (Shanghai) Co., LTD., Shanghai, People’s Republic of China
	The China Institute of Atomic Energy (CIAE) in Beijing has designed and established a proton therapy facility based on a superconducting cyclotron CYCIAE-230, which can provide proton beams with energy from 70 MeV to 230 MeV for cancer treatment. As the most critical and core part of the proton therapy system, therapy control system (TCS) consists of various components, each of which has corresponding processing services. Motion control of external hardware systems is one of the essential parts of TCS development, and adapters figure prominently in the interaction between services and these external hardware systems. One of the adapters, called robot adapter, is specially developed for the external robotic couch system, which is a vital equipment that directly contacts patients in the whole process of proton therapy. This adapter serves as the connection between TCS and robotic couch for communication and corresponding movement. In this paper, we introduced the communication protocols, design, and characteristics of robot adapter as well as the actual test contents and results with the robotic couch. The test results indicated that the robot adapter can satisfy the needs of couch motion control and status monitoring.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO006
About •	Received ※ 04 January 2023 — Revised ※ 12 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 22 March 2023
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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
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Paper

Title

Page

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)

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)

MOPO012

An Embedded Beam Diagnostic Electronics for 230 MeV Superconducting Cyclotron Radial Probe and Scanning Wires

80

T.Y. Jiang, P. Liu, X. Mu, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang
CIAE, Beijing, People’s Republic of China

For the 230MeV superconducting cyclotron, once again, the differential radial probe has been proven to be crucial for the beam commission procedure. It can provide various information about the particles inside the cyclotron, such as the vertical position, the relative intensity as well as the oscillation frequency and radius, etc. In practice, however, the electronics system suffered from the leaking alternating RF field as well as the static magnetic field. Besides the EM shielding, an absorptive high-frequency filter has been included as the first element of the readout electronics. A high dynamic range readout electronic unit has been included to adapt to the fluctuation of the beam in the hole commissioning phase. The electronics box is designed as a network-attached embedded device so that it can be powered by a POE switch and transmits measurement results via MODBUS protocol. A dedicated digital signal processor and calibration units are also included, together with the ADCs, to facilitate the daily calibration process. The same electronics are used for the beamline wire scan system to determine the position of the beam, with a small improvement at a lower range. The design of this multi-purpose beam diagnostics electronics will be reviewed in this paper, together with several measurement results.
zhiguoyin@ciae.ac.cn

Poster MOPO012 [0.721 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO012

About •

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

Cite •

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

MOPO016

Control of Cyclotron Vertical Deflector for Proton Therapy

95

F.D. Yang, T.Y. Jiang, X. Mu, Y. Wang, Z.G. Yin, T.J. Zhang
CIAE, Beijing, People’s Republic of China
X.L. Fu
TRIUMF, Vancouver, Canada

China Institute of Atomic Energy (CIAE) has designed a superconducting cyclotron CYCIAE-230 to enhance the domestic development of proton therapy. A research program on the beamline and experimental stations for the proton therapy and the space science was launched by China National Nuclear Corporation (CNNC). The modern therapy methodology often requires rapid beam modulation on both the beam energy and the intensity. In this scenario, a vertical deflector is designed and installed in the cyclotron’s central region. Applying a high-voltage electric field between the two plates can quickly adjust the intensity of the low-energy beam. Nevertheless, the voltage applied is nonlinear to the beam intensity. According to this requirement, a homemade controller for the vertical deflector is designed. Since the beam loss caused by the energy degrader is also nonlinear, this controller can compensate for the beam loss caused by energy modulation. To realize real-time control, the controller combines Field Programmable Gate Array (FPGA) and Digital Signal Process (DSP) as its control scheme design. Carried out by the DSP by interpolating the lookup table data, a feed-forward regulation is also designed to take care of the nonlinear compensation for the beam loss on the energy degrader. In the meantime, an ionized chamber provides feedback readings of the intensity just before the nozzle. A PID algorithm is also included by using FPGA, to archive the feedback control of the vertical deflector.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO016

About •

Received ※ 30 December 2022 — Revised ※ 27 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 May 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)

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

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

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THPO006

Design and Implementation of Robot Adapter in Therapy Control System

307

S.M. Jiang, Q.Q. Song, Y. Wang, Z.G. Yin, T.J. Zhang
CIAE, Beijing, People’s Republic of China
Q. Ran
Konica Minolta Zaiqi Medical Products (Shanghai) Co., LTD., Shanghai, People’s Republic of China

The China Institute of Atomic Energy (CIAE) in Beijing has designed and established a proton therapy facility based on a superconducting cyclotron CYCIAE-230, which can provide proton beams with energy from 70 MeV to 230 MeV for cancer treatment. As the most critical and core part of the proton therapy system, therapy control system (TCS) consists of various components, each of which has corresponding processing services. Motion control of external hardware systems is one of the essential parts of TCS development, and adapters figure prominently in the interaction between services and these external hardware systems. One of the adapters, called robot adapter, is specially developed for the external robotic couch system, which is a vital equipment that directly contacts patients in the whole process of proton therapy. This adapter serves as the connection between TCS and robotic couch for communication and corresponding movement. In this paper, we introduced the communication protocols, design, and characteristics of robot adapter as well as the actual test contents and results with the robotic couch. The test results indicated that the robot adapter can satisfy the needs of couch motion control and status monitoring.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO006

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Received ※ 04 January 2023 — Revised ※ 12 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 22 March 2023

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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

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

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