CYCLOTRONS2022 - List of Authors (Mu, X.)

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)

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)

WEPO017	A New Design of CYCIAE230 Superconducting Cyclotron RF-Driven System	237
	Z.G. Yin, X.L. Fu, B. Ji, X. Mu, S. Pei, J.Y. Wei, T.J. Zhang CIAE, Beijing, People’s Republic of China
	A superconducting cyclotron with a beam energy of 246.2MeV has been developed and commissioned by the China Institute of Atomic Energy. The RF system of the first CYCIAE-230 cyclotron adopts two tetrode amplifiers to drive the cavities simultaneously. The driven power is 180 degrees out of phase and each of the amplifiers was designed able to deliver 75kW RF power to the cavities. In practice, it was found that the driven power is beyond necessary and only 80kW RF power is required for the beam. Hence, an upgrade of the existing RF-driven system to the stare-of-art of solid-state technology is put forward by the CIAE cyclotron team. Furthermore, this alternative design also includes an optimization of the coupling between amplifiers and the cavities, since the old coupler shows nonidealities under long-term high-power operations. A driven schema utilizing multiple low-power capacitive couplers is designed to address this issue, taking advantage of the cavity as a power combiner. In this paper, a review of the existing RF-driven system will be given first. It will be followed by an analysis of the limitation of such a system in practice. A new design of the solid amplifier, the new driven method, and a capacitive window will also be reported.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO017
About •	Received ※ 25 December 2022 — Revised ※ 29 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 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)

THPO007	Direct Sampling Digital Low-Level RF Control for CIAE BNCT Cyclotron	311
	X. Mu, J.Y. Wei, Z.G. Yin CIAE, Beijing, People’s Republic of China X.L. Fu TRIUMF, Vancouver, Canada
	Boron Neutron Capture Therapy "BNCT" can be delivered using a high current cyclotron, resulting more compact and environmentally friendly design, yet the difficulties remain in the cyclotron part, particularly in RF systems. The high beam loading challenges the stability of the amplifiers, as well as the control loops. Especially in our case, the wall loss of each cavity is more than the beam-loading power of the CIAE BNCT cyclotron. To address the heavy beam loading coefficient, a higher-performance ADRC control algorithm is evaluated, together with the regular PID control. In the meantime, a direct sampling/synthesizing digital low-level RF control hardware design is put forward to have more flexibility in control implementation. Since this new design adopts Xilinx SOC as the main controller, it is convenient to combine real-time control algorithm with high-level control through Advanced Extensible Interface. In this LLRF design, the amplitude and phase control using PID control is implemented in the PS end, and the tuning control is taking advantage of the ADRC algorithm in the PL end. Using a symmetrical design, together with the buncher control, in total, regulation of three loops are achieved using two control boards. The software/hardware design as well as the commission result will be reported in this paper.
	Poster THPO007 [2.567 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO007
About •	Received ※ 29 December 2022 — Revised ※ 21 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 01 April 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)

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)

WEPO017

A New Design of CYCIAE230 Superconducting Cyclotron RF-Driven System

237

Z.G. Yin, X.L. Fu, B. Ji, X. Mu, S. Pei, J.Y. Wei, T.J. Zhang
CIAE, Beijing, People’s Republic of China

A superconducting cyclotron with a beam energy of 246.2MeV has been developed and commissioned by the China Institute of Atomic Energy. The RF system of the first CYCIAE-230 cyclotron adopts two tetrode amplifiers to drive the cavities simultaneously. The driven power is 180 degrees out of phase and each of the amplifiers was designed able to deliver 75kW RF power to the cavities. In practice, it was found that the driven power is beyond necessary and only 80kW RF power is required for the beam. Hence, an upgrade of the existing RF-driven system to the stare-of-art of solid-state technology is put forward by the CIAE cyclotron team. Furthermore, this alternative design also includes an optimization of the coupling between amplifiers and the cavities, since the old coupler shows nonidealities under long-term high-power operations. A driven schema utilizing multiple low-power capacitive couplers is designed to address this issue, taking advantage of the cavity as a power combiner. In this paper, a review of the existing RF-driven system will be given first. It will be followed by an analysis of the limitation of such a system in practice. A new design of the solid amplifier, the new driven method, and a capacitive window will also be reported.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO017

About •

Received ※ 25 December 2022 — Revised ※ 29 January 2023 — Accepted ※ 09 February 2023 — Issue date ※ 02 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)

THPO007

Direct Sampling Digital Low-Level RF Control for CIAE BNCT Cyclotron

311

X. Mu, J.Y. Wei, Z.G. Yin
CIAE, Beijing, People’s Republic of China
X.L. Fu
TRIUMF, Vancouver, Canada

Boron Neutron Capture Therapy "BNCT" can be delivered using a high current cyclotron, resulting more compact and environmentally friendly design, yet the difficulties remain in the cyclotron part, particularly in RF systems. The high beam loading challenges the stability of the amplifiers, as well as the control loops. Especially in our case, the wall loss of each cavity is more than the beam-loading power of the CIAE BNCT cyclotron. To address the heavy beam loading coefficient, a higher-performance ADRC control algorithm is evaluated, together with the regular PID control. In the meantime, a direct sampling/synthesizing digital low-level RF control hardware design is put forward to have more flexibility in control implementation. Since this new design adopts Xilinx SOC as the main controller, it is convenient to combine real-time control algorithm with high-level control through Advanced Extensible Interface. In this LLRF design, the amplitude and phase control using PID control is implemented in the PS end, and the tuning control is taking advantage of the ADRC algorithm in the PL end. Using a symmetrical design, together with the buncher control, in total, regulation of three loops are achieved using two control boards. The software/hardware design as well as the commission result will be reported in this paper.

Poster THPO007 [2.567 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THPO007

About •

Received ※ 29 December 2022 — Revised ※ 21 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 01 April 2023

Cite •

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