CYCLOTRONS2022 - List of Keywords (resonance)

Paper	Title	Other Keywords	Page
MOPO018	The Magnetic Field Design of a 16 MeV Variable Energy Cyclotron	cyclotron, extraction, simulation, magnet-design	103
	Z. Wu, K.Z. Ding, J. Zhou ASIPP, Hefei, People’s Republic of China S. Xu HFCIM, HeFei, People’s Republic of China
	The development of a 16 MeV H⁻ cyclotron is in progress at CIM company (Hefei, China). Such machine is designed for radio-isotope production which is used for nuclear medicine. Beam extraction is ensured by means of stripper foils located at different radii to achieve variable extraction energy between 10 and 16 MeV. In this paper, the main magnet design was demonstrated in detail. An AVF magnet with four radial sectors was adopt to get strong axial focusing. The hill angular widths and hill gaps with radius were designed to meet the isochronous magnetic field. The tunes were optimized to avoid dangerous resonance. The result of magnet design was verified by beam dynamics simulations. After the presentation of the magnet design, some results on stripping extraction were also discussed. TOSCA (OPERA-3D) was used to perform 3D magnetic field simulation. An efficient beam simulation code developed by MATLAB was used to do beam dynamics simulations.
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO018
About •	Received ※ 12 February 2023 — Revised ※ 13 February 2023 — Accepted ※ 14 February 2023 — Issue date ※ 10 May 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPO008	H^- Intra-Beam Stripping Loss Rate in Isochronous Cyclotron	cyclotron, linac, target, electron	219
	Y.-N. Rao TRIUMF, Vancouver, Canada
	Funding: This work was funded by TRIUMF which receives federal funding via a contribution agreement with the National Research Council of Canada. Binary collisions inside a H^- bunch result in H^- stripping and subsequent particle loss. This phenomenon, called intra-beam stripping, was observed in LEAR and SNS superconducting linac. We mimic the derivation made for the linac to derive the intra-beam stripping loss rate for an isochronous cyclotron. And then, we apply this theory to the TRIUMF 500 MeV H^- cyclotron to estimate the loss.
	Poster WEPO008 [1.189 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO008
About •	Received ※ 05 December 2022 — Revised ※ 04 February 2023 — Accepted ※ 07 February 2023 — Issue date ※ 14 July 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	cyclotron, cavity, coupling, electron	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	cavity, cyclotron, extraction, proton	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)

THAO01	On the Energy Limit of Compact Isochronous Cyclotrons	cyclotron, hadrontherapy, focusing, hadron	255
	W.J.G.M. Kleeven IBA, Louvain-la-Neuve, Belgium
	Existing analytical models for transverse beam dynamics in isochronous cyclotrons are often not valid or not precise for relativistic energies. The main difficulty in developing such models lies in the fact that cross-terms between derivatives of the average magnetic field and the azimuthally varying components cannot be neglected at higher energies. Taking such cross-terms rigorously into account results in an even larger number of terms that need to be included in the equations. In this paper, a method is developed which is relativistically correct and which provides results that are practical and easy to use. We derive new formulas, graphs, and tables for the radial and vertical tunes in terms of the flutter, its radial derivatives, the spiral angle and the relativistic gamma. Using this method, we study the 2nur=N structural resonance (N is number of sectors) and provide formulas and graphs for its stopband. Combining those equations with the new equation for the vertical tune, we find the stability zone and the energy limit of compact isochronous cyclotrons for any value of N. We confront the new analytical method with closed orbit simulations of the IBA C400 cyclotron for hadron therapy.
	Slides THAO01 [6.641 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THAO01
About •	Received ※ 22 December 2022 — Revised ※ 05 February 2023 — Accepted ※ 07 February 2023 — Issue date ※ 02 April 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THBI01	Status on NHa C400 Cyclotron for Hadrontherapy	cyclotron, extraction, proton, hadron	264
	J. Mandrillon, M. Abs, P. Cailliau, S. Deprez, X. Donzel, G. Goosse, Y. Jongen, W.J.G.M. Kleeven, L.C.L. Koffel, V. Nuttens, Y. Otu, Y. Paradis IBA, Louvain-la-Neuve, Belgium O. Cosson, L. Maunoury, Ph. Velten NHa, Caen, France
	C400 is an isochronous cyclotron for cancer therapy delivering high dose rates of alphas to carbons at 400 MeV/amu extracted by electrostatic deflector and protons at 260 MeV extracted by stripping of molecular hydrogen. IBA started to pre-design the system more than 13 years ago in collaboration with JINR. The responsibility for the development of C400 has meanwhile been taken over by the French company Normandy Hadontherapy (NHa). However, the study and design work continued with a very strong involvement of IBA for the past 3 years, from concept on paper to reality. We will describe the most innovative concepts and technical solutions on the accelerator from source to extraction and show the construction progress.
	Slides THBI01 [6.375 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THBI01
About •	Received ※ 08 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 18 February 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRAI01	Developments and Prospects of FFAs at RAL	lattice, dynamic-aperture, controls, operation	351
	S. Machida STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Fixed Field Alternating Gradient Accelerator (FFA) has several advantages as a proton driver for high beam power applications. In particular, control of pulse structure can ben easily done by RF gymnastics. FFA is a sustainable (energy efficient) accelerator with the main magnets with DC operation. We will discuss the development of a FFA physics design for the ISIS (spallation neutron source) and its prototype.
	Slides FRAI01 [12.227 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAI01
About •	Received ※ 09 December 2022 — Revised ※ 08 February 2023 — Accepted ※ 03 March 2023 — Issue date ※ 16 May 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRAI02	Design of a 2 GeV Cyclotron with Constant Radial and Vertical Tunes	cyclotron, closed-orbit, betatron, proton	356
	T. Planche, R.A. Baartman TRIUMF, Vancouver, Canada
	Funding: This work was funded by TRIUMF which receives federal funding via a contribution agreement with the National Research Council of Canada. We demonstrate that a cyclotron can be made to have precisely constant betatron tunes over wide energy ranges. In particular, we show that the horizontal tune can be made constant and does not have to follow the Lorentz factor gamma, while still perfectly satisfying the isochronous condition. To make this demonstration we developed a technique based on the calculation of the betatron tunes entirely from the geometry of realistic non-hard-edge closed orbits. The technique is applied to the particular case of a 800 MeV to 2 GeV proton cyclotron to produce a design that is presented here.
	Slides FRAI02 [3.213 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAI02
About •	Received ※ 01 June 2023 — Revised ※ 28 January 2023 — Accepted ※ 09 July 2023 — Issue date ※ 12 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRAO02	Feasibility Study on 10 MW-Class Ultra-High Power Cyclotron	cyclotron, extraction, neutron, cavity	359
	T.J. Bian, S. An, F.P. Guan, L.Y. Ji, S.M. Wei CIAE, Beijing, People’s Republic of China
	10MW-class ultra-high power cyclotron (UHPC) has great application prospects in cutting-edge sciences, neutron source, advanced energy and advanced material, etc. So far, Cyclotron with average beam power of 10 MW still have some bottleneck problems. Beam energy and current of a high-power cyclotron is typically less than 800MeV and 3mA. In this paper, bottleneck problems of UHPC are analysed, and then a preliminary design of UHPC-10MW is presented.
	Slides FRAO02 [15.273 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAO02
About •	Received ※ 31 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 07 July 2023 — Issue date ※ 20 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

FRBO04	Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron	survey, cyclotron, coupling, site	381
	L.G. Zhang, R.A. Baartman, Y. Bylinskii, T. Planche, Y.-N. Rao TRIUMF, Vancouver, Canada
	Cyclotrons have a median plane symmetric structure. But the pole’s geometric error and the unevenly magnetized soft iron give rise to non-zero asymmetrical fields in the geometric median plane. The asymmetric field can shift the vertical position of the beam. Moreover, The error of the tilted median plane can be the driving force when the tunes pass through coupling resonances. In this paper, we take the TRIUMF 500 MeV cyclotron as an example to study the asymmetric field resulting from imperfect median plane symmetry. An approach due to M. Gordon, and a highly accurate compact finite differentiation method are used to investigate the historical field survey data, which reveals redundancy in the survey data. The redundancy was used in this study to correct the error in the measurement data. Further, the median plane asymmetry field could be manipulated using trim coils or harmonic coils with top and bottom coil currents in opposite directions (’Br-mode’). Using the created asymmetric field, we improved the vertical tune measurement method to investigate the linear coupling resonance in TRIUMF 500 MeV cyclotron. Eventually, the coupling resonance is corrected and avoided using the available harmonic coils and trim coils.
	Slides FRBO04 [1.620 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRBO04
About •	Received ※ 29 December 2022 — Revised ※ 07 February 2023 — Accepted ※ 10 February 2023 — Issue date ※ 10 July 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPO018

The Magnetic Field Design of a 16 MeV Variable Energy Cyclotron

cyclotron, extraction, simulation, magnet-design

103

Z. Wu, K.Z. Ding, J. Zhou
ASIPP, Hefei, People’s Republic of China
S. Xu
HFCIM, HeFei, People’s Republic of China

The development of a 16 MeV H⁻ cyclotron is in progress at CIM company (Hefei, China). Such machine is designed for radio-isotope production which is used for nuclear medicine. Beam extraction is ensured by means of stripper foils located at different radii to achieve variable extraction energy between 10 and 16 MeV. In this paper, the main magnet design was demonstrated in detail. An AVF magnet with four radial sectors was adopt to get strong axial focusing. The hill angular widths and hill gaps with radius were designed to meet the isochronous magnetic field. The tunes were optimized to avoid dangerous resonance. The result of magnet design was verified by beam dynamics simulations. After the presentation of the magnet design, some results on stripping extraction were also discussed. TOSCA (OPERA-3D) was used to perform 3D magnetic field simulation. An efficient beam simulation code developed by MATLAB was used to do beam dynamics simulations.

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-MOPO018

About •

Received ※ 12 February 2023 — Revised ※ 13 February 2023 — Accepted ※ 14 February 2023 — Issue date ※ 10 May 2023

Cite •

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

WEPO008

H^- Intra-Beam Stripping Loss Rate in Isochronous Cyclotron

cyclotron, linac, target, electron

219

Y.-N. Rao
TRIUMF, Vancouver, Canada

Funding: This work was funded by TRIUMF which receives federal funding via a contribution agreement with the National Research Council of Canada.
Binary collisions inside a H^- bunch result in H^- stripping and subsequent particle loss. This phenomenon, called intra-beam stripping, was observed in LEAR and SNS superconducting linac. We mimic the derivation made for the linac to derive the intra-beam stripping loss rate for an isochronous cyclotron. And then, we apply this theory to the TRIUMF 500 MeV H^- cyclotron to estimate the loss.

Poster WEPO008 [1.189 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-WEPO008

About •

Received ※ 05 December 2022 — Revised ※ 04 February 2023 — Accepted ※ 07 February 2023 — Issue date ※ 14 July 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

cyclotron, cavity, coupling, electron

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

cavity, cyclotron, extraction, proton

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)

THAO01

On the Energy Limit of Compact Isochronous Cyclotrons

cyclotron, hadrontherapy, focusing, hadron

255

W.J.G.M. Kleeven
IBA, Louvain-la-Neuve, Belgium

Existing analytical models for transverse beam dynamics in isochronous cyclotrons are often not valid or not precise for relativistic energies. The main difficulty in developing such models lies in the fact that cross-terms between derivatives of the average magnetic field and the azimuthally varying components cannot be neglected at higher energies. Taking such cross-terms rigorously into account results in an even larger number of terms that need to be included in the equations. In this paper, a method is developed which is relativistically correct and which provides results that are practical and easy to use. We derive new formulas, graphs, and tables for the radial and vertical tunes in terms of the flutter, its radial derivatives, the spiral angle and the relativistic gamma. Using this method, we study the 2nur=N structural resonance (N is number of sectors) and provide formulas and graphs for its stopband. Combining those equations with the new equation for the vertical tune, we find the stability zone and the energy limit of compact isochronous cyclotrons for any value of N. We confront the new analytical method with closed orbit simulations of the IBA C400 cyclotron for hadron therapy.

Slides THAO01 [6.641 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THAO01

About •

Received ※ 22 December 2022 — Revised ※ 05 February 2023 — Accepted ※ 07 February 2023 — Issue date ※ 02 April 2023

Cite •

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

THBI01

Status on NHa C400 Cyclotron for Hadrontherapy

cyclotron, extraction, proton, hadron

264

J. Mandrillon, M. Abs, P. Cailliau, S. Deprez, X. Donzel, G. Goosse, Y. Jongen, W.J.G.M. Kleeven, L.C.L. Koffel, V. Nuttens, Y. Otu, Y. Paradis
IBA, Louvain-la-Neuve, Belgium
O. Cosson, L. Maunoury, Ph. Velten
NHa, Caen, France

C400 is an isochronous cyclotron for cancer therapy delivering high dose rates of alphas to carbons at 400 MeV/amu extracted by electrostatic deflector and protons at 260 MeV extracted by stripping of molecular hydrogen. IBA started to pre-design the system more than 13 years ago in collaboration with JINR. The responsibility for the development of C400 has meanwhile been taken over by the French company Normandy Hadontherapy (NHa). However, the study and design work continued with a very strong involvement of IBA for the past 3 years, from concept on paper to reality. We will describe the most innovative concepts and technical solutions on the accelerator from source to extraction and show the construction progress.

Slides THBI01 [6.375 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-THBI01

About •

Received ※ 08 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 31 January 2023 — Issue date ※ 18 February 2023

Cite •

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

FRAI01

Developments and Prospects of FFAs at RAL

lattice, dynamic-aperture, controls, operation

351

S. Machida
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Fixed Field Alternating Gradient Accelerator (FFA) has several advantages as a proton driver for high beam power applications. In particular, control of pulse structure can ben easily done by RF gymnastics. FFA is a sustainable (energy efficient) accelerator with the main magnets with DC operation. We will discuss the development of a FFA physics design for the ISIS (spallation neutron source) and its prototype.

Slides FRAI01 [12.227 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAI01

About •

Received ※ 09 December 2022 — Revised ※ 08 February 2023 — Accepted ※ 03 March 2023 — Issue date ※ 16 May 2023

Cite •

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

FRAI02

Design of a 2 GeV Cyclotron with Constant Radial and Vertical Tunes

cyclotron, closed-orbit, betatron, proton

356

T. Planche, R.A. Baartman
TRIUMF, Vancouver, Canada

Funding: This work was funded by TRIUMF which receives federal funding via a contribution agreement with the National Research Council of Canada.
We demonstrate that a cyclotron can be made to have precisely constant betatron tunes over wide energy ranges. In particular, we show that the horizontal tune can be made constant and does not have to follow the Lorentz factor gamma, while still perfectly satisfying the isochronous condition. To make this demonstration we developed a technique based on the calculation of the betatron tunes entirely from the geometry of realistic non-hard-edge closed orbits. The technique is applied to the particular case of a 800 MeV to 2 GeV proton cyclotron to produce a design that is presented here.

Slides FRAI02 [3.213 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAI02

About •

Received ※ 01 June 2023 — Revised ※ 28 January 2023 — Accepted ※ 09 July 2023 — Issue date ※ 12 July 2023

Cite •

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

FRAO02

Feasibility Study on 10 MW-Class Ultra-High Power Cyclotron

cyclotron, extraction, neutron, cavity

359

T.J. Bian, S. An, F.P. Guan, L.Y. Ji, S.M. Wei
CIAE, Beijing, People’s Republic of China

10MW-class ultra-high power cyclotron (UHPC) has great application prospects in cutting-edge sciences, neutron source, advanced energy and advanced material, etc. So far, Cyclotron with average beam power of 10 MW still have some bottleneck problems. Beam energy and current of a high-power cyclotron is typically less than 800MeV and 3mA. In this paper, bottleneck problems of UHPC are analysed, and then a preliminary design of UHPC-10MW is presented.

Slides FRAO02 [15.273 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRAO02

About •

Received ※ 31 December 2022 — Revised ※ 12 January 2023 — Accepted ※ 07 July 2023 — Issue date ※ 20 July 2023

Cite •

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

FRBO04

Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron

survey, cyclotron, coupling, site

381

L.G. Zhang, R.A. Baartman, Y. Bylinskii, T. Planche, Y.-N. Rao
TRIUMF, Vancouver, Canada

Cyclotrons have a median plane symmetric structure. But the pole’s geometric error and the unevenly magnetized soft iron give rise to non-zero asymmetrical fields in the geometric median plane. The asymmetric field can shift the vertical position of the beam. Moreover, The error of the tilted median plane can be the driving force when the tunes pass through coupling resonances. In this paper, we take the TRIUMF 500 MeV cyclotron as an example to study the asymmetric field resulting from imperfect median plane symmetry. An approach due to M. Gordon, and a highly accurate compact finite differentiation method are used to investigate the historical field survey data, which reveals redundancy in the survey data. The redundancy was used in this study to correct the error in the measurement data. Further, the median plane asymmetry field could be manipulated using trim coils or harmonic coils with top and bottom coil currents in opposite directions (’Br-mode’). Using the created asymmetric field, we improved the vertical tune measurement method to investigate the linear coupling resonance in TRIUMF 500 MeV cyclotron. Eventually, the coupling resonance is corrected and avoided using the available harmonic coils and trim coils.

Slides FRBO04 [1.620 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-CYCLOTRONS2022-FRBO04

About •

Received ※ 29 December 2022 — Revised ※ 07 February 2023 — Accepted ※ 10 February 2023 — Issue date ※ 10 July 2023

Cite •

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