SAP2023 - List of Keywords (cavity)

Paper	Title	Other Keywords	Page
MOCYA01	Study of the Key Physics Problems in 10mA-class High Current Cyclotron	cyclotron, resonance, extraction, neutron	9
	T.J. Bian, S. An, F.P. Guan, L.Y. Ji, S.M. Wei CIAE, Beijing, People’s Republic of China
	Funding: National Natural Science Foundation of China (Grant No. 12105370) and the Scientific Research Program for Young Talent Elite Project of China National Nuclear Corporation (Grant No. FY212406000404). Proton beam with an average current of 10mA has many important applications in particle physics towards the intensity frontier, as well as in the advanced energy and material science. At present, superconducting linac is the mainstream of high current accelerator. As cyclotron has advantages of continuous beam structure, high beam/grid efficiency(60%~65% can be expected in superconducting ring cyclotron) and lower cost, cyclotron is also a potential candidate for future accelerator scheme with beam current of 10mA-class. Firstly, we will discuss the application prospect and motivation of 10mA-class high power cyclotron(10mA-HPC). Secondly, the key physics problems of 10mA-HPC are summarized, which includes strong space charge problems in low energy region, integer resonance crossing problems in high energy region and beam losses problems in extraction region. Thirdly, possible solutions for key physics problems and preliminary design of 10mA-HPC are proposed.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOCYA01
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 May 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB014	Development of a Vlasov Solver for Arbitrary Sub-optimal Lengthening Conditions in Double-RF System	synchrotron, coupling, impedance, betatron	34
	J.Y. Xu, N. Wang, H.S. Xu, Y. Zhang IHEP, Beijing, People’s Republic of China C.T. Lin IASF, Shenzhen, Guangdong, People’s Republic of China
	Solving Vlasov equation is a classic method for analyzing collective beam instabilities. Considering longitudinal impedance and the nonlinear longitudinal potential well, we developed a new Vlasov solver which can be used to study the transverse mode-coupling instability under the arbitrary sub-optimal lengthening and the optimal lengthening conditions in a double-RF system. Several different techniques to deal with the radial direction of longitudinal phase space have been tested. Numerical discretization method is selected in this paper. The development of the solver is presented in details here. Benchmarks and crosscheck of the solver have been made and presented as well.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB014
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 August 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB030	Physical Design of an S-Band Cold Cathode RF Gun	gun, cathode, electron, coupling	70
	T.H. He, H. Xu, K. Zhou, Z. Zhou CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
	In recent years, the properties of new field emission materials have been gradually improved with the advancement of materials research fields, which have provided the possibility for the research and realization of cold cathode RF guns. A 0.32+1 cell S-band RF gun was designed based on the emission properties of carbon nanotube films and ultra nano diamond films. This article mainly introduces the selection of electron gun cavity, RF design and corresponding thermal analysis. The physical design results basically meet the design requirements.
	Poster MOPB030 [1.010 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB030
About •	Received ※ 28 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 November 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPB034	Start to End Simulation for A Compact THz-FEL	electron, undulator, radiation, FEL	76
	R.Y. Luo, Q.S. Chen HUST, Wuhan, People’s Republic of China
	Funding: This work is supported by the National Natural Science Foundation of China(No.12175077) An oscillator type terahertz free electron laser (THz-FEL) is under construction at Huazhong University of Science and Technology (HUST). The designed electron beam energy ranges from 8 MeV to 14 MeV, and the radiation frequency ranges from 3 THz to 10 THz. FEL requires high quality electron beams of emittance, energy spread, bunch charge etc. To know the overall facility performance, a start to end simulation (from electron gun to the end of the oscillator) of the THz-FEL is performed. The simulation of the electron gun to the exit of the linac is performed using PARMELA, where the effect of space charge effects is considered. In addition, the effect of beam loading effect is considered for the linac. The transport line is matched and simulated using ELEGANT. GENESIS 1.3 and OPC is used for the lasing process. Results of the simulation are presented and discussed in this paper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB034
About •	Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 18 October 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB009	General Design of 180 MHz RFQ for BNCT	rfq, simulation, quadrupole, dipole	99
	Z.Q. Ren, Z. Li, W.L. Liao, P.T. Lin, X.B. Luo, X.J. Pu, X.M. Wan, Y.F. Yang SCU, Chengdu, People’s Republic of China
	Accelerator based boron neutron capture therapy (AB-BNCT) is a promising cancer treatment technology. An overall design have been proposed of a 180 MHz radio frequency quadrupole (RFQ) accelerator for BNCT. The particularity of dynamic design of the RFQ is that the average aperture radius changes along the accelerator. Beam dynamics design results show that the length of accelerator which accelerates protons from 35 keV to 2.81 MeV is 5.07 m, and the transmission up to 99.65%. In terms of radio frequency (RF) structure design, two shapes of cross section of cavity were simulated and compared, i.e., quadrilateral cavity and octagonal cavity. The results show that quadrilateral cavity performed better and was finally selected. Meanwhile, in order to keep the frequency of dipole mode away from the working quadrupole mode, 20 pairs of Pi-mode stabilizer rods are considered. The simulation results show that a large mode separation of more than 20MHz between the operating quadrupole mode and nearest dipole mode can be obtained, this is sufficient to deal with the errors caused by machining and misalignment.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB009
About •	Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 15 July 2023 — Issued ※ 24 July 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB012	Control of CAFe Beam Energy Using Linear Accelerator Simulation Software AVAS and Beam Line Calibration Technology	simulation, solenoid, cryomodule, operation	105
	C. Jin, C. Feng, Y. He, X. Qi, Z.J. Wang IMP/CAS, Lanzhou, People’s Republic of China
	A new accelerator simulation code named Advanced Virtual Accelerator Software (AVAS) was developed by the Institute of Modern Physics, Chinese Academy of Science. Although the code is proposed to simulate the particle transport in the linac of the China Initiative Accelerator Driven System (CiADS), it can be also used for common linacs. We have constructed a framework for the accelerator simulation program AVAS based on the structure, function, parameters, errors, and operational logic of real accelerators. The mapping relationship between the operating parame-ters and simulation parameters of the Chinese ADS Front-end Demo Linac (CAFe) superconducting sec-tion was successfully established through AVAS. In the testing experiment, AVAS successfully set the operat-ing parameters of the CAFe superconducting section, and the deviation between the energy setting value and the actual measurement value was about 0.5%.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB012
About •	Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 24 March 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB013	Multipole Field Optimization of X-Band High Gradient Structure	multipole, quadrupole, simulation, acceleration	108
	B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha TUB, Beijing, People’s Republic of China
	The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.
	Poster TUPB013 [0.350 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013
About •	Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOCYA01

Study of the Key Physics Problems in 10mA-class High Current Cyclotron

cyclotron, resonance, extraction, neutron

9

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

Funding: National Natural Science Foundation of China (Grant No. 12105370) and the Scientific Research Program for Young Talent Elite Project of China National Nuclear Corporation (Grant No. FY212406000404).
Proton beam with an average current of 10mA has many important applications in particle physics towards the intensity frontier, as well as in the advanced energy and material science. At present, superconducting linac is the mainstream of high current accelerator. As cyclotron has advantages of continuous beam structure, high beam/grid efficiency(60%~65% can be expected in superconducting ring cyclotron) and lower cost, cyclotron is also a potential candidate for future accelerator scheme with beam current of 10mA-class. Firstly, we will discuss the application prospect and motivation of 10mA-class high power cyclotron(10mA-HPC). Secondly, the key physics problems of 10mA-HPC are summarized, which includes strong space charge problems in low energy region, integer resonance crossing problems in high energy region and beam losses problems in extraction region. Thirdly, possible solutions for key physics problems and preliminary design of 10mA-HPC are proposed.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOCYA01

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 30 May 2024

Cite •

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

MOPB014

Development of a Vlasov Solver for Arbitrary Sub-optimal Lengthening Conditions in Double-RF System

synchrotron, coupling, impedance, betatron

34

J.Y. Xu, N. Wang, H.S. Xu, Y. Zhang
IHEP, Beijing, People’s Republic of China
C.T. Lin
IASF, Shenzhen, Guangdong, People’s Republic of China

Solving Vlasov equation is a classic method for analyzing collective beam instabilities. Considering longitudinal impedance and the nonlinear longitudinal potential well, we developed a new Vlasov solver which can be used to study the transverse mode-coupling instability under the arbitrary sub-optimal lengthening and the optimal lengthening conditions in a double-RF system. Several different techniques to deal with the radial direction of longitudinal phase space have been tested. Numerical discretization method is selected in this paper. The development of the solver is presented in details here. Benchmarks and crosscheck of the solver have been made and presented as well.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB014

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 August 2024

Cite •

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

MOPB030

Physical Design of an S-Band Cold Cathode RF Gun

gun, cathode, electron, coupling

70

T.H. He, H. Xu, K. Zhou, Z. Zhou
CAEP/IAE, Mianyang, Sichuan, People’s Republic of China

In recent years, the properties of new field emission materials have been gradually improved with the advancement of materials research fields, which have provided the possibility for the research and realization of cold cathode RF guns. A 0.32+1 cell S-band RF gun was designed based on the emission properties of carbon nanotube films and ultra nano diamond films. This article mainly introduces the selection of electron gun cavity, RF design and corresponding thermal analysis. The physical design results basically meet the design requirements.

Poster MOPB030 [1.010 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB030

About •

Received ※ 28 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 21 November 2023

Cite •

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

MOPB034

Start to End Simulation for A Compact THz-FEL

electron, undulator, radiation, FEL

76

R.Y. Luo, Q.S. Chen
HUST, Wuhan, People’s Republic of China

Funding: This work is supported by the National Natural Science Foundation of China(No.12175077)
An oscillator type terahertz free electron laser (THz-FEL) is under construction at Huazhong University of Science and Technology (HUST). The designed electron beam energy ranges from 8 MeV to 14 MeV, and the radiation frequency ranges from 3 THz to 10 THz. FEL requires high quality electron beams of emittance, energy spread, bunch charge etc. To know the overall facility performance, a start to end simulation (from electron gun to the end of the oscillator) of the THz-FEL is performed. The simulation of the electron gun to the exit of the linac is performed using PARMELA, where the effect of space charge effects is considered. In addition, the effect of beam loading effect is considered for the linac. The transport line is matched and simulated using ELEGANT. GENESIS 1.3 and OPC is used for the lasing process. Results of the simulation are presented and discussed in this paper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-MOPB034

About •

Received ※ 30 June 2023 — Revised ※ 08 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 18 October 2024

Cite •

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

TUPB009

General Design of 180 MHz RFQ for BNCT

rfq, simulation, quadrupole, dipole

99

Z.Q. Ren, Z. Li, W.L. Liao, P.T. Lin, X.B. Luo, X.J. Pu, X.M. Wan, Y.F. Yang
SCU, Chengdu, People’s Republic of China

Accelerator based boron neutron capture therapy (AB-BNCT) is a promising cancer treatment technology. An overall design have been proposed of a 180 MHz radio frequency quadrupole (RFQ) accelerator for BNCT. The particularity of dynamic design of the RFQ is that the average aperture radius changes along the accelerator. Beam dynamics design results show that the length of accelerator which accelerates protons from 35 keV to 2.81 MeV is 5.07 m, and the transmission up to 99.65%. In terms of radio frequency (RF) structure design, two shapes of cross section of cavity were simulated and compared, i.e., quadrilateral cavity and octagonal cavity. The results show that quadrilateral cavity performed better and was finally selected. Meanwhile, in order to keep the frequency of dipole mode away from the working quadrupole mode, 20 pairs of Pi-mode stabilizer rods are considered. The simulation results show that a large mode separation of more than 20MHz between the operating quadrupole mode and nearest dipole mode can be obtained, this is sufficient to deal with the errors caused by machining and misalignment.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB009

About •

Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 15 July 2023 — Issued ※ 24 July 2024

Cite •

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

TUPB012

Control of CAFe Beam Energy Using Linear Accelerator Simulation Software AVAS and Beam Line Calibration Technology

simulation, solenoid, cryomodule, operation

105

C. Jin, C. Feng, Y. He, X. Qi, Z.J. Wang
IMP/CAS, Lanzhou, People’s Republic of China

A new accelerator simulation code named Advanced Virtual Accelerator Software (AVAS) was developed by the Institute of Modern Physics, Chinese Academy of Science. Although the code is proposed to simulate the particle transport in the linac of the China Initiative Accelerator Driven System (CiADS), it can be also used for common linacs. We have constructed a framework for the accelerator simulation program AVAS based on the structure, function, parameters, errors, and operational logic of real accelerators. The mapping relationship between the operating parame-ters and simulation parameters of the Chinese ADS Front-end Demo Linac (CAFe) superconducting sec-tion was successfully established through AVAS. In the testing experiment, AVAS successfully set the operat-ing parameters of the CAFe superconducting section, and the deviation between the energy setting value and the actual measurement value was about 0.5%.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB012

About •

Received ※ 30 June 2023 — Revised ※ 09 July 2023 — Accepted ※ 11 July 2023 — Issued ※ 24 March 2024

Cite •

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

TUPB013

Multipole Field Optimization of X-Band High Gradient Structure

multipole, quadrupole, simulation, acceleration

108

B.Y. Feng, H.B. Chen, Q. Gao, X. Lin, J.R. Shi, H. Zha
TUB, Beijing, People’s Republic of China

The X-band constant gradient acceleration structure plays a crucial role in the VIGAS project. However, the presence of a multipole field component in the struc-ture’s coupler leads to an increase in ray bandwidth and a decrease in yield, ultimately affecting the quality of the generated rays. Through calculations, it has been determined that the quadrupole field component is particularly prominent in the original structure, ac-counting for 29.5% of the fundamental mode strength. Therefore, it is necessary to modify the cavity struc-ture of the coupler. By altering the shape of the cavity to two staggered circles, the objective of reducing the quadrupole field is achieved. The optimized quadru-pole field component now accounts for approximately 0.3% of the fundamental mode strength. Subsequently, the non-resonant perturbation method was employed to simulate and experimentally measure the magnitude of the multipole field component in the actual acceler-ation cavity.

Poster TUPB013 [0.350 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB013

About •

Received ※ 30 June 2023 — Accepted ※ 11 July 2023 — Issued ※ 27 September 2024

Cite •

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