IBIC2019 - List of Keywords (impedance)

Paper	Title	Other Keywords	Page
MOPP010	Design and Properties of a New DCCT Chamber for the PF-Ring at KEK	simulation, operation, HOM, cavity	91
	R. Takai, T. Honda, T. Nogami, T. Obina, Y. Tanimoto KEK, Ibaraki, Japan
	A DC current transformer (DCCT) for the PF-ring was renewed during the 2018 summer shutdown. A vacuum chamber for the new DCCT was designed based on a circular duct with an inner diameter of 100 mm and has a structure housing a toroidal core inside of electromagnetic shields. The geometry of the ceramic break for interrupting the wall current flow was optimized using a three-dimensional electromagnetic field simulator, and the break was fabricated considering some technical limitations. Both ends of the ceramic break were short-circuited in a high-frequency manner by a sheet-like capacitive structure to suppress the radiation of unneeded higher-order modes (HOMs) into the core housing. The ceramic break is also equipped with water-cooling pipes on metal sleeves brazed to the both ends to efficiently remove the heat generated by HOMs. The new DCCT chamber has been used already in user operation without any problems. A temperature rise near the ceramic break is still approximately six degrees Celsius, even when a 50-mA isolated bunch is stored.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP010
About •	paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP020	Development of a Gated IPM System for J-PARC MR	electron, detector, operation, GUI	343
	K. Satou J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	In the Main Ring (MR) of Japan Proton Accelerator Research Complex (J-PARC), a residual-gas ionization profile monitor (IPM) is used to measure bunched beam profiles. After injection, the beam widths of the first ~20 bunched beams are analysed to correct the Quadruple oscillation. While only a few dozen profiles are required for this correction, the present IPM auto-matically measures all bunched beams, more than 2·10⁶ bunches from injection to the extraction, because the present IPM operates using DC. This system is unde-sirable due to the limited lifetime of the Micro Channel Plate (MCP) detector; the more particles the MCP senses, the more it loses gain flatness and thus lifetime. To improve this situation, a gated IPM system has been developed, in which the High Voltage (HV) is operated in pulse mode. Results of performance analysis of a new HV power supply, improvement of the electrodes, and particle-tracking simulation considering the space-charge-electric field of the bunched beam are de-scribed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP020
About •	paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPP021	Development of 16 Electrodes Beam-size Monitors for J-PARC MR	emittance, quadrupole, proton, operation	347
	M. Tajima, T. Nakaya Kyoto University, Kyoto, Japan T. Koseki, T. Toyama KEK, Tokai, Ibaraki, Japan
	For J-PARC, 16 electrodes beam-monitors are developed. It is possible to measure the transverse moments of beams from the induced voltages. A beam size is calculated from these in two locations with different values of beta functions. Beam-monitors such as a Flying Wire Monitor and an Ionization Profile Monitor (IPM) are already installed. However, the two monitors have issues in measuring higher intensity beams. The former is that the wire gets easily burned out and the latter is that there is a sign of the saturation by a space charge effect. Therefore, these aim at measuring the sizes of high intensity proton beams up to 4.2·10⁺¹³ protons/bunch, which corresponds to 1.3 MW in 1.16 s cycle operation of the MR. Furthermore, with high accuracy measurements, the injection mismatch from the RCS is to be decreased. In the beam test in February 2019, the signal-noise ratio (SNR) of this monitor in bunch-by-bunch measurements was nearly 40 dB and lower than the SNR > 50 dB which is comparable to IPM. To improve the SNR, we developed new LPFs for anti-aliasing and improved signal processing. In addition, the second monitor will be installed in August 2019 and tested with beams in November.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP021
About •	paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP003	A new button-type beam position monitor for BESSY II and BESSY VSR	vacuum, operation, storage-ring, resonance	508
	J.G. Hwang, V. Dürr, F. Falkenstern, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk HZB, Berlin, Germany
	Funding: This work was supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association. The future BESSY VSR system involves more than one order-of-magnitude differences in the total charge of adjacent short and long bunches within the bunch train. Thus, any signal ringing beyond a nanosecond in time will cause a misreading of beam position and current, specifically for low bunch charges. This calls for improved performance for the bunch-selective operation of the beam-position-monitor (BPM) system. We report on the corresponding design and fabrication of a new button BPM with advanced features, such as impedance matching inside the button as well as optimization of insulator material, button size, and position, for reduced crosstalk between buttons.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP003
About •	paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP004	Concept of a Beam Diagnostics System for the Multi-Turn ERL Operation at the S-DALINAC	cavity, linac, operation, recirculation	513
	M. Dutine, M. Arnold, T. Bahlo, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, M. Steinhorst TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by BMBF through grant No. 05H18RDRB2 and DFG through GRK 2128. The S-DALINAC* is a thrice-recirculating linear electron accelerator operating in cw-mode at a frequency of 3 GHz. A path-length adjustment system in the second recirculation beam line allows to shift the beam phase by 360° and thus to operate in ERL mode. For the multi-turn ERL operation, the beam will be accelerated twice and subsequently decelerated twice again (not demonstrated yet). For this mode, it is necessary to develop a nondestructive beam diagnostics system in order to measure the beam position, phase and beam current of both, the accelerated and the decelerated beam, simultaneously in the same beamline. A particular challenge will be the operation at low beam currents of 100 nA, which corresponds to bunch charges of about 30 aC. The conceptional study of a 6 GHz resonant cavity beam position monitor will be presented together with alternative solutions. * N. Pietralla, Nuclear Physics News, Vol. 28, No. 2, 4 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP004
About •	paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP007	Calibration for Beam Energy Position Monitor System for Riken Superconducting Acceleration Cavity	network, linac, vacuum, quadrupole	526
	T. Watanabe, M. Fujimaki, N. Fukunishi, H. Imao, O. Kamigaito, N. Sakamoto, Y. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan K. Hanamura, T. Kawachi Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan A. Kamoshida National Instruments Japan Corporation, MInato-ku, Tokyo, Japan R. Koyama SHI Accelerator Service Ltd., Tokyo, Japan A. Miura JAEA/J-PARC, Tokai-mura, Japan T. Miyao, T. Toyama KEK, Ibaraki, Japan
	Upgrades for the RIKEN Heavy-ion Linac (RILAC) involving a new Superconducting Linac (SRILAC) are currently underway to promote super-heavy element searches and Radio Isotope (RI) production (211At) for medical use at the RIKEN radioactive isotope beam factory (RIBF). If destructive monitors are used, since they generate outgassing, it becomes difficult to maintain the Q value and surface resistance indicating the performance of the superconducting radio frequency (SRF) cavities over a long period of time. Therefore it is crucially important to develop nondestructive beam measurement diagnostics. We have developed a beam energy position monitor (BEPM) system which can measure not only the beam position but also the beam energy simultaneously by measuring the time of flight of the beam. By using parabolic cut, ideal linear response of the quadrupole moments is realized, keeping a good linear position sensitivity at the same time. We fabricated 11 BEPMs and the position calibration system employing a wire method has been used to obtain the sensitivity and offset of BEPMs. We will describe details concerning the BEPM, calibration system and measured results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP007
About •	paper received ※ 05 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP010	Design and Simulation of a Cavity BPM for HUST Proton Therapy Facility	cavity, proton, coupling, simulation	530
	J.Q. Li, Q.S. Chen, K. Tang, P. Tian HUST, Wuhan, People’s Republic of China K. Fan Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
	In proton therapy facility, non-destructive beam diagnostic devices are essential for on-line measurement during the patient treatment. To meet the clinical requirement, the beam current becomes ultra-low of the order of nano-ampere, which is a great challenge to non-destructive beam diagnostics because of the extremely low signal level. Compared with conventional non-destructive beam diagnostic devices, the cavity beam position monitor (BPM) has a high shunt impedance to get enough power levels, so a cavity BPM system is designed for HUST-PTF. It is made up of two resonant cavities called reference cavity and position cavity, respectively. Both cavities are simulated and optimized by CST Microwave Studio and Particle Studio. Finally, the electronics of cavity BPM we plan to use is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP010
About •	paper received ※ 03 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP014	A Report on Developments of the BCM and BPM Pickups of the ESS MEBT	MEBT, pick-up, quadrupole, vacuum	539
	S. Varnasseri, I. Bustinduy, A. Conde, J. Martin, A. Ortega, I. Rueda, A.Z. Zugazaga ESS Bilbao, Zamudio, Spain R.A. Baron, H. Hassanzadegan, T.J. Shea ESS, Lund, Sweden
	In the framework of the Spanish In-Kind Contribution (IKC) to the construction of the European Spallation Source (ESS-ERIC), ESS-Bilbao is in charge of providing some key systems for the accelerator. In this paper, design and pre-delivery measurements of non-interceptive devices of MEBT (e.g Beam Position Monitor pick-ups, shielded ACCT and FCT) are reported. Overall there are 8 BPMs distributed in MEBT, which 7 of them are used for the beam position and phase measurements and one BPM is used for the fast timing characterization. The latter is used mainly to characterize the partially chopped bunches and rise/fall time of the Beam Chopper. Furthermore there are two ACCTs, one just attached to the beam dump and the other at the last raft of the MEBT. One FCT combined with the second ACCT gives the complementary information on the fast timing characteristics of the beam pulses.
	Poster WEPP014 [1.291 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP014
About •	paper received ※ 02 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP022	A Method of Correcting the Beam Transverse Offset for the Cavity Bunch Length Monitor	cavity, simulation, dipole, free-electron-laser	572
	Q. Wang, Q. Luo, B.G. Sun USTC/NSRL, Hefei, Anhui, People’s Republic of China
	Funding: Supported by National Key R&D Program of China (Grant No. 2016YFA0401900 and No. 2016YFA0401903) and The National Natural Science Foundation of China (Grant No. U1832169 and No. 11575181) Cavity bunch length monitor uses monopole modes excited by bunches within the cavities to measure the bunch longitudinal root mean square (rms) length. It can provide a very high accuracy and high resolution. However, when the bunch passes through the cavities with transverse offset (that is, the bunch moves off the cavity axis), the amplitude of the monopole modes will change and cannot reflect the bunch length precisely. In this paper, a method of correcting the beam transverse offset is proposed. Simulation results show that the method can reduce the error of the bunch length measurement significantly.
	Poster WEPP022 [0.735 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP022
About •	paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPP010

Design and Properties of a New DCCT Chamber for the PF-Ring at KEK

simulation, operation, HOM, cavity

91

R. Takai, T. Honda, T. Nogami, T. Obina, Y. Tanimoto
KEK, Ibaraki, Japan

A DC current transformer (DCCT) for the PF-ring was renewed during the 2018 summer shutdown. A vacuum chamber for the new DCCT was designed based on a circular duct with an inner diameter of 100 mm and has a structure housing a toroidal core inside of electromagnetic shields. The geometry of the ceramic break for interrupting the wall current flow was optimized using a three-dimensional electromagnetic field simulator, and the break was fabricated considering some technical limitations. Both ends of the ceramic break were short-circuited in a high-frequency manner by a sheet-like capacitive structure to suppress the radiation of unneeded higher-order modes (HOMs) into the core housing. The ceramic break is also equipped with water-cooling pipes on metal sleeves brazed to the both ends to efficiently remove the heat generated by HOMs. The new DCCT chamber has been used already in user operation without any problems. A temperature rise near the ceramic break is still approximately six degrees Celsius, even when a 50-mA isolated bunch is stored.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP010

About •

paper received ※ 04 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP020

Development of a Gated IPM System for J-PARC MR

electron, detector, operation, GUI

343

K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

In the Main Ring (MR) of Japan Proton Accelerator Research Complex (J-PARC), a residual-gas ionization profile monitor (IPM) is used to measure bunched beam profiles. After injection, the beam widths of the first ~20 bunched beams are analysed to correct the Quadruple oscillation. While only a few dozen profiles are required for this correction, the present IPM auto-matically measures all bunched beams, more than 2·10⁶ bunches from injection to the extraction, because the present IPM operates using DC. This system is unde-sirable due to the limited lifetime of the Micro Channel Plate (MCP) detector; the more particles the MCP senses, the more it loses gain flatness and thus lifetime. To improve this situation, a gated IPM system has been developed, in which the High Voltage (HV) is operated in pulse mode. Results of performance analysis of a new HV power supply, improvement of the electrodes, and particle-tracking simulation considering the space-charge-electric field of the bunched beam are de-scribed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP020

About •

paper received ※ 04 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

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

TUPP021

Development of 16 Electrodes Beam-size Monitors for J-PARC MR

emittance, quadrupole, proton, operation

347

M. Tajima, T. Nakaya
Kyoto University, Kyoto, Japan
T. Koseki, T. Toyama
KEK, Tokai, Ibaraki, Japan

For J-PARC, 16 electrodes beam-monitors are developed. It is possible to measure the transverse moments of beams from the induced voltages. A beam size is calculated from these in two locations with different values of beta functions. Beam-monitors such as a Flying Wire Monitor and an Ionization Profile Monitor (IPM) are already installed. However, the two monitors have issues in measuring higher intensity beams. The former is that the wire gets easily burned out and the latter is that there is a sign of the saturation by a space charge effect. Therefore, these aim at measuring the sizes of high intensity proton beams up to 4.2·10⁺¹³ protons/bunch, which corresponds to 1.3 MW in 1.16 s cycle operation of the MR. Furthermore, with high accuracy measurements, the injection mismatch from the RCS is to be decreased. In the beam test in February 2019, the signal-noise ratio (SNR) of this monitor in bunch-by-bunch measurements was nearly 40 dB and lower than the SNR > 50 dB which is comparable to IPM. To improve the SNR, we developed new LPFs for anti-aliasing and improved signal processing. In addition, the second monitor will be installed in August 2019 and tested with beams in November.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP021

About •

paper received ※ 04 September 2019 paper accepted ※ 09 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP003

A new button-type beam position monitor for BESSY II and BESSY VSR

vacuum, operation, storage-ring, resonance

508

J.G. Hwang, V. Dürr, F. Falkenstern, M. Ries, A. Schälicke, G. Schiwietz, D. Wolk
HZB, Berlin, Germany

Funding: This work was supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association.
The future BESSY VSR system involves more than one order-of-magnitude differences in the total charge of adjacent short and long bunches within the bunch train. Thus, any signal ringing beyond a nanosecond in time will cause a misreading of beam position and current, specifically for low bunch charges. This calls for improved performance for the bunch-selective operation of the beam-position-monitor (BPM) system. We report on the corresponding design and fabrication of a new button BPM with advanced features, such as impedance matching inside the button as well as optimization of insulator material, button size, and position, for reduced crosstalk between buttons.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP003

About •

paper received ※ 04 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP004

Concept of a Beam Diagnostics System for the Multi-Turn ERL Operation at the S-DALINAC

cavity, linac, operation, recirculation

513

M. Dutine, M. Arnold, T. Bahlo, R. Grewe, L.E. Jürgensen, N. Pietralla, F. Schließmann, M. Steinhorst
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by BMBF through grant No. 05H18RDRB2 and DFG through GRK 2128.
The S-DALINAC* is a thrice-recirculating linear electron accelerator operating in cw-mode at a frequency of 3 GHz. A path-length adjustment system in the second recirculation beam line allows to shift the beam phase by 360° and thus to operate in ERL mode. For the multi-turn ERL operation, the beam will be accelerated twice and subsequently decelerated twice again (not demonstrated yet). For this mode, it is necessary to develop a nondestructive beam diagnostics system in order to measure the beam position, phase and beam current of both, the accelerated and the decelerated beam, simultaneously in the same beamline. A particular challenge will be the operation at low beam currents of 100 nA, which corresponds to bunch charges of about 30 aC. The conceptional study of a 6 GHz resonant cavity beam position monitor will be presented together with alternative solutions.
* N. Pietralla, Nuclear Physics News, Vol. 28, No. 2, 4 (2018)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP004

About •

paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP007

Calibration for Beam Energy Position Monitor System for Riken Superconducting Acceleration Cavity

network, linac, vacuum, quadrupole

526

T. Watanabe, M. Fujimaki, N. Fukunishi, H. Imao, O. Kamigaito, N. Sakamoto, Y. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan
K. Hanamura, T. Kawachi
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
A. Kamoshida
National Instruments Japan Corporation, MInato-ku, Tokyo, Japan
R. Koyama
SHI Accelerator Service Ltd., Tokyo, Japan
A. Miura
JAEA/J-PARC, Tokai-mura, Japan
T. Miyao, T. Toyama
KEK, Ibaraki, Japan

Upgrades for the RIKEN Heavy-ion Linac (RILAC) involving a new Superconducting Linac (SRILAC) are currently underway to promote super-heavy element searches and Radio Isotope (RI) production (211At) for medical use at the RIKEN radioactive isotope beam factory (RIBF). If destructive monitors are used, since they generate outgassing, it becomes difficult to maintain the Q value and surface resistance indicating the performance of the superconducting radio frequency (SRF) cavities over a long period of time. Therefore it is crucially important to develop nondestructive beam measurement diagnostics. We have developed a beam energy position monitor (BEPM) system which can measure not only the beam position but also the beam energy simultaneously by measuring the time of flight of the beam. By using parabolic cut, ideal linear response of the quadrupole moments is realized, keeping a good linear position sensitivity at the same time. We fabricated 11 BEPMs and the position calibration system employing a wire method has been used to obtain the sensitivity and offset of BEPMs. We will describe details concerning the BEPM, calibration system and measured results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP007

About •

paper received ※ 05 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP010

Design and Simulation of a Cavity BPM for HUST Proton Therapy Facility

cavity, proton, coupling, simulation

530

J.Q. Li, Q.S. Chen, K. Tang, P. Tian
HUST, Wuhan, People’s Republic of China
K. Fan
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China

In proton therapy facility, non-destructive beam diagnostic devices are essential for on-line measurement during the patient treatment. To meet the clinical requirement, the beam current becomes ultra-low of the order of nano-ampere, which is a great challenge to non-destructive beam diagnostics because of the extremely low signal level. Compared with conventional non-destructive beam diagnostic devices, the cavity beam position monitor (BPM) has a high shunt impedance to get enough power levels, so a cavity BPM system is designed for HUST-PTF. It is made up of two resonant cavities called reference cavity and position cavity, respectively. Both cavities are simulated and optimized by CST Microwave Studio and Particle Studio. Finally, the electronics of cavity BPM we plan to use is shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP010

About •

paper received ※ 03 September 2019 paper accepted ※ 07 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP014

A Report on Developments of the BCM and BPM Pickups of the ESS MEBT

MEBT, pick-up, quadrupole, vacuum

539

S. Varnasseri, I. Bustinduy, A. Conde, J. Martin, A. Ortega, I. Rueda, A.Z. Zugazaga
ESS Bilbao, Zamudio, Spain
R.A. Baron, H. Hassanzadegan, T.J. Shea
ESS, Lund, Sweden

In the framework of the Spanish In-Kind Contribution (IKC) to the construction of the European Spallation Source (ESS-ERIC), ESS-Bilbao is in charge of providing some key systems for the accelerator. In this paper, design and pre-delivery measurements of non-interceptive devices of MEBT (e.g Beam Position Monitor pick-ups, shielded ACCT and FCT) are reported. Overall there are 8 BPMs distributed in MEBT, which 7 of them are used for the beam position and phase measurements and one BPM is used for the fast timing characterization. The latter is used mainly to characterize the partially chopped bunches and rise/fall time of the Beam Chopper. Furthermore there are two ACCTs, one just attached to the beam dump and the other at the last raft of the MEBT. One FCT combined with the second ACCT gives the complementary information on the fast timing characteristics of the beam pulses.

Poster WEPP014 [1.291 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP014

About •

paper received ※ 02 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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

WEPP022

A Method of Correcting the Beam Transverse Offset for the Cavity Bunch Length Monitor

cavity, simulation, dipole, free-electron-laser

572

Q. Wang, Q. Luo, B.G. Sun
USTC/NSRL, Hefei, Anhui, People’s Republic of China

Funding: Supported by National Key R&D Program of China (Grant No. 2016YFA0401900 and No. 2016YFA0401903) and The National Natural Science Foundation of China (Grant No. U1832169 and No. 11575181)
Cavity bunch length monitor uses monopole modes excited by bunches within the cavities to measure the bunch longitudinal root mean square (rms) length. It can provide a very high accuracy and high resolution. However, when the bunch passes through the cavities with transverse offset (that is, the bunch moves off the cavity axis), the amplitude of the monopole modes will change and cannot reflect the bunch length precisely. In this paper, a method of correcting the beam transverse offset is proposed. Simulation results show that the method can reduce the error of the bunch length measurement significantly.

Poster WEPP022 [0.735 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP022

About •

paper received ※ 03 September 2019 paper accepted ※ 10 September 2019 issue date ※ 10 November 2019

Export •

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