IBIC2021 - List of Authors (Suwada, T.)

Paper	Title	Page
MOPP10	Observation of Wakefield Effects with Wideband Feedthrough-BPM at the Positron Capture Section of the SuperKEKB Injector Linac	52
	M.A. Rehman, T. Suwada KEK, Ibaraki, Japan
	At the SuperKEKB injector linac, positrons are generated by striking electron beam at tungsten target. The secondary electrons are also produced during positron creation and accelerated in the positron capture section. A new wideband feedthrough-beam position monitor (BPM) system was developed for synchronous detection of secondary produced e^- and e⁺ beams with temporal separation of about 180 ps. When e⁺/e⁻ bunches pass through the accelerating structure or vacuum duct of different radius, they generate wakefields. These wakefields can be directly observed with the feedthrough-BPM. A simulation study has also been carried to validate the observed wakefield effects with the feedthrough-BPM. The effects of wakefields on beam parameters will be reported in this paper.
	Poster MOPP10 [1.316 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2021-MOPP10
About •	paper received ※ 06 September 2021 paper accepted ※ 15 September 2021 issue date ※ 10 October 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP12	Modal Analysis of Electromagnetic Coupling Between SMA-Feedthrough Electrode and Beam for Wideband Beam Monitor	392
	T. Suwada KEK, Ibaraki, Japan
	The direct simultaneous detection of electron (e-) and positron (e+) bunch signals was successfully performed for the first time by a wideband beam monitor at the positron capture section of the SuperKEKB factory. This monitor can measure a time interval between the e^- and e⁺ bunches, their bunch lengths, bunch intensities, and transverse beam positions, depending on the phase of accelerating structures. For this purpose, a new beam monitor with wideband pickups simply using SMA feedthroughs and a wideband detection system based on a fast and real-time oscilloscope was developed to investigate their capture process at the capture section and to maximally optimize the e⁺ intensity. The required specification for the new monitor is to simultaneously detect the e⁺ and e^- bunches generated in the capture section within the resolution of pico-second level with a sufficient dynamic range in the time-interval and bunch-length measurements. Thus, the wideband detection system is required for this purpose. In this report, the basic design and results based on a modal analysis of electromagnetic couplings between the SMA-feedthrough electrode and a beam are in detail given along with some obtained performance.
	Poster WEPP12 [3.714 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2021-WEPP12
About •	paper received ※ 04 September 2021 paper accepted ※ 27 September 2021 issue date ※ 08 October 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Observation of Wakefield Effects with Wideband Feedthrough-BPM at the Positron Capture Section of the SuperKEKB Injector Linac

52

M.A. Rehman, T. Suwada
KEK, Ibaraki, Japan

At the SuperKEKB injector linac, positrons are generated by striking electron beam at tungsten target. The secondary electrons are also produced during positron creation and accelerated in the positron capture section. A new wideband feedthrough-beam position monitor (BPM) system was developed for synchronous detection of secondary produced e^- and e⁺ beams with temporal separation of about 180 ps. When e⁺/e⁻ bunches pass through the accelerating structure or vacuum duct of different radius, they generate wakefields. These wakefields can be directly observed with the feedthrough-BPM. A simulation study has also been carried to validate the observed wakefield effects with the feedthrough-BPM. The effects of wakefields on beam parameters will be reported in this paper.

Poster MOPP10 [1.316 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2021-MOPP10

About •

paper received ※ 06 September 2021 paper accepted ※ 15 September 2021 issue date ※ 10 October 2021

Export •

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

WEPP12

Modal Analysis of Electromagnetic Coupling Between SMA-Feedthrough Electrode and Beam for Wideband Beam Monitor

392

T. Suwada
KEK, Ibaraki, Japan

The direct simultaneous detection of electron (e-) and positron (e+) bunch signals was successfully performed for the first time by a wideband beam monitor at the positron capture section of the SuperKEKB factory. This monitor can measure a time interval between the e^- and e⁺ bunches, their bunch lengths, bunch intensities, and transverse beam positions, depending on the phase of accelerating structures. For this purpose, a new beam monitor with wideband pickups simply using SMA feedthroughs and a wideband detection system based on a fast and real-time oscilloscope was developed to investigate their capture process at the capture section and to maximally optimize the e⁺ intensity. The required specification for the new monitor is to simultaneously detect the e⁺ and e^- bunches generated in the capture section within the resolution of pico-second level with a sufficient dynamic range in the time-interval and bunch-length measurements. Thus, the wideband detection system is required for this purpose. In this report, the basic design and results based on a modal analysis of electromagnetic couplings between the SMA-feedthrough electrode and a beam are in detail given along with some obtained performance.

Poster WEPP12 [3.714 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2021-WEPP12

About •

paper received ※ 04 September 2021 paper accepted ※ 27 September 2021 issue date ※ 08 October 2021

Export •

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