IBIC2016 - List of Keywords (resonance)

Paper	Title	Other Keywords	Page
MOPG43	Beam Tuning for Longitudinal Profile at J-PARC Linac	emittance, linac, quadrupole, DTL	150
	A. Miura JAEA/J-PARC, Tokai-mura, Japan Y. Liu, T. Maruta KEK/JAEA, Ibaraki-Ken, Japan T. Miyao KEK, Ibaraki, Japan
	Using bunch shape monitors (BSMs), we measured the longitudinal bunch lengths of negative hydrogen ion beams in the J-PARC linac. A BSM was installed between two linacs, separate-type drift tube linac (SDTL) and an annular-ring-coupled structure linac (ACS), having acceleration frequencies of 324 and 972 MHz, respectively. We used radio-frequency amplitude modulation of bunches in the beam transport between the SDTL and ACS to minimize emittance growth and beam loss. We conducted amplitude scanning and compared the results with the twiss-parameters obtained from the transverse profiles. In this paper, we discuss the results of amplitude tuning of the buncher cavity at the point of beam loss and emittance. We also discuss the measurement results for various equipartitioning settings of quadrupole magnets.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG43
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TUPG12	Design for the Diamond Longitudinal Bunch-by-Bunch Feedback Cavity	cavity, impedance, HOM, coupling	340
	A.F.D. Morgan, G. Rehm DLS, Oxfordshire, United Kingdom
	In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. In order to deal with the potential higher order modes in these we are designing a longitudinal bunch-by-bunch feedback system. This paper will focus on the design of the overloaded cavity kicker, adapted to the Diamond beam pipe cross section. The design has evolved in order to reduce the strong 3rd harmonic resonance seen on the introduction of the racetrack beam pipe. Through a combination of geometry optimisation and the addition of integrated taper transitions this harmonic has been greatly reduced while also minimising sharp resonances below 15GHz. The major features will be described, as well as the expected performance parameters.
	Poster TUPG12 [1.423 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG12
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TUPG18	Design Optimization of Button-Type BPM Electrode for the SPring-8 Upgrade	impedance, simulation, storage-ring, vacuum	360
	M. Masaki, H. Dewa, T. Fujita, S. Takano JASRI, Hyogo, Japan H. Maesaka, S. Takano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	The requirements for a BPM system for the SPring-8 upgrade are long-term stability, sufficient signal intensity and high accuracy. The design of a button-type electrode for the BPM has been optimized from the perspectives of 1) mechanical structure, 2) rf characteristics, 3) thermal issue. We have adopted the electrode structure without a sleeve enclosing the button to maximize the button diameter for the narrow aperture of the vacuum chamber. The absence of an annular slot around the sleeve in a lodging hole for the electrode eliminates the associated beam impedance. To minimize the beam impedance and the trapped mode heating of the electrode, the rf structure has been optimized by 3D electro-magnetic simulations. To suppress the ohmic loss on the button and center pin thermally isolated from the water cooled BPM block, we have selected molybdenum as a material with high electric and thermal conductivities. The reduction of the heating suppresses thermal deformation of the electrode and the BPM block, and improves thermal stability of the BPM system. The mechanical tolerance of the electrode was defined to fit the error budget for the total BPM offset error of 0.1 mm rms. H. Maesaka et al., in this conference.
	Poster TUPG18 [1.104 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG18
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WECL03	Measurement of the Beam Response to Quadrupole Kick by Using Stripline Pickup Monitor at J-PARC Main Ring	kicker, quadrupole, betatron, operation	604
	Y. Nakanishi, A. Ichikawa, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya Kyoto University, Kyoto, Japan T. Koseki, H. Kuboki, M. Okada, T. Toyama KEK, Tokai, Ibaraki, Japan
	Funding: Work supported by MEXT KAKENHI, GA 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier" In high intensity proton synchrotrons, linear and nonlinear betatron resonances cause beam loss. When the betatron tune spreads over a resonance line, the oscillation amplitude will get larger, causing a large beam loss. Our study aims for a direct measurement of the betatron tune spread by using a quadrupole kicker and a 4-electrode monitor. The monochromatic rf signal is inputted to the kicker and we induce an oscillation by kicking the beam. The amplitude of the quadrupole oscillation will depend on the number of particles having a certain tune. In the beam test at J-PARC MR, the dipole kicker was used as a quadrupole kicker by exciting the two facing electrodes in-phase. We measured the response to the kick at several frequencies. We observed that the amplitude depends on the kicker frequency and the number of particles per bunch. This demonstrates that the quadrupole oscillation can be induced by a kicker and the possibility of measuring the number of a particular tune particle from the response. We will present the result of the beam test and our prospect and the comparison between the experimental result and a numerical calculation.
	Slides WECL03 [2.054 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WECL03
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WEPG32	First Heating with the European XFEL Laser Heater	laser, electron, undulator, interaction-region	694
	M. Hamberg Uppsala University, Uppsala, Sweden F. Brinker, M. Scholz DESY, Hamburg, Germany
	Funding: DESY and Swedish Research council The European XFEL is a 3.4 km long free-electron laser (FEL) which will deliver radiation in the wavelength regime of 0.05 to 4.7 nm. To avoid problems with longitudinal microbunching instabilities a laser heater is implemented. It heats up the electron bunches which will improve the overall brightness level of the FEL. I report the commissioning steps undertaken and the first recorded heating outputs observed in the injector section.
	Poster WEPG32 [2.322 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG32
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WEPG41	Measurement of Coupling Impedances using a Goubau Line	impedance, simulation, coupling, scattering	719
	F. Stulle, J.F. Bergoz BERGOZ Instrumentation, Saint Genis Pouilly, France H.-W. Glock HZB, Berlin, Germany
	Longitudinal coupling impedances can be deduced from S-Parameter measurements performed on a Goubau Line. The Goubau Line, also known as single wire line, is a variant of the coaxial wire method. Both setups use a wire for mimicking the particle beam. Coaxial tapers at the wire ends adapt wave impedance to the 50ohm impedance of coaxial cables, sources and receivers. But for guiding the electromagnetic wave, the Goubau Line relies on the realistic boundary conditions imposed by an insulated wire instead of using a coaxial shield. Equations for the deduction of longitudinal coupling impedances are reviewed and applied to Goubau Line measurements. Goubau Line measurements and CST Studio simulations are compared, showing good agreement.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG41
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPG43

Beam Tuning for Longitudinal Profile at J-PARC Linac

emittance, linac, quadrupole, DTL

150

A. Miura
JAEA/J-PARC, Tokai-mura, Japan
Y. Liu, T. Maruta
KEK/JAEA, Ibaraki-Ken, Japan
T. Miyao
KEK, Ibaraki, Japan

Using bunch shape monitors (BSMs), we measured the longitudinal bunch lengths of negative hydrogen ion beams in the J-PARC linac. A BSM was installed between two linacs, separate-type drift tube linac (SDTL) and an annular-ring-coupled structure linac (ACS), having acceleration frequencies of 324 and 972 MHz, respectively. We used radio-frequency amplitude modulation of bunches in the beam transport between the SDTL and ACS to minimize emittance growth and beam loss. We conducted amplitude scanning and compared the results with the twiss-parameters obtained from the transverse profiles. In this paper, we discuss the results of amplitude tuning of the buncher cavity at the point of beam loss and emittance. We also discuss the measurement results for various equipartitioning settings of quadrupole magnets.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG43

Export •

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

TUPG12

Design for the Diamond Longitudinal Bunch-by-Bunch Feedback Cavity

cavity, impedance, HOM, coupling

340

A.F.D. Morgan, G. Rehm
DLS, Oxfordshire, United Kingdom

In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. In order to deal with the potential higher order modes in these we are designing a longitudinal bunch-by-bunch feedback system. This paper will focus on the design of the overloaded cavity kicker, adapted to the Diamond beam pipe cross section. The design has evolved in order to reduce the strong 3rd harmonic resonance seen on the introduction of the racetrack beam pipe. Through a combination of geometry optimisation and the addition of integrated taper transitions this harmonic has been greatly reduced while also minimising sharp resonances below 15GHz. The major features will be described, as well as the expected performance parameters.

Poster TUPG12 [1.423 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG12

Export •

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

TUPG18

Design Optimization of Button-Type BPM Electrode for the SPring-8 Upgrade

impedance, simulation, storage-ring, vacuum

360

M. Masaki, H. Dewa, T. Fujita, S. Takano
JASRI, Hyogo, Japan
H. Maesaka, S. Takano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

The requirements for a BPM system for the SPring-8 upgrade are long-term stability, sufficient signal intensity and high accuracy*. The design of a button-type electrode for the BPM has been optimized from the perspectives of 1) mechanical structure, 2) rf characteristics, 3) thermal issue. We have adopted the electrode structure without a sleeve enclosing the button to maximize the button diameter for the narrow aperture of the vacuum chamber. The absence of an annular slot around the sleeve in a lodging hole for the electrode eliminates the associated beam impedance. To minimize the beam impedance and the trapped mode heating of the electrode, the rf structure has been optimized by 3D electro-magnetic simulations. To suppress the ohmic loss on the button and center pin thermally isolated from the water cooled BPM block, we have selected molybdenum as a material with high electric and thermal conductivities. The reduction of the heating suppresses thermal deformation of the electrode and the BPM block, and improves thermal stability of the BPM system. The mechanical tolerance of the electrode was defined to fit the error budget for the total BPM offset error of 0.1 mm rms.
* H. Maesaka et al., in this conference.

Poster TUPG18 [1.104 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUPG18

Export •

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

WECL03

Measurement of the Beam Response to Quadrupole Kick by Using Stripline Pickup Monitor at J-PARC Main Ring

kicker, quadrupole, betatron, operation

604

Y. Nakanishi, A. Ichikawa, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya
Kyoto University, Kyoto, Japan
T. Koseki, H. Kuboki, M. Okada, T. Toyama
KEK, Tokai, Ibaraki, Japan

Funding: Work supported by MEXT KAKENHI, GA 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled "Unification and Development of the Neutrino Science Frontier"
In high intensity proton synchrotrons, linear and nonlinear betatron resonances cause beam loss. When the betatron tune spreads over a resonance line, the oscillation amplitude will get larger, causing a large beam loss. Our study aims for a direct measurement of the betatron tune spread by using a quadrupole kicker and a 4-electrode monitor. The monochromatic rf signal is inputted to the kicker and we induce an oscillation by kicking the beam. The amplitude of the quadrupole oscillation will depend on the number of particles having a certain tune. In the beam test at J-PARC MR, the dipole kicker was used as a quadrupole kicker by exciting the two facing electrodes in-phase. We measured the response to the kick at several frequencies. We observed that the amplitude depends on the kicker frequency and the number of particles per bunch. This demonstrates that the quadrupole oscillation can be induced by a kicker and the possibility of measuring the number of a particular tune particle from the response. We will present the result of the beam test and our prospect and the comparison between the experimental result and a numerical calculation.

Slides WECL03 [2.054 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WECL03

Export •

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

WEPG32

First Heating with the European XFEL Laser Heater

laser, electron, undulator, interaction-region

694

M. Hamberg
Uppsala University, Uppsala, Sweden
F. Brinker, M. Scholz
DESY, Hamburg, Germany

Funding: DESY and Swedish Research council
The European XFEL is a 3.4 km long free-electron laser (FEL) which will deliver radiation in the wavelength regime of 0.05 to 4.7 nm. To avoid problems with longitudinal microbunching instabilities a laser heater is implemented. It heats up the electron bunches which will improve the overall brightness level of the FEL. I report the commissioning steps undertaken and the first recorded heating outputs observed in the injector section.

Poster WEPG32 [2.322 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG32

Export •

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

WEPG41

Measurement of Coupling Impedances using a Goubau Line

impedance, simulation, coupling, scattering

719

F. Stulle, J.F. Bergoz
BERGOZ Instrumentation, Saint Genis Pouilly, France
H.-W. Glock
HZB, Berlin, Germany

Longitudinal coupling impedances can be deduced from S-Parameter measurements performed on a Goubau Line. The Goubau Line, also known as single wire line, is a variant of the coaxial wire method. Both setups use a wire for mimicking the particle beam. Coaxial tapers at the wire ends adapt wave impedance to the 50ohm impedance of coaxial cables, sources and receivers. But for guiding the electromagnetic wave, the Goubau Line relies on the realistic boundary conditions imposed by an insulated wire instead of using a coaxial shield. Equations for the deduction of longitudinal coupling impedances are reviewed and applied to Goubau Line measurements. Goubau Line measurements and CST Studio simulations are compared, showing good agreement.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEPG41

Export •

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