IPAC2017 - List of Authors (Okugi, T.)

Paper	Title	Page
TUPIK097	Improving the Performance of an Orbit Feed-forward Based on Quadrupole Motion at the KEK ATF	1931
	D.R. Bett, C. Charrondière, M. Patecki, J. Pfingstner, D. Schulte, R. Tomás CERN, Geneva, Switzerland P. Burrows, G.B. Christian, C. Perry JAI, Oxford, United Kingdom A. Jeremie IN2P3-LAPP, Annecy-le-Vieux, France K. Kubo, S. Kuroda, T. Naito, T. Okugi, T.T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	The high luminosity requirement for a future linear collider sets a demanding limit on the beam quality at the Interation Point (IP). Even the natural motion of the ground could misalign the quadrupole magnets to such an extent that the resulting dipole kicks would require compensation. The novel technique described in this paper uses seismometers to measure the positions of the quadrupole magnets in real time and a kicker to counteract the effect of their misalignment. The prototype system deployed at the Accelerator Test Facility (ATF) at KEK in Japan has already demonstrated a reduction in the pulse-to-pulse vertical position jitter of the beam by about 10%. Based on the observed correlation of the beam position to the quadrupole positions the maximum possible jitter reduction from such a system is estimated to be about 25%. This paper details the latest improvements made to the system with the aim of achieving this limit.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK097
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THPVA002	Numerical Investigation of Beam Halo From Beam Gas Scattering in KEK-ATF	4410
	R.J. Yang, P. Bambade LAL, Orsay, France K. Kubo, T. Okugi, N. Terunuma, D. Zhou KEK, Ibaraki, Japan
	To demonstrate the final focus schemes of the Future Linear Collider (FLC), the Accelerator Test Facility 2 (ATF2) at KEK is devoted to focus the beam to a RMS size of a few tens of nanometers (nm) vertically and to provide stability at the nm level at the virtual Interaction Point (IP). However, the loss of halo particles upstream will introduce background to the diagnostic instrument measuring the ultra-small beam, using a laser interferometer monitor. To help the realization of the above goals and beam operation, understanding and mitigation of beam halo are crucial. In this paper, we present the systematical simulation of beam halo formation from beam gas Coulomb scattering (BGS) in the ATF damping ring. The behavior of beam halo with various machine parameters is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA002
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TUPIK075	ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs	1864
	N. Fuster-Martínez, A. Faus-Golfe IFIC, Valencia, Spain P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang LAL, Orsay, France K. Kubo, T. Okugi, T. Tauchi, N. Terunuma Sokendai, Ibaraki, Japan S. Kuroda KEK, Ibaraki, Japan I. Podadera, F. Toral CIEMAT, Madrid, Spain G.R. White SLAC, Menlo Park, California, USA
	A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK075
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Paper

Title

Page

Improving the Performance of an Orbit Feed-forward Based on Quadrupole Motion at the KEK ATF

1931

D.R. Bett, C. Charrondière, M. Patecki, J. Pfingstner, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
P. Burrows, G.B. Christian, C. Perry
JAI, Oxford, United Kingdom
A. Jeremie
IN2P3-LAPP, Annecy-le-Vieux, France
K. Kubo, S. Kuroda, T. Naito, T. Okugi, T.T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

The high luminosity requirement for a future linear collider sets a demanding limit on the beam quality at the Interation Point (IP). Even the natural motion of the ground could misalign the quadrupole magnets to such an extent that the resulting dipole kicks would require compensation. The novel technique described in this paper uses seismometers to measure the positions of the quadrupole magnets in real time and a kicker to counteract the effect of their misalignment. The prototype system deployed at the Accelerator Test Facility (ATF) at KEK in Japan has already demonstrated a reduction in the pulse-to-pulse vertical position jitter of the beam by about 10%. Based on the observed correlation of the beam position to the quadrupole positions the maximum possible jitter reduction from such a system is estimated to be about 25%. This paper details the latest improvements made to the system with the aim of achieving this limit.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK097

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

THPVA002

Numerical Investigation of Beam Halo From Beam Gas Scattering in KEK-ATF

4410

R.J. Yang, P. Bambade
LAL, Orsay, France
K. Kubo, T. Okugi, N. Terunuma, D. Zhou
KEK, Ibaraki, Japan

To demonstrate the final focus schemes of the Future Linear Collider (FLC), the Accelerator Test Facility 2 (ATF2) at KEK is devoted to focus the beam to a RMS size of a few tens of nanometers (nm) vertically and to provide stability at the nm level at the virtual Interaction Point (IP). However, the loss of halo particles upstream will introduce background to the diagnostic instrument measuring the ultra-small beam, using a laser interferometer monitor. To help the realization of the above goals and beam operation, understanding and mitigation of beam halo are crucial. In this paper, we present the systematical simulation of beam halo formation from beam gas Coulomb scattering (BGS) in the ATF damping ring. The behavior of beam halo with various machine parameters is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA002

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

TUPIK075

ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs

1864

N. Fuster-Martínez, A. Faus-Golfe
IFIC, Valencia, Spain
P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang
LAL, Orsay, France
K. Kubo, T. Okugi, T. Tauchi, N. Terunuma
Sokendai, Ibaraki, Japan
S. Kuroda
KEK, Ibaraki, Japan
I. Podadera, F. Toral
CIEMAT, Madrid, Spain
G.R. White
SLAC, Menlo Park, California, USA

A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK075

Export •

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