| Paper |
Title |
Page |
| TUOAB04 |
Optics Corrections including IP Local Coupling at SuperKEKB |
63 |
| |
- A. Morita, H. Koiso, K. Ohmi, Y. Ohnishi, H. Sugimoto, D. Zhou
KEK, Ibaraki, Japan
|
|
| |
The phase-2 commissioning of the SuperKEKB accelerator with the interaction point(IP) has been performed from March 19 to July 17. In the collision operation during this commissioning, the vertical beta function at the IP was squeezed down to 3mm. In order to achieve such low beta collision operation, many optics corrections were performed. We present the result of those optics measurement and correction.
|
|
| DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-eeFACT2018-TUOAB04
|
|
| About • |
paper received ※ 12 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019 |
|
| Export • |
reference for this paper using
※ BibTeX,
※ LaTeX,
※ Text/Word,
※ RIS,
※ EndNote (xml)
|
|
| |
| TUOBB01 |
Optics Aberration at IP and Beam-beam Effects |
66 |
| |
- K. Ohmi, Y. Funakoshi, H. Koiso, A. Morita, Y. Ohnishi, D. Zhou
KEK, Ibaraki, Japan
- K. Hirosawa
Sokendai, Ibaraki, Japan
|
|
| |
Collision in SuperKEKB phase II commissioning has started in April 2018. Luminosity was lower than the geomterical value even in very low bunch current. Linear x-y coupling at IP caused by skew of QCS was conjectured as error source. x-y coupling correction using skew corrector of QCS resulted in luminosity recover of 2 times. After the QCS skew correction, luminosity is still limited at relatively low bunch current. Nonlinear x-y coupling at IP is conjectured as a source of the luminosity limitation. We discuss effects of linear and nonlinear x-y coupling at IP on the beam-beam performance.
|
|
| DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-eeFACT2018-TUOBB01
|
|
| About • |
paper received ※ 25 September 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019 |
|
| Export • |
reference for this paper using
※ BibTeX,
※ LaTeX,
※ Text/Word,
※ RIS,
※ EndNote (xml)
|
|
| |
| TUOBB02 |
Off-momentum Optics at SuperKEKB |
71 |
| |
- Y. Ohnishi, H. Koiso, A. Morita, K. Ohmi, H. Sugimoto
KEK, Ibaraki, Japan
- K. Oide
CERN, Meyrin, Switzerland
|
|
| |
The nano-beam scheme can squeeze the vertical beta function at the IP much smaller than the bunch length. It implies that the large chromaticity is generated in the vicinity of the final focus quadrupole magnets and the strong sextupoles are adopted to correct the chromaticity, for instance the local chromaticity corrections. While understanding of the off-momentum optics is important to optimize the dynamic aperture to make Touschek lifetime long and to reduce the luminosity degradation due to chromatic behaviors. In general, there is a discrepancy between measurements and those obtained from the optics model. The chromatic phase-advance is introduced to measure the off-momentum optics and correct by using sextupole magnets.
|
|
| DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-eeFACT2018-TUOBB02
|
|
| About • |
paper received ※ 12 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019 |
|
| Export • |
reference for this paper using
※ BibTeX,
※ LaTeX,
※ Text/Word,
※ RIS,
※ EndNote (xml)
|
|
| |