eeFACT2018 - List of Authors (Koop, I.)

Paper	Title	Page
MOYBA01	Round Colliding Beams at Vepp-2000 with Extreme Tuneshifts	34
	D.B. Shwartz, V.V. Anashin, O.V. Belikov, D.E. Berkaev, K. Gorchakov, A.S. Kasaev, A.N. Kirpotin, I. Koop, A.A. Krasnov, G.Y. Kurkin, A.P. Lysenko, S.V. Motygin, E. Perevedentsev, V.P. Prosvetov, D.V. Rabusov, Yu. A. Rogovsky, A.M. Semenov, A.I. Senchenko, D.N. Shatilov, P.Yu. Shatunov, Y.M. Shatunov, O.S. Shubina, M.V. Timoshenko, I.M. Zemlyansky, Yu.M. Zharinov BINP SB RAS, Novosibirsk, Russia I. Koop, E. Perevedentsev, Yu. A. Rogovsky, A.I. Senchenko, Y.M. Shatunov, D.B. Shwartz NSU, Novosibirsk, Russia
	VEPP-2000 is the only electron-positron collider operating with round beams that allow to enhance beam-beam limit. VEPP-2000 with SND and CMD-3 detectors carried out two successful data-taking runs after new BINP injection complex was commissioned. The 2016/2017 run was dedicated to high energy range (640-1000 MeV per beam) while the 2017/2018 run was focused at 275-600 MeV/beam energies. With sufficient positron production rate and upgraded full-energy booster the collider luminosity was limited by beam-beam effects, namely flip-flop effect. Thorough machine tuning together with new ideas introduced to suppress flip-flop allowed to achieve high beam-beam tuneshift and bunch-by-bunch luminosity values at specific beam energies. The achieved luminosity increased 2-5 times in a whole energy range in comparison to phase-1 operation (2010-2013).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-MOYBA01
About •	paper received ※ 11 October 2018 paper accepted ※ 19 February 2019 issue date ※ 21 April 2019
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TUPBB04	Resonant Depolarization at Z and W at FCC-ee	165
	I. Koop BINP SB RAS, Novosibirsk, Russia
	Both future 100 km in circumference electron-positron colliders CEPC and FCC-ee need know beams energies with the extreme precision of 1-2 ppm. This can be done only with the help of Resonant Depolarization (RD) technique. Still, some beam parameters of these machines, like energy spread and damping decrements, are so high near 80 GeV per beam, that it is required special consideration and tricks to overcome the difficulties. The author has written simple spin tracking code, which simulates main features of the RD process in presence of continuous energy diffusion due to synchrotron radiation fluctuations. It was shown by this study, that the applicability of the RD method is limited by the effect of widening of a width of the central peak of the spin precession spectrum when the synchrotron tune is chosen too low, say below 0.05. In this case spin precession lost its resonant nature due to overlap of the wide central spectrum peak with nearby synchrotron side bands. Dependencies of the spectrum peaks width from various beam parameters and a new RD-procedure recipe are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPBB04
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)

WEXAA04	Ideas for Longitudinal Polarization at the Z/W/H/top Factory	190
	I. Koop, A.V. Otboev BINP SB RAS, Novosibirsk, Russia Yu.M. Shatunov Budker INP & NSU, Novosibirsk, Russia
	Different schemes for getting the longitudinal polarization at FCC-ee are considered. Depolarization rates for rings with spin rotators are evaluated and methods of acceleration of polarized beams in a booster synchrotron are proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-WEXAA04
About •	paper received ※ 10 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)

Paper

Title

Page

Round Colliding Beams at Vepp-2000 with Extreme Tuneshifts

34

D.B. Shwartz, V.V. Anashin, O.V. Belikov, D.E. Berkaev, K. Gorchakov, A.S. Kasaev, A.N. Kirpotin, I. Koop, A.A. Krasnov, G.Y. Kurkin, A.P. Lysenko, S.V. Motygin, E. Perevedentsev, V.P. Prosvetov, D.V. Rabusov, Yu. A. Rogovsky, A.M. Semenov, A.I. Senchenko, D.N. Shatilov, P.Yu. Shatunov, Y.M. Shatunov, O.S. Shubina, M.V. Timoshenko, I.M. Zemlyansky, Yu.M. Zharinov
BINP SB RAS, Novosibirsk, Russia
I. Koop, E. Perevedentsev, Yu. A. Rogovsky, A.I. Senchenko, Y.M. Shatunov, D.B. Shwartz
NSU, Novosibirsk, Russia

VEPP-2000 is the only electron-positron collider operating with round beams that allow to enhance beam-beam limit. VEPP-2000 with SND and CMD-3 detectors carried out two successful data-taking runs after new BINP injection complex was commissioned. The 2016/2017 run was dedicated to high energy range (640-1000 MeV per beam) while the 2017/2018 run was focused at 275-600 MeV/beam energies. With sufficient positron production rate and upgraded full-energy booster the collider luminosity was limited by beam-beam effects, namely flip-flop effect. Thorough machine tuning together with new ideas introduced to suppress flip-flop allowed to achieve high beam-beam tuneshift and bunch-by-bunch luminosity values at specific beam energies. The achieved luminosity increased 2-5 times in a whole energy range in comparison to phase-1 operation (2010-2013).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-MOYBA01

About •

paper received ※ 11 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)

TUPBB04

Resonant Depolarization at Z and W at FCC-ee

165

I. Koop
BINP SB RAS, Novosibirsk, Russia

Both future 100 km in circumference electron-positron colliders CEPC and FCC-ee need know beams energies with the extreme precision of 1-2 ppm. This can be done only with the help of Resonant Depolarization (RD) technique. Still, some beam parameters of these machines, like energy spread and damping decrements, are so high near 80 GeV per beam, that it is required special consideration and tricks to overcome the difficulties. The author has written simple spin tracking code, which simulates main features of the RD process in presence of continuous energy diffusion due to synchrotron radiation fluctuations. It was shown by this study, that the applicability of the RD method is limited by the effect of widening of a width of the central peak of the spin precession spectrum when the synchrotron tune is chosen too low, say below 0.05. In this case spin precession lost its resonant nature due to overlap of the wide central spectrum peak with nearby synchrotron side bands. Dependencies of the spectrum peaks width from various beam parameters and a new RD-procedure recipe are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-TUPBB04

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)

WEXAA04

Ideas for Longitudinal Polarization at the Z/W/H/top Factory

190

I. Koop, A.V. Otboev
BINP SB RAS, Novosibirsk, Russia
Yu.M. Shatunov
Budker INP & NSU, Novosibirsk, Russia

Different schemes for getting the longitudinal polarization at FCC-ee are considered. Depolarization rates for rings with spin rotators are evaluated and methods of acceleration of polarized beams in a booster synchrotron are proposed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-eeFACT2018-WEXAA04

About •

paper received ※ 10 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)