HB2018 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOP2WA04	Recent Results from the Wideband Feedback System Tests at the SPS and Future Plans	feedback, optics, kicker, controls	38
	K.S.B. Li, H. Bartosik, M.S. Beck, E.R. Bjørsvik, W. Höfle, G. Kotzian, T.E. Levens, M. Schenk CERN, Geneva, Switzerland J.E. Dusatko, J.D. Fox, C.H. Rivetta SLAC, Menlo Park, California, USA M. Schenk EPFL, Lausanne, Switzerland O. Turgut Stanford University, Stanford, California, USA
	A high bandwidth transverse feedback demonstrator system has been devised within the LARP framework in collaboration with SLAC for the LHC Injectors Upgrade (LIU) Project. The initial system targeted the Super Proton Synchrotron (SPS) at CERN to combat TMCI and electron cloud instabilities induced for bunches with bunch lengths at the 100 MHz scale. It features a very fast digital signal processing system running at up to 4~GS/s and high bandwidth kickers with a frequency reach of ultimately beyond 1~GHz. In recent years, the system has gradually been extended and now includes two stripline kickers for a total power of 1~kW delivering correction signals at frequencies of currently more than 700~MHz. This talk will cover recent studies using this demonstrator system to overcome TMCI limitations in the SPS. We will conclude with future plans and also briefly mention potential applications and requirements for larger machines such as the LHC or the HL-LHC.
	Slides MOP2WA04 [19.091 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP2WA04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP2WA05	Simulation and Measurement of the TMCI Threshold in the LHC	impedance, simulation, operation, synchrotron	43
	D. Amorim, S. A. Antipov, N. Biancacci, X. Buffat, L.R. Carver, E. Métral CERN, Geneva, Switzerland
	The transverse mode coupling instability occurs in individual bunches when two transverse oscillation modes couple at high intensity. Simulations predict an instability threshold in the LHC at a single bunch intensity of 3*10¹¹ protons. The TMCI threshold can be inferred by measuring the tune shift as a function of intensity. This measurement was performed in the LHC for different machine impedances and bunch intensities. The impedance was changed by varying the primary and secondary collimators gaps to increase their contribution to the resistive wall impedance. The experiment also allowed to assess the validity of the LHC impedance model in the single bunch case.
	Slides MOP2WA05 [4.729 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP2WA05
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP2PO024	Resonance Stop-bands Compensation at Booster Ring of HIAF	resonance, alignment, injection, betatron	315
	J. Li, J.C. Yang IMP/CAS, Lanzhou, People's Republic of China
	Booster Ring (BRing) of the new approved High Intensity heavy-ion Accelerator Facility (HIAF) in China is designed to stack 0.3-1.0·10¹¹ number of 238U³⁵⁺ ions by painting injection and deliver over such intensity beam in extraction. However, depressed tune spread caused by space charge effect crosses the low-order resonance stop-bands after bunching the storage beam. To keep a low beam loss during crossing, stop-band compensation scheme is proposed covering the whole process of RF capture and early acceleration.
	Poster WEP2PO024 [1.218 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO024
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOP2WA04

Recent Results from the Wideband Feedback System Tests at the SPS and Future Plans

feedback, optics, kicker, controls

38

K.S.B. Li, H. Bartosik, M.S. Beck, E.R. Bjørsvik, W. Höfle, G. Kotzian, T.E. Levens, M. Schenk
CERN, Geneva, Switzerland
J.E. Dusatko, J.D. Fox, C.H. Rivetta
SLAC, Menlo Park, California, USA
M. Schenk
EPFL, Lausanne, Switzerland
O. Turgut
Stanford University, Stanford, California, USA

A high bandwidth transverse feedback demonstrator system has been devised within the LARP framework in collaboration with SLAC for the LHC Injectors Upgrade (LIU) Project. The initial system targeted the Super Proton Synchrotron (SPS) at CERN to combat TMCI and electron cloud instabilities induced for bunches with bunch lengths at the 100 MHz scale. It features a very fast digital signal processing system running at up to 4~GS/s and high bandwidth kickers with a frequency reach of ultimately beyond 1~GHz. In recent years, the system has gradually been extended and now includes two stripline kickers for a total power of 1~kW delivering correction signals at frequencies of currently more than 700~MHz. This talk will cover recent studies using this demonstrator system to overcome TMCI limitations in the SPS. We will conclude with future plans and also briefly mention potential applications and requirements for larger machines such as the LHC or the HL-LHC.

Slides MOP2WA04 [19.091 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP2WA04

Export •

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

MOP2WA05

Simulation and Measurement of the TMCI Threshold in the LHC

impedance, simulation, operation, synchrotron

43

D. Amorim, S. A. Antipov, N. Biancacci, X. Buffat, L.R. Carver, E. Métral
CERN, Geneva, Switzerland

The transverse mode coupling instability occurs in individual bunches when two transverse oscillation modes couple at high intensity. Simulations predict an instability threshold in the LHC at a single bunch intensity of 3*10¹¹ protons. The TMCI threshold can be inferred by measuring the tune shift as a function of intensity. This measurement was performed in the LHC for different machine impedances and bunch intensities. The impedance was changed by varying the primary and secondary collimators gaps to increase their contribution to the resistive wall impedance. The experiment also allowed to assess the validity of the LHC impedance model in the single bunch case.

Slides MOP2WA05 [4.729 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-MOP2WA05

Export •

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

WEP2PO024

Resonance Stop-bands Compensation at Booster Ring of HIAF

resonance, alignment, injection, betatron

315

J. Li, J.C. Yang
IMP/CAS, Lanzhou, People's Republic of China

Booster Ring (BRing) of the new approved High Intensity heavy-ion Accelerator Facility (HIAF) in China is designed to stack 0.3-1.0·10¹¹ number of 238U³⁵⁺ ions by painting injection and deliver over such intensity beam in extraction. However, depressed tune spread caused by space charge effect crosses the low-order resonance stop-bands after bunching the storage beam. To keep a low beam loss during crossing, stop-band compensation scheme is proposed covering the whole process of RF capture and early acceleration.

Poster WEP2PO024 [1.218 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO024

Export •

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