IPAC2013 - List of Authors (Oide, K.)

Paper	Title	Page
TUPME014	Coherent Synchrotron Radiation Predicted at the SuperKEKB Damping Ring	1595
	H. Ikeda, M. Kikuchi, K. Ohmi, K. Oide, D. Zhou KEK, Ibaraki, Japan
	The damping ring of SuperKEKB is under construction in order to inject low emittance positron beam into the main ring. We calculated the bunch lengthening and the energy spread caused by the longitudinal wake, which is dominated by the CSR wake field. The result was within the tolerance level.

TUPME016	Crosstalk Between Beam-beam Interaction and Lattice Nonlinearities in the SuperKEKB	1601
	D. Zhou, K. Ohmi, Y. Ohnishi, K. Oide, H. Sugimoto KEK, Ibaraki, Japan
	Momentum-dependent lattice nonlinearities have been proven to be important for the luminosity performance in the KEKB B-factory. As an upgrade of KEKB, the SuperKEKB adopts nano-beam scheme, in which the colliding beams are squeezed to extremely small sizes at the interaction point. Consequently, the lattice nonlinearities in SuperKEKB become more stronger than in KEKB. Using two codes, SAD and BBWS, we did various simulations to study the crosstalk between beam-beam interaction and lattice nonlinearities. It is found that lattice nonlinearities can cause remarkable luminosity loss in the SuperKEKB.

TUPME017	Validation of the Microwave Instability in the Damping Ring of SuperKEKB using VFP Solver	1604
	L. Wang SLAC, Menlo Park, California, USA H. Ikeda, K. Ohmi, K. Oide, D. Zhou KEK, Ibaraki, Japan
	Microwave instability driven by CSR impedance in the damping ring of Super-KEKB is a concern due to its high bunch current. To understand the beam dynamics, we simulate the microwave instability using Vlasov-Fokker-Planck (VFP) solver. The longitudinal wake potential is calculated as a sum of the contributions due to vacuum chamber components distributed around the ring, including geometry wake field and CSR wake. To improve the accuracy of the simulation of microwave instability, the coherent synchrotron radiation impedance is calculated to very high frequency to get more accurate wake field with a short bunch. The CSR wake is much larger than the geometry wake. The threshold is just above the design current and saw-tooth type of instability is found above the threshold.

Paper

Title

Page

Coherent Synchrotron Radiation Predicted at the SuperKEKB Damping Ring

1595

H. Ikeda, M. Kikuchi, K. Ohmi, K. Oide, D. Zhou
KEK, Ibaraki, Japan

The damping ring of SuperKEKB is under construction in order to inject low emittance positron beam into the main ring. We calculated the bunch lengthening and the energy spread caused by the longitudinal wake, which is dominated by the CSR wake field. The result was within the tolerance level.

TUPME016

Crosstalk Between Beam-beam Interaction and Lattice Nonlinearities in the SuperKEKB

1601

D. Zhou, K. Ohmi, Y. Ohnishi, K. Oide, H. Sugimoto
KEK, Ibaraki, Japan

Momentum-dependent lattice nonlinearities have been proven to be important for the luminosity performance in the KEKB B-factory. As an upgrade of KEKB, the SuperKEKB adopts nano-beam scheme, in which the colliding beams are squeezed to extremely small sizes at the interaction point. Consequently, the lattice nonlinearities in SuperKEKB become more stronger than in KEKB. Using two codes, SAD and BBWS, we did various simulations to study the crosstalk between beam-beam interaction and lattice nonlinearities. It is found that lattice nonlinearities can cause remarkable luminosity loss in the SuperKEKB.

TUPME017

Validation of the Microwave Instability in the Damping Ring of SuperKEKB using VFP Solver

1604

L. Wang
SLAC, Menlo Park, California, USA
H. Ikeda, K. Ohmi, K. Oide, D. Zhou
KEK, Ibaraki, Japan

Microwave instability driven by CSR impedance in the damping ring of Super-KEKB is a concern due to its high bunch current. To understand the beam dynamics, we simulate the microwave instability using Vlasov-Fokker-Planck (VFP) solver. The longitudinal wake potential is calculated as a sum of the contributions due to vacuum chamber components distributed around the ring, including geometry wake field and CSR wake. To improve the accuracy of the simulation of microwave instability, the coherent synchrotron radiation impedance is calculated to very high frequency to get more accurate wake field with a short bunch. The CSR wake is much larger than the geometry wake. The threshold is just above the design current and saw-tooth type of instability is found above the threshold.