IBIC2012 - List of Keywords (wakefield)

Paper	Title	Other Keywords	Page
MOPA38	Development of the System for Longitudinal Coupled Bunch Modes Measurement at Indus-2	synchrotron, software, damping, interface	146
	S. Yadav, A.C. Holikatti, C.P. Navathe, A. Ojha, T.A. Puntambekar, Y. Tyagi RRCAT, Indore (M.P.), India
	In a circular accelerator, beam instabilities are intensity-dependent collective effects that arise because of the electromagnetic wake fields generated by the beam as it interacts with its environment. These instabilities limit the high current operation in the accelerator and degrade the performance of synchrotron radiation beam. Indus-2 is a synchrotron radiation source at RRCAT, Indore having design beam current of 300 mA and 2.5 GeV beam energy. Beam intensity signal obtained from wall current monitor (WCM) is used to measure the longitudinal coupled bunch modes (CBM). To study the beam instabilities, an automated software has been developed which acquires the beam intensity spectrum for measurement of coupled bunch modes. The software has option of complete CBM scan, scanning near the significant RF cavity higher order modes (HOM) and scanning of user-selected modes. The scanning time for complete 291 modes is ~5 minutes. In this paper, we describe the measurement system, features of the developed software and some measurement results on Indus-2 machine.

TUPB70	The ATF2 Multi-OTR System: Studies and Design Improvements	emittance, target, coupling, operation	505
	J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós, J. Resta-López IFIC, Valencia, Spain J. Cruz, D.J. McCormick, G.R. White, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515. A multi-Optical Transition Radiation system made of four stations has been installed in the extraction line of ATF2 and has been fully operational since September 2011. The system is being used routinely for beam size and emittance measurements as well as for coupling correction and energy spread measurements. In this paper we present the beam sizes and emittance measurements performed during 2012 runs as well as a detailed study of the experimental single-shot automated coupling correction and the comparison with the simulations. Wakefields problems experimented with the simultaneous measurement has been studied and will be solved by new target holders that will be installed in the next Fall 2012 run.

TUPB85	Spectrum of Multi-bunch Position Model and Parameter Acquisition Algorithm	storage-ring, injection, electron, experiment	540
	Y. Yang, Y.B. Leng SSRF, Shanghai, People's Republic of China B.P. Wang SINAP, Shanghai, People's Republic of China
	Based on the spectrum of turn-by-turn model for the storage ring, spectrum of multi-bunch position model was derived through some assumptions. Spectrum of excited electron beam position was analyzed in Shanghai Synchrotron Radiation Facility(SSRF) and Genetic Algorithm was used to obtain the model parameters when fitting multi-curve data. Results show that, after 100 times iteration, all the correlation of fitted data and original data can be up to 95%, and the model can accurate estimate a bimodal split of the spectrum curve.

Paper

Title

Other Keywords

Page

MOPA38

Development of the System for Longitudinal Coupled Bunch Modes Measurement at Indus-2

synchrotron, software, damping, interface

146

S. Yadav, A.C. Holikatti, C.P. Navathe, A. Ojha, T.A. Puntambekar, Y. Tyagi
RRCAT, Indore (M.P.), India

In a circular accelerator, beam instabilities are intensity-dependent collective effects that arise because of the electromagnetic wake fields generated by the beam as it interacts with its environment. These instabilities limit the high current operation in the accelerator and degrade the performance of synchrotron radiation beam. Indus-2 is a synchrotron radiation source at RRCAT, Indore having design beam current of 300 mA and 2.5 GeV beam energy. Beam intensity signal obtained from wall current monitor (WCM) is used to measure the longitudinal coupled bunch modes (CBM). To study the beam instabilities, an automated software has been developed which acquires the beam intensity spectrum for measurement of coupled bunch modes. The software has option of complete CBM scan, scanning near the significant RF cavity higher order modes (HOM) and scanning of user-selected modes. The scanning time for complete 291 modes is ~5 minutes. In this paper, we describe the measurement system, features of the developed software and some measurement results on Indus-2 machine.

TUPB70

The ATF2 Multi-OTR System: Studies and Design Improvements

emittance, target, coupling, operation

505

J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós, J. Resta-López
IFIC, Valencia, Spain
J. Cruz, D.J. McCormick, G.R. White, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515.
A multi-Optical Transition Radiation system made of four stations has been installed in the extraction line of ATF2 and has been fully operational since September 2011. The system is being used routinely for beam size and emittance measurements as well as for coupling correction and energy spread measurements. In this paper we present the beam sizes and emittance measurements performed during 2012 runs as well as a detailed study of the experimental single-shot automated coupling correction and the comparison with the simulations. Wakefields problems experimented with the simultaneous measurement has been studied and will be solved by new target holders that will be installed in the next Fall 2012 run.

TUPB85

Spectrum of Multi-bunch Position Model and Parameter Acquisition Algorithm

storage-ring, injection, electron, experiment

540

Y. Yang, Y.B. Leng
SSRF, Shanghai, People's Republic of China
B.P. Wang
SINAP, Shanghai, People's Republic of China

Based on the spectrum of turn-by-turn model for the storage ring, spectrum of multi-bunch position model was derived through some assumptions. Spectrum of excited electron beam position was analyzed in Shanghai Synchrotron Radiation Facility(SSRF) and Genetic Algorithm was used to obtain the model parameters when fitting multi-curve data. Results show that, after 100 times iteration, all the correlation of fitted data and original data can be up to 95%, and the model can accurate estimate a bimodal split of the spectrum curve.