IPAC2011 - List of Authors (Kim, E.-S.)

Paper	Title	Page
TUPC097	Status of Cold Cavity Beam Position Monitor for STF	1236
	E.-S. Kim, A. Heo KNU, Deagu, Republic of Korea H. Hayano KEK, Ibaraki, Japan
	Cold cavity BPM was developed to meet high position resolution and bunch to bunch measurement time. It is designed based on re-entrant cavity and has Low-Q to achieve short signal decay time in L-band frequency with large aperture as 78mm. The beam test was performed to demonstrate position resolution at ATF main linac, which is operating with 1.6nC bunch charge, while BPM will be installed inside the ILC cyomodule with 3.2nC spacing 369ns like as ILC at STF. Stripline BPMs, ML2P and ML3P installed upstream and downstream of the BPM’s location respectively were used to predict its position. Reference cavity was optimized to use for synchronous detection. We had achieved ~340nm position resolution since position resolution was estimated due to limitation of system with noise, namely in case of ideal state. We will present configuration of beam test, procedure to measure position resolution and the result on the test. Furthermore, new design will be introduced to improve signal intensity and have heavy coupling.

TUPC161	Cavity Beam Position Monitor System for ATF2	1410
	S.T. Boogert, R. Ainsworth, G.E. Boorman, S. Molloy Royal Holloway, University of London, Surrey, United Kingdom A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan F.J. Cullinan, N.Y. Joshi, A. Lyapin JAI, Egham, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White SLAC, Menlo Park, California, USA A. Heo, E.-S. Kim, Y.I. Kim KNU, Deagu, Republic of Korea
	The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high resolution C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitizers. In addition 4 high resolution BPMs have been recently installed at the interaction point, we briefly describe the first operational experience of these cavities in the ATF2 beam-line. The current status of the overall BPM system is also described, with a focus on operational techniques and performance.

TUPO033	Emittance Minimization by Courant-Snyder Parameter Scan in Merger Section at the Compact Energy Recovery Linear Accelerator.	1506
	J.G. Hwang Kyungpook National University, Daegu, Republic of Korea E.-S. Kim KNU, Deagu, Republic of Korea T. Miyajima KEK, Tsukuba, Japan
	The project of compact-Energy Recovery Linac(c-ERL) at Photon Factory in KEK is a test facility for the 5 GeV ERL, which is one of the candidates of next generation light source. It consists of injector system, merger section, main SRF section, return arc, long straight section and beam dump. The injector system produces beams with a low-energy of 5 MeV and low-emittance less than 1 mm-mrad. It causes the large emittance growth by space charge force in merger section, which consists of two rectangular type dipole magnets and one sector type magnet. Dispersion also causes the displacement of bunch sllice on horizontal plane. The displacement of bunch slice is laid on the kick angle induced by space charge force. Also, each slice has the orientation of the phase ellipse on horizontal phase space. Therefore, the emittance growth due to the displacement of bunch sllice induced by space charge force in the horizontal phase space can be minimized by matching the displacement to the orientation of the phase ellipse at the exit of merger. We present the results of the emittance minimization performed by mathcing of the angle of the phase ellipse by scan of CS (Courant-Snyder) parameter.

TUPC118	Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2	1293
	S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim Kyungpook National University, Daegu, Republic of Korea H.K. Park CHEP, Daegu, Republic of Korea
	We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.

Paper

Title

Page

Status of Cold Cavity Beam Position Monitor for STF

1236

E.-S. Kim, A. Heo
KNU, Deagu, Republic of Korea
H. Hayano
KEK, Ibaraki, Japan

Cold cavity BPM was developed to meet high position resolution and bunch to bunch measurement time. It is designed based on re-entrant cavity and has Low-Q to achieve short signal decay time in L-band frequency with large aperture as 78mm. The beam test was performed to demonstrate position resolution at ATF main linac, which is operating with 1.6nC bunch charge, while BPM will be installed inside the ILC cyomodule with 3.2nC spacing 369ns like as ILC at STF. Stripline BPMs, ML2P and ML3P installed upstream and downstream of the BPM’s location respectively were used to predict its position. Reference cavity was optimized to use for synchronous detection. We had achieved ~340nm position resolution since position resolution was estimated due to limitation of system with noise, namely in case of ideal state. We will present configuration of beam test, procedure to measure position resolution and the result on the test. Furthermore, new design will be introduced to improve signal intensity and have heavy coupling.

TUPC161

Cavity Beam Position Monitor System for ATF2

1410

S.T. Boogert, R. Ainsworth, G.E. Boorman, S. Molloy
Royal Holloway, University of London, Surrey, United Kingdom
A.S. Aryshev, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
F.J. Cullinan, N.Y. Joshi, A. Lyapin
JAI, Egham, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White
SLAC, Menlo Park, California, USA
A. Heo, E.-S. Kim, Y.I. Kim
KNU, Deagu, Republic of Korea

The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high resolution C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitizers. In addition 4 high resolution BPMs have been recently installed at the interaction point, we briefly describe the first operational experience of these cavities in the ATF2 beam-line. The current status of the overall BPM system is also described, with a focus on operational techniques and performance.

TUPO033

Emittance Minimization by Courant-Snyder Parameter Scan in Merger Section at the Compact Energy Recovery Linear Accelerator.

1506

J.G. Hwang
Kyungpook National University, Daegu, Republic of Korea
E.-S. Kim
KNU, Deagu, Republic of Korea
T. Miyajima
KEK, Tsukuba, Japan

The project of compact-Energy Recovery Linac(c-ERL) at Photon Factory in KEK is a test facility for the 5 GeV ERL, which is one of the candidates of next generation light source. It consists of injector system, merger section, main SRF section, return arc, long straight section and beam dump. The injector system produces beams with a low-energy of 5 MeV and low-emittance less than 1 mm-mrad. It causes the large emittance growth by space charge force in merger section, which consists of two rectangular type dipole magnets and one sector type magnet. Dispersion also causes the displacement of bunch sllice on horizontal plane. The displacement of bunch slice is laid on the kick angle induced by space charge force. Also, each slice has the orientation of the phase ellipse on horizontal phase space. Therefore, the emittance growth due to the displacement of bunch sllice induced by space charge force in the horizontal phase space can be minimized by matching the displacement to the orientation of the phase ellipse at the exit of merger. We present the results of the emittance minimization performed by mathcing of the angle of the phase ellipse by scan of CS (Courant-Snyder) parameter.

TUPC118

Test Results on Beam Position Resolution for Low-Q IP-BPM at KEK-ATF2

1293

S.W. Jang, A. Heo, J.G. Hwang, E.-S. Kim, H.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
H.K. Park
CHEP, Daegu, Republic of Korea

We have performed the beam tests on the beam position resolution for the Low-Q IP-BPM (Interaction Point-Beam Position Monitor) at ATF2 which is an accelerator test facility for the International Linear Collider. The main goals of KEK-ATF2 are to achieve beam size of 37 nm and beam resolution of nano-meter for beam stabilization. Resolution tests for the Low-Q IP-BPM were performed with KEK BPM doublet in Jan. 2011. We got the results of beam position resolution 70 nm during the experimental periods and will present the detailed experimental procedures and results.