IPAC2013 - List of Authors (Terunuma, N.)

Paper

Title

Page

Development of Diamond Sensors for Beam Halo and Compton Spectrum Diagnostics After The Interaction Point of ATF2

470

S. Liu, P. Bambade
LAL, Orsay, France
S. Bai
IHEP, Beijing, People's Republic of China
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major issue at ATF2 and in linear colliders is to control the beam halo, which consists of tails extending far beyond the Gaussian core of the beam. At present there is no dedicated collimation for the beam halo at ATF2, and the transverse distribution near the interaction point is not well known. The development of a sensor based on CVD diamond to scan the beam halo in the vacuum chamber a few meters after the interaction point is presented. This system also aims to detect the Compton recoil electrons generated by the laser interferometer (Shintake monitor) used to measure the beam size at the interaction point of ATF2.

MOPME018

BEAM OSCILLATION MONITOR FOR THE MULTI-BUNCH BEAM

506

T. Naito, S. Araki, H. Hayano, K. Kubo, S. Kuroda, T. Okugi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

In order to observe the motion of bunch-by-bunch beam oscillation of multi-bunch in the storage ring, we developed two measurement tools. One is a signal process electronics circuit using fast analogue switches. The circuit picks up one of the selected bunch signal of the beam position monitor from the multi-bunch. The selected beam position signal can be processed as a single bunch beam. By changing the gate timing, arbitrary bunch signal can be selected. The other is a waveform memory using a high bandwidth oscilloscope. The long waveform memory of the oscilloscope has a capability to acquire the multi-turn waveform of the button electrode signals. The beam test of the circuit has been carried out at KEK-ATF damping ring in the cases of 2.8ns bunch spacing and 5.6ns bunch spacing, respectively. The detail of the hardware and the result of the beam test are reported.

MOPME058

DEVELOPMENT OF A CAVITY-TYPE BEAM POSITION MONITORS WITH HIGH RESOLUTION FOR ATF2

604

S.W. Jang, E.-S. Kim
KNU, Deagu, Republic of Korea
Y. Honda, T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

We have developed a high resolution beam position monitors for ATF2 at KEK, which is an accelerator test facility for International Linear Collider(ILC). The main goals of ATF2 are achievement of 37nm beam size and 2nm beam position resolution for beam stabilization. For these goals, low-Q IP-BPM(Interaction Point Beam Position Monitor) with latency of 20 ns are being developed. In this paper, we will describe about design of Low-Q IP-BPM, the basics test results as RF test and BPM sensitivity test. Electronics for Low-Q IP-BPM will be also described.

MOPWA052

Short Range Wakefield Measurements of High Resolution RF Cavity Beam Position Monitors at ATF2

792

J. Snuverink, S.T. Boogert, F.J. Cullinan, Y.I. Kim, A. Lyapin
JAI, Egham, Surrey, United Kingdom
K. Kubo, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
G.R. White
SLAC, Menlo Park, California, USA

Cavity beam position monitors (CBPM) have been used in several accelerator facilities and are planned to be used in future accelerators and light sources. High position resolution up to tens of nanometres has been achieved, but short range wakefields are a concern, especially for small beam emittances. This paper presents the wakefield calculations as well as the first measurements of the CBPM-generated short range wakefields performed at the Accelerator Test Facility (ATF2).

MOPWA053

Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System

795

L.J. Nevay, G.A. Blair, S.T. Boogert, V. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
L. Corner, R. Walczak
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579
We present the results from the laserwire system at the Accelerator Test Facility 2 (ATF2) during recent operation after relocation to the virtual image point of the ATF2 final focus. The characterisation of the 150 mJ, 77 ps long laser pulses at a scaled virtual interaction point is used to deconvolve the transverse laserwire profile demonstrating a 1.16 ± 0.06 um vertical electron beam profile. Horizontal laserwire scans were used in combination with the vertical scans to measure the electron beam size using a full overlap integral model due to the problems presented by a large aspect ratio electron beam.

MOPWA058

Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2

807

Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin
JAI, Egham, Surrey, United Kingdom
S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
SLAC, Menlo Park, California, USA
Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

TUOCB203

In Vacuum High Accuracy Mechanical Positioning System of Nano Resolution Beam Position Monitor at the Interaction Point of ATF2

1149

P. Bambade, O.R. Blanco, F. Bogard, P. Cornebise, S. Wallon
LAL, Orsay, France
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major goal of ATF2 is to demonstrate the ability to stabilise the beam position at the interaction point, where the beam can be focused down to about 35 nm. For this purpose, a set of new Beam Position Monitors (BPM) has been designed, with an expected resolution of about 2 nm. These BPMs must be very well aligned with respect to the beam, at the few micron level, to fully exploit their fine resolution. In this paper, the mechanical positioning system which has been developed to enable such a precise alignment is presented. It is based on a set of eight piezo actuators with nanometer range displacement resolution, mounted in a new specially made vacuum chamber. Due to the expected resolution of the piezo actuators, this system also brings a new functionality, the possibility to calibrate the BPMs by mechanically scanning the beam.

Slides TUOCB203 [2.276 MB]

TUPME045

Turn-by-turn Measurements in the KEK-ATF

1664

Y. Renier, Y. Papaphilippou, R. Tomás, M. Wendt
CERN, Geneva, Switzerland
N. Eddy
Fermilab, Batavia, USA
K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

The ATF damping ring has been upgraded with new read-out electronics for the beam position monitors (BPM), capable to acquire the beam orbits on a turn-by-turn basis, as well as in a high resolution averaging mode. The new BPM system allows to improve optic corrections and to achieve an even smaller vertical emittance (<2pm). Experimental results are presented based on turn-by-turn beam orbit measurements in the ring, for estimating the beta functions and dispersion along the lattice. A fast method to measure spectral line amplitude in a few turns is also presented, including the evaluation of chromaticity.

WEPWA017

Development of Laser-Compton X-ray Source using Optical Storage Cavity

2165

K. Sakaue, M. Washio
Waseda University, Tokyo, Japan
M.K. Fukuda, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Funding: Work supported by the Quantum Beam Technology Program of MEXT and JSPS Grant-in-Aid for Young Scientists (B) 23740203
We have been developing a pulsed-laser storage technique in a super-cavity for a compact x-ray sources. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. We already obtained a pulse-train x-rays through the laser-Compton scattering between a multi-bunch electron beam and an optical super-cavity. And also, we performed a X-ray imaging via laser-Compton X-ray. On these successful results, we decided to upgrade our system for increasing X-ray flux by 3-order of magnitudes for practical use. For an optical cavity, we designed 4-mirrors bow-tie cavity in order to increase the power. On the other hand, electron accelerator was also upgraded to increase the bunch number in the train. We use 3.6cells rf-gun and 12cell standing wave booster linac. As a result, 2-order increase of X-ray flux was achieved. Design of upgraded our laser-Compton X-ray source, the results of X-ray experiments and future prospective will be presented at the conference.

Paper	Title	Page
MOPME003	Development of Diamond Sensors for Beam Halo and Compton Spectrum Diagnostics After The Interaction Point of ATF2	470
	S. Liu, P. Bambade LAL, Orsay, France S. Bai IHEP, Beijing, People's Republic of China T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major issue at ATF2 and in linear colliders is to control the beam halo, which consists of tails extending far beyond the Gaussian core of the beam. At present there is no dedicated collimation for the beam halo at ATF2, and the transverse distribution near the interaction point is not well known. The development of a sensor based on CVD diamond to scan the beam halo in the vacuum chamber a few meters after the interaction point is presented. This system also aims to detect the Compton recoil electrons generated by the laser interferometer (Shintake monitor) used to measure the beam size at the interaction point of ATF2.

MOPME018	BEAM OSCILLATION MONITOR FOR THE MULTI-BUNCH BEAM	506
	T. Naito, S. Araki, H. Hayano, K. Kubo, S. Kuroda, T. Okugi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	In order to observe the motion of bunch-by-bunch beam oscillation of multi-bunch in the storage ring, we developed two measurement tools. One is a signal process electronics circuit using fast analogue switches. The circuit picks up one of the selected bunch signal of the beam position monitor from the multi-bunch. The selected beam position signal can be processed as a single bunch beam. By changing the gate timing, arbitrary bunch signal can be selected. The other is a waveform memory using a high bandwidth oscilloscope. The long waveform memory of the oscilloscope has a capability to acquire the multi-turn waveform of the button electrode signals. The beam test of the circuit has been carried out at KEK-ATF damping ring in the cases of 2.8ns bunch spacing and 5.6ns bunch spacing, respectively. The detail of the hardware and the result of the beam test are reported.

MOPME058	DEVELOPMENT OF A CAVITY-TYPE BEAM POSITION MONITORS WITH HIGH RESOLUTION FOR ATF2	604
	S.W. Jang, E.-S. Kim KNU, Deagu, Republic of Korea Y. Honda, T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	We have developed a high resolution beam position monitors for ATF2 at KEK, which is an accelerator test facility for International Linear Collider(ILC). The main goals of ATF2 are achievement of 37nm beam size and 2nm beam position resolution for beam stabilization. For these goals, low-Q IP-BPM(Interaction Point Beam Position Monitor) with latency of 20 ns are being developed. In this paper, we will describe about design of Low-Q IP-BPM, the basics test results as RF test and BPM sensitivity test. Electronics for Low-Q IP-BPM will be also described.

MOPWA052	Short Range Wakefield Measurements of High Resolution RF Cavity Beam Position Monitors at ATF2	792
	J. Snuverink, S.T. Boogert, F.J. Cullinan, Y.I. Kim, A. Lyapin JAI, Egham, Surrey, United Kingdom K. Kubo, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan G.R. White SLAC, Menlo Park, California, USA
	Cavity beam position monitors (CBPM) have been used in several accelerator facilities and are planned to be used in future accelerators and light sources. High position resolution up to tens of nanometres has been achieved, but short range wakefields are a concern, especially for small beam emittances. This paper presents the wakefield calculations as well as the first measurements of the CBPM-generated short range wakefields performed at the Accelerator Test Facility (ATF2).

MOPWA053	Sub-Micrometre Resolution Laserwire Transverse Beam Size Measurement System	795
	L.J. Nevay, G.A. Blair, S.T. Boogert, V. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan L. Corner, R. Walczak Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579 We present the results from the laserwire system at the Accelerator Test Facility 2 (ATF2) during recent operation after relocation to the virtual image point of the ATF2 final focus. The characterisation of the 150 mJ, 77 ps long laser pulses at a scaled virtual interaction point is used to deconvolve the transverse laserwire profile demonstrating a 1.16 ± 0.06 um vertical electron beam profile. Horizontal laserwire scans were used in combination with the vertical scans to measure the electron beam size using a full overlap integral model due to the problems presented by a large aspect ratio electron beam.

MOPWA058	Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2	807
	Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin JAI, Egham, Surrey, United Kingdom S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White SLAC, Menlo Park, California, USA Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

TUOCB203	In Vacuum High Accuracy Mechanical Positioning System of Nano Resolution Beam Position Monitor at the Interaction Point of ATF2	1149
	P. Bambade, O.R. Blanco, F. Bogard, P. Cornebise, S. Wallon LAL, Orsay, France T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	ATF2 is a low energy (1.3GeV) prototype of the final focus system for ILC and CLIC linear collider projects. A major goal of ATF2 is to demonstrate the ability to stabilise the beam position at the interaction point, where the beam can be focused down to about 35 nm. For this purpose, a set of new Beam Position Monitors (BPM) has been designed, with an expected resolution of about 2 nm. These BPMs must be very well aligned with respect to the beam, at the few micron level, to fully exploit their fine resolution. In this paper, the mechanical positioning system which has been developed to enable such a precise alignment is presented. It is based on a set of eight piezo actuators with nanometer range displacement resolution, mounted in a new specially made vacuum chamber. Due to the expected resolution of the piezo actuators, this system also brings a new functionality, the possibility to calibrate the BPMs by mechanically scanning the beam.
	Slides TUOCB203 [2.276 MB]

TUPME045	Turn-by-turn Measurements in the KEK-ATF	1664
	Y. Renier, Y. Papaphilippou, R. Tomás, M. Wendt CERN, Geneva, Switzerland N. Eddy Fermilab, Batavia, USA K. Kubo, S. Kuroda, T. Naito, T. Okugi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	The ATF damping ring has been upgraded with new read-out electronics for the beam position monitors (BPM), capable to acquire the beam orbits on a turn-by-turn basis, as well as in a high resolution averaging mode. The new BPM system allows to improve optic corrections and to achieve an even smaller vertical emittance (<2pm). Experimental results are presented based on turn-by-turn beam orbit measurements in the ring, for estimating the beta functions and dispersion along the lattice. A fast method to measure spectral line amplitude in a few turns is also presented, including the evaluation of chromaticity.

WEPWA017	Development of Laser-Compton X-ray Source using Optical Storage Cavity	2165
	K. Sakaue, M. Washio Waseda University, Tokyo, Japan M.K. Fukuda, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Funding: Work supported by the Quantum Beam Technology Program of MEXT and JSPS Grant-in-Aid for Young Scientists (B) 23740203 We have been developing a pulsed-laser storage technique in a super-cavity for a compact x-ray sources. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. We already obtained a pulse-train x-rays through the laser-Compton scattering between a multi-bunch electron beam and an optical super-cavity. And also, we performed a X-ray imaging via laser-Compton X-ray. On these successful results, we decided to upgrade our system for increasing X-ray flux by 3-order of magnitudes for practical use. For an optical cavity, we designed 4-mirrors bow-tie cavity in order to increase the power. On the other hand, electron accelerator was also upgraded to increase the bunch number in the train. We use 3.6cells rf-gun and 12cell standing wave booster linac. As a result, 2-order increase of X-ray flux was achieved. Design of upgraded our laser-Compton X-ray source, the results of X-ray experiments and future prospective will be presented at the conference.