DIPAC2011 - List of Keywords (gun)

Paper	Title	Other Keywords	Page
MOPD04	RHIC Electron Lens Test Bench Diagnostics	electron, ion, diagnostics, solenoid	38
	D.M. Gassner, E.N. Beebe, W. Fischer, X. Gu, K. Hamdi, J. Hock, C. Liu, T.A. Miller, A.I. Pikin, P. Thieberger BNL, Upton, Long Island, New York, USA
	An Electron Lens system will be installed in RHIC to increase luminosity by counteracting the head-on beam-beam interaction. The proton beam collisions at the two experimental locations will introduce a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam will be used to improve luminosity and lifetime of the colliding beams by reducing the betatron tune shift and spread. In preparation for the Electron Lens installation next year, a test bench facility will be used to gain experience with all sub-systems. This paper will discuss the diagnostics related to measuring the electron beam parameters.

MOPD31	Future Timing and Synchronization Scheme at ELBE	laser, electron, radiation, controls	116
	M. Kuntzsch, A. Büchner, T. Kirschke, U. Lehnert, F. Röser HZDR, Dresden, Germany
	The Radiation Source ELBE at Helmholtz-Zentrum Dresden-Rossendorf is currently extended to offer capacity for new experiments. The reconstruction includes the setup of a THz-beamline with a dedicated user laboratory and a beamline for electron-beam - high-power laser experiments. The current synchronization scheme offers stability to the picoseconds level. The new experiments require a femtosecond synchronization in order to get field-strength resolved THz-probes and to have a stable overlap between the electron-bunches with the laser pulses. In the future there will be a MIT/DESY-like system [1] with a pulsed fiber laser as an optical reference oscillator. The laser pulses will be distributed over stabilized fiber links to the remote stations. Later on it is planned to install EOM-based beam arrival time monitors (BAMs) in order to monitor the bunch jitter and to establish a feedback system to reduce the jitter. Besides that, the timing system has to be revised to trigger experiments with low repetition rate, two guns (thermionic DC, superconducting RF) and lasers. The Poster will show the Layout of the possible future Timing and Synchronization System at ELBE. [1] J. Kim, J.A. Cox, J.J. Chen, F.X. Kärtner, "Drift-free femtosecond timing synchronization of remote optical and microwave sources", Nature Photonics, Vol. 2, pp. 733-736 (2008).

TUPD07	Instrumentation Needs and Solutions for the Development of an SRF Photoelectron Injector at the Energy-Recovery Linac BERLinPro	emittance, SRF, laser, cavity	317
	R. Barday, T. Kamps, A. Neumann, J. Rudolph, S.G. Schubert, J. Völker HZB, Berlin, Germany A. Ferrarotto, T. Weis DELTA, Dortmund, Germany
	BERLinPro is an energy-recovery linac for an electron beam with 1 mm mrad normalized emittance and 100 mA average current. The initial beam parameters are determined by the performance of the electron source, an SRF photo-electron injector. Development of this source is a major part of the BERLinPro programme. The instrumentation for the first stage of the programme serves the purpose to have robust and reliable monitors for fundamental beam parameters like emittance, bunch charge, energy and energy spread. The critical issue of the second stage is the generation of an electron beam with 100 mA average current and a normalized emittance of 1 mm mrad. Therefore we plan to setup a dedicated instrumentation beamline with a compact DC gun to measure thermal emittance, current and current lifetime. In parallel an SRF gun with dedicated diagnostics will be build focused on ERL specific aspects like emittance compensation with low-energy beams and reliability of high current operation. This paper collects requirements for each development stage and discusses solutions to specific measurement problems.

TUPD30	Bunch Length Measurement using Coherent Cherenkov Radiation	electron, laser, linac, injection	368
	K. Kan, T. Kondoh, T. Kozawa, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	Ultra-short electron bunches on the order of 100 fs or less can be used in the study of ultrafast reactions and phenomena in time-resolved pump-probe experiments involving the application of techniques such as pulse radiolysis. Such electron bunches are also useful for electro-magnetic (EM) radiation production, where the frequency of EM radiation depends on the electron bunch length. In this presentation, Coherent Cherenkov Radiation (CCR), which is a method of THz radiation emitted from relativistic electron bunches, was studied for a diagnostic of electron bunch length. A picosecond electron bunch generated by a photocahode radio frequency (RF) gun was used. CCR can emit narrow-band THz wave with a dielectric-lined waveguide structure. The intensity and frequency of CCR were measured by a Michelson interferometer and a 4.2K liquid-He cooled bolometer.

TUPD68	Feasibility Study for a Single-Shot 3D Electron Bunch Charge Distribution Monitor with a Polarized Probe Laser at SPring-8 Photoinjector	laser, polarization, electron, monitoring	464
	Y. Okayasu, H. Dewa, H. Hanaki, S. Matsubara, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan T. Ishikawa RIKEN Spring-8 Harima, Hyogo, Japan A. Maekawa, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
	It is essential for precise characterizations of light sources to monitor ever-changing charge distribution of electron bunch by single-shot measurement with high resolutions. Therefore, a single-shot and non-destructive 3D bunch charge distribution (BCD) monitor was developed to characterize longitudinal and transverse BCDs simultaneously. It is based on Electro-Optical (EO) multiple sampling with a manner of spectral decoding. For the transverse detection, eight EO-crystals surround the beam axis azimuthally, and a linear-chirped probe laser pulse with a hollow shape and spirally temporal shift, passes through the EO-crystals. A principle verification experiment has been successfully carried out with two EO-crystals in our facility. In addition, we are promoting a numerical calculation of the ultra-short and radial polarized laser transportation for our own system assuming eight EO-crystals usage in order to confirm observation feasibility. We report the principle and the first experimental results of the novel 3D-BCD monitor and introduce the feasibility demonstration with a calculation about a propagation of transverse polarization distributions along probe laser optics.
	Poster TUPD68 [4.684 MB]

TUPD85	Photoinjector Based MeV Electron Microscopy	electron, emittance, laser, cathode	503
	J. Yang, K. Kan, T. Kondoh, Y. Yoshida ISIR, Osaka, Japan J. Urakawa KEK, Ibaraki, Japan
	A time-resolved MeV electron microscopy based on a photocathode rf electron gun is being developed in Osaka University to reveal the hidden dynamics of intricate molecular and atomic processes in materials. A new structure rf gun has been developed to generates a high-brightness femtosecond-bunch electron beam. The microscopy has been used successfully for the single-shot MeV electron diffraction measurement and the time-resolved measurement. The transverse emittance, bunch length and energy spread were diagnosed as the functions of the laser injection phase, the laser pulse width and the bunch charge. The growths of the emittance, bunch length and energy spread due to the rf and the space charge effects in the rf gun were investigated.

TUPD86	RF Reference Distribution and Timing System for the Taiwan Photon Source	linac, controls, synchrotron, booster	506
	C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.-Y. Liao NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m (24 straight sections for installation of insertion devices), radio-frequency cavities and electron beam from the 150 MeV linac system which being in construction at National Synchrotron Radiation Research Center (NSRRC) campus. A high stability of the novel fiber based 500 MHz RF reference distribution is required and planned to use. Timing system for the TPS will be an event based system. It is based on 6U CompactPCI form factor from Micro-Research Finland Oy. Prototyping of the RF distribution and event system are on progress in this direction. The preliminary test results and implementation details will summary in this report.

TUPD88	A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron	electron, proton, synchrotron, diagnostics	512
	A. Pertica, S.J. Payne STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.
	Poster TUPD88 [1.793 MB]

Paper

Title

Other Keywords

Page

MOPD04

RHIC Electron Lens Test Bench Diagnostics

electron, ion, diagnostics, solenoid

38

D.M. Gassner, E.N. Beebe, W. Fischer, X. Gu, K. Hamdi, J. Hock, C. Liu, T.A. Miller, A.I. Pikin, P. Thieberger
BNL, Upton, Long Island, New York, USA

An Electron Lens system will be installed in RHIC to increase luminosity by counteracting the head-on beam-beam interaction. The proton beam collisions at the two experimental locations will introduce a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam will be used to improve luminosity and lifetime of the colliding beams by reducing the betatron tune shift and spread. In preparation for the Electron Lens installation next year, a test bench facility will be used to gain experience with all sub-systems. This paper will discuss the diagnostics related to measuring the electron beam parameters.

MOPD31

Future Timing and Synchronization Scheme at ELBE

laser, electron, radiation, controls

116

M. Kuntzsch, A. Büchner, T. Kirschke, U. Lehnert, F. Röser
HZDR, Dresden, Germany

The Radiation Source ELBE at Helmholtz-Zentrum Dresden-Rossendorf is currently extended to offer capacity for new experiments. The reconstruction includes the setup of a THz-beamline with a dedicated user laboratory and a beamline for electron-beam - high-power laser experiments. The current synchronization scheme offers stability to the picoseconds level. The new experiments require a femtosecond synchronization in order to get field-strength resolved THz-probes and to have a stable overlap between the electron-bunches with the laser pulses. In the future there will be a MIT/DESY-like system [1] with a pulsed fiber laser as an optical reference oscillator. The laser pulses will be distributed over stabilized fiber links to the remote stations. Later on it is planned to install EOM-based beam arrival time monitors (BAMs) in order to monitor the bunch jitter and to establish a feedback system to reduce the jitter. Besides that, the timing system has to be revised to trigger experiments with low repetition rate, two guns (thermionic DC, superconducting RF) and lasers. The Poster will show the Layout of the possible future Timing and Synchronization System at ELBE.
[1] J. Kim, J.A. Cox, J.J. Chen, F.X. Kärtner, "Drift-free femtosecond timing synchronization of remote optical and microwave sources", Nature Photonics, Vol. 2, pp. 733-736 (2008).

TUPD07

Instrumentation Needs and Solutions for the Development of an SRF Photoelectron Injector at the Energy-Recovery Linac BERLinPro

emittance, SRF, laser, cavity

317

R. Barday, T. Kamps, A. Neumann, J. Rudolph, S.G. Schubert, J. Völker
HZB, Berlin, Germany
A. Ferrarotto, T. Weis
DELTA, Dortmund, Germany

BERLinPro is an energy-recovery linac for an electron beam with 1 mm mrad normalized emittance and 100 mA average current. The initial beam parameters are determined by the performance of the electron source, an SRF photo-electron injector. Development of this source is a major part of the BERLinPro programme. The instrumentation for the first stage of the programme serves the purpose to have robust and reliable monitors for fundamental beam parameters like emittance, bunch charge, energy and energy spread. The critical issue of the second stage is the generation of an electron beam with 100 mA average current and a normalized emittance of 1 mm mrad. Therefore we plan to setup a dedicated instrumentation beamline with a compact DC gun to measure thermal emittance, current and current lifetime. In parallel an SRF gun with dedicated diagnostics will be build focused on ERL specific aspects like emittance compensation with low-energy beams and reliability of high current operation. This paper collects requirements for each development stage and discusses solutions to specific measurement problems.

TUPD30

Bunch Length Measurement using Coherent Cherenkov Radiation

electron, laser, linac, injection

368

K. Kan, T. Kondoh, T. Kozawa, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Ultra-short electron bunches on the order of 100 fs or less can be used in the study of ultrafast reactions and phenomena in time-resolved pump-probe experiments involving the application of techniques such as pulse radiolysis. Such electron bunches are also useful for electro-magnetic (EM) radiation production, where the frequency of EM radiation depends on the electron bunch length. In this presentation, Coherent Cherenkov Radiation (CCR), which is a method of THz radiation emitted from relativistic electron bunches, was studied for a diagnostic of electron bunch length. A picosecond electron bunch generated by a photocahode radio frequency (RF) gun was used. CCR can emit narrow-band THz wave with a dielectric-lined waveguide structure. The intensity and frequency of CCR were measured by a Michelson interferometer and a 4.2K liquid-He cooled bolometer.

TUPD68

Feasibility Study for a Single-Shot 3D Electron Bunch Charge Distribution Monitor with a Polarized Probe Laser at SPring-8 Photoinjector

laser, polarization, electron, monitoring

464

Y. Okayasu, H. Dewa, H. Hanaki, S. Matsubara, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan
T. Ishikawa
RIKEN Spring-8 Harima, Hyogo, Japan
A. Maekawa, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan

It is essential for precise characterizations of light sources to monitor ever-changing charge distribution of electron bunch by single-shot measurement with high resolutions. Therefore, a single-shot and non-destructive 3D bunch charge distribution (BCD) monitor was developed to characterize longitudinal and transverse BCDs simultaneously. It is based on Electro-Optical (EO) multiple sampling with a manner of spectral decoding. For the transverse detection, eight EO-crystals surround the beam axis azimuthally, and a linear-chirped probe laser pulse with a hollow shape and spirally temporal shift, passes through the EO-crystals. A principle verification experiment has been successfully carried out with two EO-crystals in our facility. In addition, we are promoting a numerical calculation of the ultra-short and radial polarized laser transportation for our own system assuming eight EO-crystals usage in order to confirm observation feasibility. We report the principle and the first experimental results of the novel 3D-BCD monitor and introduce the feasibility demonstration with a calculation about a propagation of transverse polarization distributions along probe laser optics.

Poster TUPD68 [4.684 MB]

TUPD85

Photoinjector Based MeV Electron Microscopy

electron, emittance, laser, cathode

503

J. Yang, K. Kan, T. Kondoh, Y. Yoshida
ISIR, Osaka, Japan
J. Urakawa
KEK, Ibaraki, Japan

A time-resolved MeV electron microscopy based on a photocathode rf electron gun is being developed in Osaka University to reveal the hidden dynamics of intricate molecular and atomic processes in materials. A new structure rf gun has been developed to generates a high-brightness femtosecond-bunch electron beam. The microscopy has been used successfully for the single-shot MeV electron diffraction measurement and the time-resolved measurement. The transverse emittance, bunch length and energy spread were diagnosed as the functions of the laser injection phase, the laser pulse width and the bunch charge. The growths of the emittance, bunch length and energy spread due to the rf and the space charge effects in the rf gun were investigated.

TUPD86

RF Reference Distribution and Timing System for the Taiwan Photon Source

linac, controls, synchrotron, booster

506

C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.-Y. Liao
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m (24 straight sections for installation of insertion devices), radio-frequency cavities and electron beam from the 150 MeV linac system which being in construction at National Synchrotron Radiation Research Center (NSRRC) campus. A high stability of the novel fiber based 500 MHz RF reference distribution is required and planned to use. Timing system for the TPS will be an event based system. It is based on 6U CompactPCI form factor from Micro-Research Finland Oy. Prototyping of the RF distribution and event system are on progress in this direction. The preliminary test results and implementation details will summary in this report.

TUPD88

A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron

electron, proton, synchrotron, diagnostics

512

A. Pertica, S.J. Payne
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.

Poster TUPD88 [1.793 MB]