IBIC2014 - List of Keywords (collider)

Paper	Title	Other Keywords	Page
TUPF02	Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches	electron, simulation, synchrotron-radiation, synchrotron	294
	P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.
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TUPD08	YAG:Ce Screen Monitor Using a Gated CCD Camera	timing, emittance, radiation, synchrotron-radiation	426
	T. Naito, T.M. Mitsuhashi KEK, Ibaraki, Japan
	Due to its good spatial resolution, the YAG:Ce screen monitor is often used for small beam profile measurement in the Linac and beam transport line. We constructed a high-resolution YAG:Ce screen monitor at KEK-ATF2 for the observation of small size beams a. We tested two types of screens, one is powder YAG:Ce and the other is single crystal YAG:Ce. Both screens have 50μm thickness. To escape from strong COTR, we applied delayed timing of the gate for the CCD camera. A microscope having a spatial resolution of 6μm was set outside of a vacuum chamber to observe the scintillation light from the YAG:Ce screen. The results of the difference between the two screens, the camera performance with delayed gate, and the optical performance of the microscope will be presented in this session.
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WEPF05	Simulation of the Beam Dump for a High Intensity Electron Gun	electron, simulation, gun, scattering	536
	A. Jeff, S. Döbert, T. Lefèvre CERN, Geneva, Switzerland A. Jeff The University of Liverpool, Liverpool, United Kingdom K. Pepitone CEA, LE BARP cedex, France
	The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.
	Poster WEPF05 [0.224 MB]
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WEPF16	Algorithm to Improve the Beta-Function Measurement and its Evaluation in Storage Rings Lattices	lattice, storage-ring, betatron, optics	574
	A.C. García-Bonilla UNAL, Bogota D.C, Colombia
	In any beam-line, one of the basic measurements during the beam-diagnostics is the measurement of the Beta-Function along the beam-line. This can be achieved in Storage Ring by taking the tune change obtained when varing the intensity of quadrupoles, or by using the matrix response to fit the corresponding parameters, or by shaking the beam to obtain a betatron motion. In accelerators like the LHC, the Beta-Function measurement is done from the Phase Advance Measurement using the Transfer Matrix. In this paper, a study of a new algorithm or numerically approximation for this measurement is presented, as well as the results of the simulations for the LHC and CLIC damping ring. The deduced and implemented algorithm takes into account a fraction of the both transverse planes measurements. A random (uniform) deviation of the MAD-X phase values is studied, by comparison of the proposed algorithm with the traditional one. An improvement close to 30% and 50% on the global error compare to the traditional way to measure the Beta Function is observed; this is for the studied cases using closed-orbits and phase advance values with deviations of 10 or 20 degrees. Postgraduate Student at Universidad Nacional de Colombia
	Poster WEPF16 [0.742 MB]
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Paper

Title

Other Keywords

Page

TUPF02

Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches

electron, simulation, synchrotron-radiation, synchrotron

294

P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPD08

YAG:Ce Screen Monitor Using a Gated CCD Camera

timing, emittance, radiation, synchrotron-radiation

426

T. Naito, T.M. Mitsuhashi
KEK, Ibaraki, Japan

Due to its good spatial resolution, the YAG:Ce screen monitor is often used for small beam profile measurement in the Linac and beam transport line. We constructed a high-resolution YAG:Ce screen monitor at KEK-ATF2 for the observation of small size beams a. We tested two types of screens, one is powder YAG:Ce and the other is single crystal YAG:Ce. Both screens have 50μm thickness. To escape from strong COTR, we applied delayed timing of the gate for the CCD camera. A microscope having a spatial resolution of 6μm was set outside of a vacuum chamber to observe the scintillation light from the YAG:Ce screen. The results of the difference between the two screens, the camera performance with delayed gate, and the optical performance of the microscope will be presented in this session.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF05

Simulation of the Beam Dump for a High Intensity Electron Gun

electron, simulation, gun, scattering

536

A. Jeff, S. Döbert, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff
The University of Liverpool, Liverpool, United Kingdom
K. Pepitone
CEA, LE BARP cedex, France

The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.

Poster WEPF05 [0.224 MB]

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WEPF16

Algorithm to Improve the Beta-Function Measurement and its Evaluation in Storage Rings Lattices

lattice, storage-ring, betatron, optics

574

A.C. García-Bonilla
UNAL, Bogota D.C, Colombia

In any beam-line, one of the basic measurements during the beam-diagnostics is the measurement of the Beta-Function along the beam-line. This can be achieved in Storage Ring by taking the tune change obtained when varing the intensity of quadrupoles, or by using the matrix response to fit the corresponding parameters, or by shaking the beam to obtain a betatron motion. In accelerators like the LHC, the Beta-Function measurement is done from the Phase Advance Measurement using the Transfer Matrix. In this paper, a study of a new algorithm or numerically approximation for this measurement is presented, as well as the results of the simulations for the LHC and CLIC damping ring. The deduced and implemented algorithm takes into account a fraction of the both transverse planes measurements. A random (uniform) deviation of the MAD-X phase values is studied, by comparison of the proposed algorithm with the traditional one. An improvement close to 30% and 50% on the global error compare to the traditional way to measure the Beta Function is observed; this is for the studied cases using closed-orbits and phase advance values with deviations of 10 or 20 degrees.
Postgraduate Student at Universidad Nacional de Colombia

Poster WEPF16 [0.742 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)