IPAC2012 - List of Keywords (collective-effects)

Paper	Title	Other Keywords	Page
MOPPC075	A Generic Data Model for HeadTail: Design and Implementation with Examples	electron, simulation, HOM, wakefield	307
	K.S.B. Li, G. Rumolo CERN, Geneva, Switzerland
	HeadTail has been developed in 2002 for the efficient simulation of instabilities and collective effects in large circular accelerators. Since then, the capabilities of the code have been continuously extended and the output data has become increasingly complex and large-scale ranging from the statistical description of single bunches to the statistical description of all slices within bunches up to the dynamics of the full 6D phase space over several thousands of turns. Processing this data in an effective manner and endowing it with a structure that provides a physical concept calls for new and optimised data formats. To meet state-of-the-art standards, the hierarchical data format (HDF5) has been selected as native output data format together with H5Part and XDMF as native data structures. We describe the implementation of the H5Part and the XDMF data structures into HeadTail and show some illustrative examples for data processing.

TUEPPB007	A Self Consistent Multiprocessor Space Charge Algorithm that is Almost Embarrassingly Parallel	space-charge, simulation, factory, brightness	1128
	E.W. Nissen JLAB, Newport News, Virginia, USA B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA S.L. Manikonda ANL, Argonne, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We present a space charge code that is self consistent, massively parallelizeable, and requires very little communication between the computer nodes; making the calculation almost embarrassingly parallel. This method is implemented in the code COSY Infinity where the differential algebras used in this code are important to the algorithm's proper functioning. The method works by calculating the self consistent charge distribution using the statistical moments of the test particles, and converting them into polynomial series coefficients. These coefficients are combined with differential algebraic integrals to form the potential, and electric fields. The result is a transfer map which contains the effects of space charge. This method allows for massive parallelization since its statistics based solver doesn’t require any binning of the particles, and only requires a vector containing the partial sums of the statistical moments for the different nodes to be passed. All other calculations are done independently. The resulting maps can be used to analyze the system using normal form analysis, as well as advance particles in numbers and at speeds that were previously impossible.

WEPPR033	Performance of Low-Energy Magnetic Bunch Compression for the ASTA Photoinjector at Fermilab	simulation, dipole, emittance, cryomodule	3006
	C.R. Prokop, P. Piot Northern Illinois University, DeKalb, Illinois, USA B.E. Carlsten LANL, Los Alamos, New Mexico, USA M.D. Church Fermilab, Batavia, USA
	Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359. The Advanced Superconducting Test Accelerator (ASTA) at Fermilab incorporates a magnetic bunch compressor chicane to compress the 40-MeV electron bunches generated in the photoinjector. In this paper, we present a numerical analysis and parametric study of the bunch compressor's performance for various operating scenarios. The beam dynamics simulations, carried out with Astra, Impact-Z and CSRTrack, are compared against each other. Finally, an operating regime with low phase space dilutions is suggested based on the simulation results.

WEPPR057	On the Single Bunch Longitudinal Collective Effects in BEPCII	impedance, electron, storage-ring, controls	3054
	D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang IHEP, Beijing, People's Republic of China
	Funding: National Natural Science Foundation of China,project 11175192. In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

WEPPR081	The Collective Effects of the Short Pulsed X-Ray (SPX) System in the Advanced Photon Source Upgrade	impedance, cavity, simulation, emittance	3117
	Y.-C. Chae, M. Borland ANL, Argonne, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357. The Advanced Photon Source is a 7-GeV hard x-ray synchrotron light source. The APS Upgrade specifies a short-pulse x-ray (SPX) as well as additional beamlines delivering higher brightness and flux. In order to achieve this goal we plan to use S-band superconducting cavities. The performance of such a system based on the zero-current simulation is well established; here, we included the effect of wakefields generated by the SPX system. While the SPX system is off, we are interested in how much current we can store in the single bunch, because the SPX contributes a significant amount of broadband impedance to the ring. With the SPX system on, we are interested in how much vertical emittance will increase, which in turn will enlarge the x-ray pulse length. We report the results of both cases when the SPX system is installed in the ring for the APS Upgrade.

WEPPR082	The Collective Effects of Long Straight Sections (LSSs) in the Advanced Photon Source Upgrade	impedance, undulator, storage-ring, injection	3120
	Y.-C. Chae, L.H. Morrison ANL, Argonne, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357. The Advanced Photon Source is a 7-GeV hard x-ray synchrotron light source. The APS Upgrade specifies additional beamlines delivering higher brightness and flux as well as for the short-pulse x-ray (SPX). In order to fulfill these demands we plan to provide long straight sections (LSS), for which the total length of the insertion devices is increased to 7.7m. The long straight section also helps in implementing the SPX scheme without removing insertion devices. However, the impedance of the LSS may reduce the single-bunch current of 16 mA per bunch delivered to the users during hybrid fill. We estimate the effect of LSS impedance on the bunched beam current and propose an impedance optimization of the undulator chamber with a small gap.

Paper

Title

Other Keywords

Page

MOPPC075

A Generic Data Model for HeadTail: Design and Implementation with Examples

electron, simulation, HOM, wakefield

307

K.S.B. Li, G. Rumolo
CERN, Geneva, Switzerland

HeadTail has been developed in 2002 for the efficient simulation of instabilities and collective effects in large circular accelerators. Since then, the capabilities of the code have been continuously extended and the output data has become increasingly complex and large-scale ranging from the statistical description of single bunches to the statistical description of all slices within bunches up to the dynamics of the full 6D phase space over several thousands of turns. Processing this data in an effective manner and endowing it with a structure that provides a physical concept calls for new and optimised data formats. To meet state-of-the-art standards, the hierarchical data format (HDF5) has been selected as native output data format together with H5Part and XDMF as native data structures. We describe the implementation of the H5Part and the XDMF data structures into HeadTail and show some illustrative examples for data processing.

TUEPPB007

A Self Consistent Multiprocessor Space Charge Algorithm that is Almost Embarrassingly Parallel

space-charge, simulation, factory, brightness

1128

E.W. Nissen
JLAB, Newport News, Virginia, USA
B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
S.L. Manikonda
ANL, Argonne, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We present a space charge code that is self consistent, massively parallelizeable, and requires very little communication between the computer nodes; making the calculation almost embarrassingly parallel. This method is implemented in the code COSY Infinity where the differential algebras used in this code are important to the algorithm's proper functioning. The method works by calculating the self consistent charge distribution using the statistical moments of the test particles, and converting them into polynomial series coefficients. These coefficients are combined with differential algebraic integrals to form the potential, and electric fields. The result is a transfer map which contains the effects of space charge. This method allows for massive parallelization since its statistics based solver doesn’t require any binning of the particles, and only requires a vector containing the partial sums of the statistical moments for the different nodes to be passed. All other calculations are done independently. The resulting maps can be used to analyze the system using normal form analysis, as well as advance particles in numbers and at speeds that were previously impossible.

WEPPR033

Performance of Low-Energy Magnetic Bunch Compression for the ASTA Photoinjector at Fermilab

simulation, dipole, emittance, cryomodule

3006

C.R. Prokop, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
B.E. Carlsten
LANL, Los Alamos, New Mexico, USA
M.D. Church
Fermilab, Batavia, USA

Funding: LANL LDRD program, project 20110067DR -U.S. DOE Contract No. DE-FG02-08ER41532 and DE-AC02-07CH11359.
The Advanced Superconducting Test Accelerator (ASTA) at Fermilab incorporates a magnetic bunch compressor chicane to compress the 40-MeV electron bunches generated in the photoinjector. In this paper, we present a numerical analysis and parametric study of the bunch compressor's performance for various operating scenarios. The beam dynamics simulations, carried out with Astra, Impact-Z and CSRTrack, are compared against each other. Finally, an operating regime with low phase space dilutions is suggested based on the simulation results.

WEPPR057

On the Single Bunch Longitudinal Collective Effects in BEPCII

impedance, electron, storage-ring, controls

3054

D. Wang, Z. Duan, J. Gao, Y. Li, L. Wang, L. Wang, N. Wang
IHEP, Beijing, People's Republic of China

Funding: National Natural Science Foundation of China,project 11175192.
In order to study the single bunch longitudinal instability in BEPCII, experiments on the bunch lengthening phenomenon were made. By analyzing the experimental data based on the Gao’s theory, the longitudinal loss factor for the bunch are obtained. Also, the total wake potential and the inductance of the machine are estimated.

WEPPR081

The Collective Effects of the Short Pulsed X-Ray (SPX) System in the Advanced Photon Source Upgrade

impedance, cavity, simulation, emittance

3117

Y.-C. Chae, M. Borland
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357.
The Advanced Photon Source is a 7-GeV hard x-ray synchrotron light source. The APS Upgrade specifies a short-pulse x-ray (SPX) as well as additional beamlines delivering higher brightness and flux. In order to achieve this goal we plan to use S-band superconducting cavities. The performance of such a system based on the zero-current simulation is well established; here, we included the effect of wakefields generated by the SPX system. While the SPX system is off, we are interested in how much current we can store in the single bunch, because the SPX contributes a significant amount of broadband impedance to the ring. With the SPX system on, we are interested in how much vertical emittance will increase, which in turn will enlarge the x-ray pulse length. We report the results of both cases when the SPX system is installed in the ring for the APS Upgrade.

WEPPR082

The Collective Effects of Long Straight Sections (LSSs) in the Advanced Photon Source Upgrade

impedance, undulator, storage-ring, injection

3120

Y.-C. Chae, L.H. Morrison
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357.
The Advanced Photon Source is a 7-GeV hard x-ray synchrotron light source. The APS Upgrade specifies additional beamlines delivering higher brightness and flux as well as for the short-pulse x-ray (SPX). In order to fulfill these demands we plan to provide long straight sections (LSS), for which the total length of the insertion devices is increased to 7.7m. The long straight section also helps in implementing the SPX scheme without removing insertion devices. However, the impedance of the LSS may reduce the single-bunch current of 16 mA per bunch delivered to the users during hybrid fill. We estimate the effect of LSS impedance on the bunched beam current and propose an impedance optimization of the undulator chamber with a small gap.