2011 Particle Accelerator Conference - List of Authors (Spentzouris, P.)

Paper	Title	Page
WEP096	Simulations of Space Charge in the Fermilab Main Injector	1654
	E.G. Stern, J.F. Amundson, P. Spentzouris Fermilab, Batavia, USA J. Qiang, R.D. Ryne LBNL, Berkeley, California, USA
	The Fermilab Project X plan for future high intensity running relies on the Main Injector as the engine for delivering protons in the 60-120 GeV energy range. Project X plans call for increasing the number of protons per Main Injector bunch from the current value of 1.0× 10¹¹ to 3.0× 10¹¹. Space charge effects at the injection energy of 8 GeV have the potential to seriously disrupt operations. We report on ongoing simulations with Synergia, our multi-physics process accelerator modeling framework, to model space charge effects in the Main Injector combined with the effects of magnet fringe fields and apertures.

WEP112	Accurate Simulation of the Electron Cloud in the Fermilab Main Injector with VORPAL	1692
	P. Lebrun, P. Spentzouris Fermilab, Batavia, USA J.R. Cary, P. Stolz, S.A. Veitzer Tech-X, Boulder, Colorado, USA
	Precision simulations of the electron cloud at the Fermilab Main Injector (MI) have been studied using the plasma simulation code VORPAL. Fully 3D and self consistent solutions that includes Yee-type E.M. field maps, electron spatial distributions and the time evolution of the cloud with respect to the bunch structure in the MI. The microwave absorption experiment has been simulated in detail and the response of the antennas has been derived from the VORPAL's pseudo-potential data. Based on the results of these simulations and the ongoing experimental program, two distinct new experimental techniques are proposed. The first one is based on the use BPM plates placed in dipole fields and that are made of material(s) for which the secondary emission is well characterized. The second technique would be based on the optical, or ultra-violet, detection of the radiation emitted (inverse photo-electric effect) when the cloud interacts with the inner surface of the beam pipe. As the microwave absorption experiment, this techique is non-invasise and has the advantage of providing spatial images of the cloud as well as accurate timing (ns) information.

WEP147	The Effect of Space-charge and Wake Fields in the Fermilab Booster	1758
	A. Macridin, J.F. Amundson, P. Spentzouris Fermilab, Batavia, USA D.O. McCarron IIT, Chicago, Illinois, USA L.K. Spentzouris Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: This work was supported by the DOE contracts DE-AC02-07CH11359, DE-AC02-05CH11231 and DE-AC02-06CH11357 and the ComPASS project funded through the SciDAC. We calculate the impedance and the wake functions for laminated structures with parallel-planes and circular geometries. We critically examine the approximations used in the literature for the coupling impedance in laminated chambers and find that most of them are not justified because the wall surface impedance is large. A comparison between the flat and the circular geometry impedance is presented. We use the wake fields calculated for the Fermilab Booster laminated magnets in realistic beam simulations using the Synergia code. We find good agreement between our calculation of the coherent tune shift at injection energy and the experimental measurements.

Paper

Title

Page

Simulations of Space Charge in the Fermilab Main Injector

1654

E.G. Stern, J.F. Amundson, P. Spentzouris
Fermilab, Batavia, USA
J. Qiang, R.D. Ryne
LBNL, Berkeley, California, USA

The Fermilab Project X plan for future high intensity running relies on the Main Injector as the engine for delivering protons in the 60-120 GeV energy range. Project X plans call for increasing the number of protons per Main Injector bunch from the current value of 1.0× 10¹¹ to 3.0× 10¹¹. Space charge effects at the injection energy of 8 GeV have the potential to seriously disrupt operations. We report on ongoing simulations with Synergia, our multi-physics process accelerator modeling framework, to model space charge effects in the Main Injector combined with the effects of magnet fringe fields and apertures.

WEP112

Accurate Simulation of the Electron Cloud in the Fermilab Main Injector with VORPAL

1692

P. Lebrun, P. Spentzouris
Fermilab, Batavia, USA
J.R. Cary, P. Stolz, S.A. Veitzer
Tech-X, Boulder, Colorado, USA

Precision simulations of the electron cloud at the Fermilab Main Injector (MI) have been studied using the plasma simulation code VORPAL. Fully 3D and self consistent solutions that includes Yee-type E.M. field maps, electron spatial distributions and the time evolution of the cloud with respect to the bunch structure in the MI. The microwave absorption experiment has been simulated in detail and the response of the antennas has been derived from the VORPAL's pseudo-potential data. Based on the results of these simulations and the ongoing experimental program, two distinct new experimental techniques are proposed. The first one is based on the use BPM plates placed in dipole fields and that are made of material(s) for which the secondary emission is well characterized. The second technique would be based on the optical, or ultra-violet, detection of the radiation emitted (inverse photo-electric effect) when the cloud interacts with the inner surface of the beam pipe. As the microwave absorption experiment, this techique is non-invasise and has the advantage of providing spatial images of the cloud as well as accurate timing (ns) information.

WEP147

The Effect of Space-charge and Wake Fields in the Fermilab Booster

1758

A. Macridin, J.F. Amundson, P. Spentzouris
Fermilab, Batavia, USA
D.O. McCarron
IIT, Chicago, Illinois, USA
L.K. Spentzouris
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: This work was supported by the DOE contracts DE-AC02-07CH11359, DE-AC02-05CH11231 and DE-AC02-06CH11357 and the ComPASS project funded through the SciDAC.
We calculate the impedance and the wake functions for laminated structures with parallel-planes and circular geometries. We critically examine the approximations used in the literature for the coupling impedance in laminated chambers and find that most of them are not justified because the wall surface impedance is large. A comparison between the flat and the circular geometry impedance is presented. We use the wake fields calculated for the Fermilab Booster laminated magnets in realistic beam simulations using the Synergia code. We find good agreement between our calculation of the coherent tune shift at injection energy and the experimental measurements.