2011 Particle Accelerator Conference - List of Authors (Marhauser, F.)

Paper	Title	Page
WEP085	Beam Breakup Studies for New Cryo-Unit	1633
	S. Ahmed, F.E. Hannon, A.S. Hofler, R. Kazimi, G.A. Krafft, F. Marhauser, B.C. Yunn JLAB, Newport News, Virginia, USA I. Shin University of Connecticut, Storrs, Connecticut, USA
	In this paper, we report the numerical simulations of cumulative beam breakup studies for a new cryo-unit for injector design at Jefferson lab. The system consists of two 1-cell and one 7-cell superconducting RF cavities. The study has been performed using a 2-dimensional time-domain code TDBBU developed in-house. The stability has been confirmed for the present setup of beamline elements with different initial offsets and currents ranging 1 mA - 100 mA.

WEP163	RF Cavity Characterization with VORPAL	1797
	C. Nieter, P.J. Mullowney, C. Roark, P. Stoltz, C.D. Zhou Tech-X, Boulder, Colorado, USA F. Marhauser JLAB, Newport News, Virginia, USA
	When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

THP093	Design Status of MEIC at JLab	2306
	Y. Zhang, S. Ahmed, S.A. Bogacz, P. Chevtsov, Y.S. Derbenev, A. Hutton, G.A. Krafft, R. Li, F. Marhauser, V.S. Morozov, F.C. Pilat, R.A. Rimmer, Y. Roblin, T. Satogata, M. Spata, B. Terzić, M.G. Tiefenback, H. Wang, B.C. Yunn JLAB, Newport News, Virginia, USA S. Abeyratne, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA D.P. Barber Cockcroft Institute, Warrington, Cheshire, United Kingdom A.M. Kondratenko GOO Zaryad, Novosibirsk, Russia S.L. Manikonda, P.N. Ostroumov ANL, Argonne, USA H. K. Sayed ODU, Norfolk, Virginia, USA M.K. Sullivan SLAC, Menlo Park, California, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. An electron-ion collider (MEIC) is envisioned as the primary future of the JLab nuclear science program beyond the 12 GeV upgraded CEBAF. The present MEIC design selects a ring-ring collider option and covers a CM energy range up to 51 GeV for both polarized light ions and un-polarized heavy ions, while higher CM energies could be reached by a future upgrade. The MEIC stored colliding ion beams, which will be generated, accumulated and accelerated in a green field ion complex, are designed to match the stored electron beam injected at full energy from the CEBAF in terms of emittance, bunch length, charge and repetition frequency. This design strategy ensures a high luminosity above 10³⁴ s⁻¹cm^-2. A unique figure-8 shape collider ring is adopted for advantages of preserving ion polarization during acceleration and accommodation of a polarized deuteron beam for collisions. Our recent effort has been focused on completing this conceptual design as well as design optimization of major components. Significant progress has also been made in accelerator R&D including chromatic correction and dynamical aperture, beam-beam, high energy electron cooling and polarization tracking.

Paper

Title

Page

Beam Breakup Studies for New Cryo-Unit

1633

S. Ahmed, F.E. Hannon, A.S. Hofler, R. Kazimi, G.A. Krafft, F. Marhauser, B.C. Yunn
JLAB, Newport News, Virginia, USA
I. Shin
University of Connecticut, Storrs, Connecticut, USA

In this paper, we report the numerical simulations of cumulative beam breakup studies for a new cryo-unit for injector design at Jefferson lab. The system consists of two 1-cell and one 7-cell superconducting RF cavities. The study has been performed using a 2-dimensional time-domain code TDBBU developed in-house. The stability has been confirmed for the present setup of beamline elements with different initial offsets and currents ranging 1 mA - 100 mA.

WEP163

RF Cavity Characterization with VORPAL

1797

C. Nieter, P.J. Mullowney, C. Roark, P. Stoltz, C.D. Zhou
Tech-X, Boulder, Colorado, USA
F. Marhauser
JLAB, Newport News, Virginia, USA

When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

THP093

Design Status of MEIC at JLab

2306

Y. Zhang, S. Ahmed, S.A. Bogacz, P. Chevtsov, Y.S. Derbenev, A. Hutton, G.A. Krafft, R. Li, F. Marhauser, V.S. Morozov, F.C. Pilat, R.A. Rimmer, Y. Roblin, T. Satogata, M. Spata, B. Terzić, M.G. Tiefenback, H. Wang, B.C. Yunn
JLAB, Newport News, Virginia, USA
S. Abeyratne, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA
D.P. Barber
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A.M. Kondratenko
GOO Zaryad, Novosibirsk, Russia
S.L. Manikonda, P.N. Ostroumov
ANL, Argonne, USA
H. K. Sayed
ODU, Norfolk, Virginia, USA
M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
An electron-ion collider (MEIC) is envisioned as the primary future of the JLab nuclear science program beyond the 12 GeV upgraded CEBAF. The present MEIC design selects a ring-ring collider option and covers a CM energy range up to 51 GeV for both polarized light ions and un-polarized heavy ions, while higher CM energies could be reached by a future upgrade. The MEIC stored colliding ion beams, which will be generated, accumulated and accelerated in a green field ion complex, are designed to match the stored electron beam injected at full energy from the CEBAF in terms of emittance, bunch length, charge and repetition frequency. This design strategy ensures a high luminosity above 10³⁴ s⁻¹cm^-2. A unique figure-8 shape collider ring is adopted for advantages of preserving ion polarization during acceleration and accommodation of a polarized deuteron beam for collisions. Our recent effort has been focused on completing this conceptual design as well as design optimization of major components. Significant progress has also been made in accelerator R&D including chromatic correction and dynamical aperture, beam-beam, high energy electron cooling and polarization tracking.