2011 Particle Accelerator Conference - List of Authors (Shchelkunov, S.V.)

Paper	Title	Page
MOP107	Status of Dielectric-Lined Two-Channel Rectangular High Transformer Ratio Accelerator Structure Experiment	298
	S.V. Shchelkunov, M.A. LaPointe Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA M.E. Conde, W. Gai, J.G. Power, Z.M. Yusof ANL, Argonne, USA J.L. Hirshfield Omega-P, Inc., New Haven, Connecticut, USA T.C. Marshall Columbia University, New York, USA D. Mihalcea Northern Illinois University, DeKalb, Illinois, USA G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine
	Funding: This work is supported by DoE, Office of High Energy Physics Recent tests of a two-channel rectangular dielectric lined accelerator structure are described; comparison with theory and related issues are presented. The structure (with channel width ratio 6:1) is designed to have a maximum transformer ratio of ~12.5:1. It operates mainly in the LSM31 mode (~ 30GHz). The dielectric liner is cordierite (dielectric constant ~4.76). The acceleration gradient is 1.2 MV/m for each 10nC of the drive bunch for the first acceleration peak of the wakefield, and 0.92 MV/m for the second peak. The structure is installed into the AWA beam-line (Argonne National Lab) and is excited by a single 10-50nC, 14MeV drive bunch. Both the drive bunch and a delayed witness bunch are produced at the same photocathode. This is the first experiment to test a two-channel dielectric rectangular wakefield device where the accelerated bunch may be continuously energized by the drive bunch. The immediate experimental objective is to observe the energy gain and spread, and thereby draw conclusions from the experimental results and the theory model predictions. The observed energy change of the test bunch might be well explained. G. V. Sotnikov, et al., Advanced Accelerator Concepts: 13th Workshop, Carl B. Schroeder, Wim Leemans and Eric Esarey, editors, AIP Conf. Proc. 1086), pp. 415–420 (AIP, New York, 2009).

TUP073	Development of an L-band Ferroelectric Phase Shifter	955
	S. Kazakov, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA A. Kanareykin, E. Nenasheva Euclid TechLabs, LLC, Solon, Ohio, USA S.V. Shchelkunov Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
	Effective operation of the RF cavities in the superconducting accelerators demands fast, high-power RF vector modulators. Recent progress in development of the new materials, ferroelectrics, having tunable dielectric constant and acceptable losses [] gives the possibility development of such devises. In previous papers [-*] the authors described different L-band ferroelectric phase shifter designs . At low RF level high operation speed of 2 degree/nsec was demonstrated in waveguide phase shifter. However, the experiments show that a special technology is to be developed that provides a good electric contact between ceramics and the metallic wall. In present paper a new design of the fast high–power ferroelectric phase shifter is described based on the simple ferroelectric elements. A. Kanareykin, et al, IPAC 2010, p. 3987 S. Kazakov, et al, “Fast Ferroelectric Phase Shifter Design For ERLs,” 45th ICFA Beam Dynamics Workshop, 2009 * S. Kazakov, et al, PAC2007, p. 599.

Paper

Title

Page

Status of Dielectric-Lined Two-Channel Rectangular High Transformer Ratio Accelerator Structure Experiment

298

S.V. Shchelkunov, M.A. LaPointe
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
M.E. Conde, W. Gai, J.G. Power, Z.M. Yusof
ANL, Argonne, USA
J.L. Hirshfield
Omega-P, Inc., New Haven, Connecticut, USA
T.C. Marshall
Columbia University, New York, USA
D. Mihalcea
Northern Illinois University, DeKalb, Illinois, USA
G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine

Funding: This work is supported by DoE, Office of High Energy Physics
Recent tests of a two-channel rectangular dielectric lined accelerator structure are described; comparison with theory and related issues are presented. The structure (with channel width ratio 6:1) is designed to have a maximum transformer ratio of ~12.5:1. It operates mainly in the LSM31 mode (~ 30GHz). The dielectric liner is cordierite (dielectric constant ~4.76). The acceleration gradient is 1.2 MV/m for each 10nC of the drive bunch for the first acceleration peak of the wakefield, and 0.92 MV/m for the second peak. The structure is installed into the AWA beam-line (Argonne National Lab) and is excited by a single 10-50nC, 14MeV drive bunch. Both the drive bunch and a delayed witness bunch are produced at the same photocathode. This is the first experiment to test a two-channel dielectric rectangular wakefield device where the accelerated bunch may be continuously energized by the drive bunch. The immediate experimental objective is to observe the energy gain and spread, and thereby draw conclusions from the experimental results and the theory model predictions. The observed energy change of the test bunch might be well explained*.
* G. V. Sotnikov, et al., Advanced Accelerator Concepts: 13th Workshop, Carl B. Schroeder, Wim Leemans and Eric Esarey, editors, AIP Conf. Proc. 1086), pp. 415–420 (AIP, New York, 2009).

TUP073

Development of an L-band Ferroelectric Phase Shifter

955

S. Kazakov, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
A. Kanareykin, E. Nenasheva
Euclid TechLabs, LLC, Solon, Ohio, USA
S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA

Effective operation of the RF cavities in the superconducting accelerators demands fast, high-power RF vector modulators. Recent progress in development of the new materials, ferroelectrics, having tunable dielectric constant and acceptable losses [*] gives the possibility development of such devises. In previous papers [**-***] the authors described different L-band ferroelectric phase shifter designs . At low RF level high operation speed of 2 degree/nsec was demonstrated in waveguide phase shifter. However, the experiments show that a special technology is to be developed that provides a good electric contact between ceramics and the metallic wall. In present paper a new design of the fast high–power ferroelectric phase shifter is described based on the simple ferroelectric elements.
* A. Kanareykin, et al, IPAC 2010, p. 3987
** S. Kazakov, et al, “Fast Ferroelectric Phase Shifter Design For ERLs,” 45th ICFA Beam Dynamics Workshop, 2009
*** S. Kazakov, et al, PAC2007, p. 599.