2011 Particle Accelerator Conference - List of Authors (Sotnikov, G.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).

MOP112	Study of Enhanced Transformer Ratio in a Coaxial Dielectric Wakefield Accelerator using a Profiled Drive Bunch Train	304
	G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA T.C. Marshall, G.V. Sotnikov Omega-P, Inc., New Haven, Connecticut, USA
	Funding: The research was supported by US Department of Energy, Office of High Energy Physics, Advanced Accelerator R & D. A key parameter of wakefield acceleration is the transformer ratio T. For a dielectric wakefield accelerator, it has been suggested to use a ramped drive bunch train (RBT), or a multizone dielectric structure to enhance T. Here we show the possibility of greatly improving the RBT technique by the use of a numerical algorithm. We study a two-channel 28 GHz structure with two nested Alumina cylindrical shells (CDWA) which is to be excited by a train of four annular bunches having energy 14 MeV and axial RMS size 1mm; the total charge of bunches is 200 nC. For bunch charge and spacing chosen for optimum acceleration gradient, or for optimizing T using the standard method, we obtain T~3.6. We found that if the charge ratios are 1.0:2.4:3.5:5.0 and the spaces between the bunches are 2.5, 2.5, and 4.5 wakefield periods, then T~17. The RBT also can be used successfully in a high gradient THz CDWA structure. * C.Jing et.al., Phys. Rev. Lett. 98 144801, (2007) C. Wang, et.al. Proc. PAC 2005. IEEE, 2005, p.1333. * G. Sotnikov et.al. PRST-AB, 061302 (2009).

MOP112	Study of Enhanced Transformer Ratio in a Coaxial Dielectric Wakefield Accelerator using a Profiled Drive Bunch Train	304
	G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine J.L. Hirshfield Yale University, Physics Department, New Haven, CT, USA T.C. Marshall, G.V. Sotnikov Omega-P, Inc., New Haven, Connecticut, USA
	Funding: The research was supported by US Department of Energy, Office of High Energy Physics, Advanced Accelerator R & D. A key parameter of wakefield acceleration is the transformer ratio T. For a dielectric wakefield accelerator, it has been suggested to use a ramped drive bunch train (RBT), or a multizone dielectric structure to enhance T. Here we show the possibility of greatly improving the RBT technique by the use of a numerical algorithm. We study a two-channel 28 GHz structure with two nested Alumina cylindrical shells (CDWA) which is to be excited by a train of four annular bunches having energy 14 MeV and axial RMS size 1mm; the total charge of bunches is 200 nC. For bunch charge and spacing chosen for optimum acceleration gradient, or for optimizing T using the standard method, we obtain T~3.6. We found that if the charge ratios are 1.0:2.4:3.5:5.0 and the spaces between the bunches are 2.5, 2.5, and 4.5 wakefield periods, then T~17. The RBT also can be used successfully in a high gradient THz CDWA structure. * C.Jing et.al., Phys. Rev. Lett. 98 144801, (2007) C. Wang, et.al. Proc. PAC 2005. IEEE, 2005, p.1333. * G. Sotnikov et.al. PRST-AB, 061302 (2009).

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).

MOP112

Study of Enhanced Transformer Ratio in a Coaxial Dielectric Wakefield Accelerator using a Profiled Drive Bunch Train

304

G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, Connecticut, USA

Funding: The research was supported by US Department of Energy, Office of High Energy Physics, Advanced Accelerator R & D.
A key parameter of wakefield acceleration is the transformer ratio T. For a dielectric wakefield accelerator, it has been suggested to use a ramped drive bunch train (RBT), or a multizone dielectric structure to enhance T. Here we show the possibility of greatly improving the RBT technique by the use of a numerical algorithm. We study a two-channel 28 GHz structure with two nested Alumina cylindrical shells (CDWA) which is to be excited by a train of four annular bunches having energy 14 MeV and axial RMS size 1mm; the total charge of bunches is 200 nC. For bunch charge and spacing chosen for optimum acceleration gradient, or for optimizing T using the standard method, we obtain T~3.6. We found that if the charge ratios are 1.0:2.4:3.5:5.0 and the spaces between the bunches are 2.5, 2.5, and 4.5 wakefield periods, then T~17. The RBT also can be used successfully in a high gradient THz CDWA structure.
* C.Jing et.al., Phys. Rev. Lett. 98 144801, (2007)
** C. Wang, et.al. Proc. PAC 2005. IEEE, 2005, p.1333.
*** G. Sotnikov et.al. PRST-AB, 061302 (2009).

MOP112

Study of Enhanced Transformer Ratio in a Coaxial Dielectric Wakefield Accelerator using a Profiled Drive Bunch Train

304

G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, Connecticut, USA

Funding: The research was supported by US Department of Energy, Office of High Energy Physics, Advanced Accelerator R & D.
A key parameter of wakefield acceleration is the transformer ratio T. For a dielectric wakefield accelerator, it has been suggested to use a ramped drive bunch train (RBT), or a multizone dielectric structure to enhance T. Here we show the possibility of greatly improving the RBT technique by the use of a numerical algorithm. We study a two-channel 28 GHz structure with two nested Alumina cylindrical shells (CDWA) which is to be excited by a train of four annular bunches having energy 14 MeV and axial RMS size 1mm; the total charge of bunches is 200 nC. For bunch charge and spacing chosen for optimum acceleration gradient, or for optimizing T using the standard method, we obtain T~3.6. We found that if the charge ratios are 1.0:2.4:3.5:5.0 and the spaces between the bunches are 2.5, 2.5, and 4.5 wakefield periods, then T~17. The RBT also can be used successfully in a high gradient THz CDWA structure.
* C.Jing et.al., Phys. Rev. Lett. 98 144801, (2007)
** C. Wang, et.al. Proc. PAC 2005. IEEE, 2005, p.1333.
*** G. Sotnikov et.al. PRST-AB, 061302 (2009).