PAC2013 - List of Authors (Zholents, A.)

Paper

Title

Page

Analysis of High Repetition Rate Effects in Dielectric Wakefield Accelerators

93

P. Schoessow, S.P. Antipov, C.-J. Jing, A. Kanareykin, S.S. Zuo
Euclid TechLabs, LLC, Solon, Ohio, USA
J.G. Power, A. Zholents
ANL, Argonne, USA

Recently the question has arisen of whether dielectric charging might become a significant limiting effect on the performance of the dielectric wakefield undulator, leading either to deflection of the beam by the static electric field generated, or to catastrophic breakdown of the structure. In experiments to date this has not been problematic with appropriate choice of dielectric material. However, given the high repetition rate that would be required, the device would be subjected to essentially a dc bombardment from the beam halo and thus be vulnerable to these effects because there is no time between machine pulses for discharge of the dielectric. We have begun reexamining this problem, emphasizing the expected charging rate and charge distribution in a thin walled dielectric device and the physics of conductivity and discharge phenomena in a dielectric medium. Simulations of the charging process and halo formation will be presented. We will review early work on beam-induced charging of dielectric structures and also results from deep charging of satellite components by cosmic rays. Ageing and induced conductivity under large radiation doses are also investigated.

MOPHO19

A Tunable Energy Chirp Correction

279

S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Baturin
LETI, Saint-Petersburg, Russia
M.G. Fedurin, C. Swinson
BNL, Upton, Long Island, New York, USA
W. Gai, A. Zholents
ANL, Argonne, USA

Funding: DOE SBIR
Short (subpicosecond) pulses are central to many of the next generation light source initiatives that are based on linear accelerators. Beam compression is performed by means of a chicane utilizing a correlated linear energy chirp. The small energy chirp is kept as the beam goes through the remaining accelerating stage to compensate for wakefield effects. It is necessary to compensate the residual energy spread before the beam enters the undulator stage. We present here a concept for a passive wakefield device- the wakefield silencer- to perform this compensation. We have recently demonstrated a passive energy chirp correction by self-wakefield at the Brookhaven ATF facility. In this paper we present a progress report on development of these tunable chirp correction devices.

TUPMA08

Subpicosecond Bunch Train Production for High Power Tunable THz Source

604

S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
M.G. Fedurin
BNL, Upton, Long Island, New York, USA
W. Gai, A. Zholents
ANL, Argonne, USA
V. Yakimenko
SLAC, Menlo Park, California, USA

Funding: DOE SBIR
An effective method of introducing an energy modulation in an electron bunch by passing it through a dielectric-lined waveguide was recently demonstrated. In the follow up experiment we successfully converted this energy modulation into a density modulation by means of a chicane beamline. The density modulated beam was sent through a foil target, producing THz transition radiation which was characterized using interferometeric techniques. By changing the initial energy chirp of the beam we tuned the center frequency of the generated THz radiation in the range 0.5 - 1 THz. A table top high power narrowband tunable THz source based on this technique is proposed

WEOAA3

APS Superconducting Undulator Beam Commissioning Results

703

K.C. Harkay, L.E. Boon, M. Borland, G. Decker, R.J. Dejus, J.C. Dooling, C.L. Doose, L. Emery, J. Gagliano, E. Gluskin, Q.B. Hasse, Y. Ivanyushenkov, M. Kasa, J.C. Lang, D. Robinson, V. Sajaev, K.M. Schroeder, N. Sereno, Y. Shiroyanagi, D. Skiadopoulos, M.L. Smith, E. Trakhtenberg, A. Xiao, A. Zholents
ANL, Argonne, USA
L.E. Boon
Purdue University, West Lafayette, Indiana, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. All the requirements before operating the SCU0 in the storage ring were satisfied during a short but detailed beam commissioning. The cryogenic system performed very well in the presence of the beam. The total beam-induced heat load on the SCU0 agreed well with the predictions, and the SCU0 is protected from excessive heat loads through a combination of orbit control and SCU0 alignment. When powered, the field integral measured with the beam agreed well with the magnet measurements. An induced quench caused very little beam motion, and did not cause loss of the beam. The device was found to quench during unintentional beam dumps, but quench recovery is transparent to storage ring operation. There were no beam chamber vacuum pressure issues and no negative effect observed on the beam. Finally, the SCU0 was operated well beyond its design requirements, and no significant issues were identified. The beam commissioning results are described in this paper.

Slides WEOAA3 [2.442 MB]

Paper	Title	Page
MOPAC12	Analysis of High Repetition Rate Effects in Dielectric Wakefield Accelerators	93
	P. Schoessow, S.P. Antipov, C.-J. Jing, A. Kanareykin, S.S. Zuo Euclid TechLabs, LLC, Solon, Ohio, USA J.G. Power, A. Zholents ANL, Argonne, USA
	Recently the question has arisen of whether dielectric charging might become a significant limiting effect on the performance of the dielectric wakefield undulator, leading either to deflection of the beam by the static electric field generated, or to catastrophic breakdown of the structure. In experiments to date this has not been problematic with appropriate choice of dielectric material. However, given the high repetition rate that would be required, the device would be subjected to essentially a dc bombardment from the beam halo and thus be vulnerable to these effects because there is no time between machine pulses for discharge of the dielectric. We have begun reexamining this problem, emphasizing the expected charging rate and charge distribution in a thin walled dielectric device and the physics of conductivity and discharge phenomena in a dielectric medium. Simulations of the charging process and halo formation will be presented. We will review early work on beam-induced charging of dielectric structures and also results from deep charging of satellite components by cosmic rays. Ageing and induced conductivity under large radiation doses are also investigated.

MOPHO19	A Tunable Energy Chirp Correction	279
	S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia M.G. Fedurin, C. Swinson BNL, Upton, Long Island, New York, USA W. Gai, A. Zholents ANL, Argonne, USA
	Funding: DOE SBIR Short (subpicosecond) pulses are central to many of the next generation light source initiatives that are based on linear accelerators. Beam compression is performed by means of a chicane utilizing a correlated linear energy chirp. The small energy chirp is kept as the beam goes through the remaining accelerating stage to compensate for wakefield effects. It is necessary to compensate the residual energy spread before the beam enters the undulator stage. We present here a concept for a passive wakefield device- the wakefield silencer- to perform this compensation. We have recently demonstrated a passive energy chirp correction by self-wakefield at the Brookhaven ATF facility. In this paper we present a progress report on development of these tunable chirp correction devices.

TUPMA08	Subpicosecond Bunch Train Production for High Power Tunable THz Source	604
	S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA M.G. Fedurin BNL, Upton, Long Island, New York, USA W. Gai, A. Zholents ANL, Argonne, USA V. Yakimenko SLAC, Menlo Park, California, USA
	Funding: DOE SBIR An effective method of introducing an energy modulation in an electron bunch by passing it through a dielectric-lined waveguide was recently demonstrated. In the follow up experiment we successfully converted this energy modulation into a density modulation by means of a chicane beamline. The density modulated beam was sent through a foil target, producing THz transition radiation which was characterized using interferometeric techniques. By changing the initial energy chirp of the beam we tuned the center frequency of the generated THz radiation in the range 0.5 - 1 THz. A table top high power narrowband tunable THz source based on this technique is proposed

WEOAA3	APS Superconducting Undulator Beam Commissioning Results	703
	K.C. Harkay, L.E. Boon, M. Borland, G. Decker, R.J. Dejus, J.C. Dooling, C.L. Doose, L. Emery, J. Gagliano, E. Gluskin, Q.B. Hasse, Y. Ivanyushenkov, M. Kasa, J.C. Lang, D. Robinson, V. Sajaev, K.M. Schroeder, N. Sereno, Y. Shiroyanagi, D. Skiadopoulos, M.L. Smith, E. Trakhtenberg, A. Xiao, A. Zholents ANL, Argonne, USA L.E. Boon Purdue University, West Lafayette, Indiana, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. All the requirements before operating the SCU0 in the storage ring were satisfied during a short but detailed beam commissioning. The cryogenic system performed very well in the presence of the beam. The total beam-induced heat load on the SCU0 agreed well with the predictions, and the SCU0 is protected from excessive heat loads through a combination of orbit control and SCU0 alignment. When powered, the field integral measured with the beam agreed well with the magnet measurements. An induced quench caused very little beam motion, and did not cause loss of the beam. The device was found to quench during unintentional beam dumps, but quench recovery is transparent to storage ring operation. There were no beam chamber vacuum pressure issues and no negative effect observed on the beam. Finally, the SCU0 was operated well beyond its design requirements, and no significant issues were identified. The beam commissioning results are described in this paper.
	Slides WEOAA3 [2.442 MB]