IPAC2012 - List of Authors (Allen, B.A.)

Paper	Title	Page
WEPPP015	Generation and Characterization of 5-micron Electron Beam for Probing Optical Scale Structures	2753
	M.G. Fedurin, M. Babzien, V. Yakimenko BNL, Upton, Long Island, New York, USA B.A. Allen USC, Los Angeles, California, USA P. Muggli MPI, Muenchen, Germany A.Y. Murokh RadiaBeam, Santa Monica, USA
	In recent years advanced acceleration technologies have progress toward combination of electron beam, laser and optical scale dielectric structures. In present paper described generation of the electron beam probe with parameters satisfied to perform test of such optical structures.

WEPPP051	Excitation of Plasma Wakefields with Designer Bunch Trains	2828
	P. Muggli MPI, Muenchen, Germany B.A. Allen, Y. Fang USC, Los Angeles, California, USA M. Babzien, M.G. Fedurin, K. Kusche, R. Malone, C. Swinson, V. Yakimenko BNL, Upton, Long Island, New York, USA
	Funding: Work supported by US Department of Energy. Plasma can sustain multi-GV/m longitudinal electric fields that can be used for particle acceleration. In the plasma wakefield accelerator, or PWFA, the wakefields are driven by a single or a train of electron bunches with length comparable to the plasma wavelength. A train of bunches resonantly driving the wakefields can lead to energy gain by trailing particles many times the energy of the incoming drive train particles (large transformer ratio). In proof-of-principle experiments at the Brookhaven National Laboratory Accelerator Test Facility, we demonstrate by varying the plasma density over four orders of magnitude, and therefore the accelerator frequency over two orders of magnitude (~100GHz to a few THz), that trains with ~ps period resonantly drive wakefields in ~10¹⁶/cc density plasmas. We also demonstrate energy gain by a trailing witness electron bunch that follows the drive train with a variable delay. Detailed experimental results will be presented.

WEPPR089	Experimental Progress: Current Filamentation Instability Study	3141
	B.A. Allen, P. Muggli USC, Los Angeles, California, USA M. Babzien, M.G. Fedurin, K. Kusche, V. Yakimenko BNL, Upton, Long Island, New York, USA C. Huang LANL, Los Alamos, New Mexico, USA J.L. Martins, L.O. Silva IPFN, Lisbon, Portugal W.B. Mori UCLA, Los Angeles, California, USA
	Funding: Work supported by: National Science Foundation and US Department of Energy. Current Filamentation Instability, CFI, is of central importance for the propagation of relativistic electron beams in plasmas. CFI has potential relevance to astrophysics, magnetic field and radiation generation in the afterglow of gamma ray bursts, and inertial confinement fusion, energy transport in the fast-igniter concept. An experimental study of this instability is underway at the Accelerator Test Facility, ATF, at Brookhaven National Laboratory with the 60MeV electron beam and centimeter length capillary discharge plasma. The experimental program includes the systematic study and characterization of the instability as a function of beam (charge, transverse and longitudinal profile) and plasma (plasma density) parameters. Specifically, the transverse beam profile is measured directly at the plasma exit using optical transition radiation from a thin gold-coated silicon window. Experimental results show the reduction of the beam transverse size and the appearance of multiple (1-4) filaments and are a function of the plasma density. We will present simulation and experimental results, provide discussion of these results and outline next steps in the experiment.

Paper

Title

Page

Generation and Characterization of 5-micron Electron Beam for Probing Optical Scale Structures

2753

M.G. Fedurin, M. Babzien, V. Yakimenko
BNL, Upton, Long Island, New York, USA
B.A. Allen
USC, Los Angeles, California, USA
P. Muggli
MPI, Muenchen, Germany
A.Y. Murokh
RadiaBeam, Santa Monica, USA

In recent years advanced acceleration technologies have progress toward combination of electron beam, laser and optical scale dielectric structures. In present paper described generation of the electron beam probe with parameters satisfied to perform test of such optical structures.

WEPPP051

Excitation of Plasma Wakefields with Designer Bunch Trains

2828

P. Muggli
MPI, Muenchen, Germany
B.A. Allen, Y. Fang
USC, Los Angeles, California, USA
M. Babzien, M.G. Fedurin, K. Kusche, R. Malone, C. Swinson, V. Yakimenko
BNL, Upton, Long Island, New York, USA

Funding: Work supported by US Department of Energy.
Plasma can sustain multi-GV/m longitudinal electric fields that can be used for particle acceleration. In the plasma wakefield accelerator, or PWFA, the wakefields are driven by a single or a train of electron bunches with length comparable to the plasma wavelength. A train of bunches resonantly driving the wakefields can lead to energy gain by trailing particles many times the energy of the incoming drive train particles (large transformer ratio). In proof-of-principle experiments at the Brookhaven National Laboratory Accelerator Test Facility, we demonstrate by varying the plasma density over four orders of magnitude, and therefore the accelerator frequency over two orders of magnitude (~100GHz to a few THz), that trains with ~ps period resonantly drive wakefields in ~10¹⁶/cc density plasmas. We also demonstrate energy gain by a trailing witness electron bunch that follows the drive train with a variable delay. Detailed experimental results will be presented.

WEPPR089

Experimental Progress: Current Filamentation Instability Study

3141

B.A. Allen, P. Muggli
USC, Los Angeles, California, USA
M. Babzien, M.G. Fedurin, K. Kusche, V. Yakimenko
BNL, Upton, Long Island, New York, USA
C. Huang
LANL, Los Alamos, New Mexico, USA
J.L. Martins, L.O. Silva
IPFN, Lisbon, Portugal
W.B. Mori
UCLA, Los Angeles, California, USA

Funding: Work supported by: National Science Foundation and US Department of Energy.
Current Filamentation Instability, CFI, is of central importance for the propagation of relativistic electron beams in plasmas. CFI has potential relevance to astrophysics, magnetic field and radiation generation in the afterglow of gamma ray bursts, and inertial confinement fusion, energy transport in the fast-igniter concept. An experimental study of this instability is underway at the Accelerator Test Facility, ATF, at Brookhaven National Laboratory with the 60MeV electron beam and centimeter length capillary discharge plasma. The experimental program includes the systematic study and characterization of the instability as a function of beam (charge, transverse and longitudinal profile) and plasma (plasma density) parameters. Specifically, the transverse beam profile is measured directly at the plasma exit using optical transition radiation from a thin gold-coated silicon window. Experimental results show the reduction of the beam transverse size and the appearance of multiple (1-4) filaments and are a function of the plasma density. We will present simulation and experimental results, provide discussion of these results and outline next steps in the experiment.