skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Towards a Practical Multi-Meter Long Dielectric Wakefield Accelerator: Problems and Solutions

Authors:
 [1];  [1];  [2]
  1. Los Alamos National Laboratory
  2. ANL
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1296703
Report Number(s):
LA-UR-16-25998
DOE Contract Number:
AC52-06NA25396
Resource Type:
Conference
Resource Relation:
Conference: Advanced Accelerator Concepts Workshop ; 2016-08-01 - 2016-08-01 ; National Harbor, Maryland, United States
Country of Publication:
United States
Language:
English
Subject:
Accelerator Design, Technology, and Operations

Citation Formats

Simakov, Evgenya Ivanovna, Shchegolkov, Dmitry, and Zholents, Alexander. Towards a Practical Multi-Meter Long Dielectric Wakefield Accelerator: Problems and Solutions. United States: N. p., 2016. Web.
Simakov, Evgenya Ivanovna, Shchegolkov, Dmitry, & Zholents, Alexander. Towards a Practical Multi-Meter Long Dielectric Wakefield Accelerator: Problems and Solutions. United States.
Simakov, Evgenya Ivanovna, Shchegolkov, Dmitry, and Zholents, Alexander. Thu . "Towards a Practical Multi-Meter Long Dielectric Wakefield Accelerator: Problems and Solutions". United States. doi:. https://www.osti.gov/servlets/purl/1296703.
@article{osti_1296703,
title = {Towards a Practical Multi-Meter Long Dielectric Wakefield Accelerator: Problems and Solutions},
author = {Simakov, Evgenya Ivanovna and Shchegolkov, Dmitry and Zholents, Alexander},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Aug 04 00:00:00 EDT 2016},
month = {Thu Aug 04 00:00:00 EDT 2016}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • The Argonne Wakefield Accelerator (AWA) is a facility designed to investigate high gradient wakefield acceleration techniques. Wakefields are excited using a drive beam produced by a 14 MeV high current photoinjector-based linac. A second photocathode gun generates a 4 MeV witness beam which is used as a probe of the wakefields in the device under test. The delay of the witness bunch with respect to the drive bunch can be continuously varied from -100 ps to >1 ns. The drive and witness bunches propagate along collinear or parallel trajectories through the test section. A dipole spectrometer is then used tomore » measure the energy change of the witness beam. The complete wakefield measurement system has been commissioned and wakefield experiments using dielectric structures are underway. Initial experiments have focused on collinear wakefield device geometries where the drive and witness bunches traverse the same structure. For attaining very high gradients we will construct and study step-up transformer structures in which the rf pulse generated by the drive beam is compressed transversely and longitudinally.« less
  • No abstract prepared.
  • In the E-157 experiment now being conducted at the Stanford Linear Accelerator Center (SLAC), a 30 GeV electron beam of 2 x 10{sup 10} electrons in a 0.65mm long bunch is propagated through a 1.4m long Lithium plasma of density up to 2 x 10{sup 14} e{sup {minus}}/cm{sup 3}. The initial beam density is greater than the plasma density, and the head of the bunch expels the plasma electrons leaving behind a uniform ion channel with transverse focusing fields of up to several thousand Tesla/m. The initial transverse beam size with sigma = 50--100 mu-m is larger than the matchedmore » size of 5 mu-m resulting in up to three beam envelope oscillations within the plasma. Time integrated optical transition radiation (OTR) is used to study the transverse beam profile immediately before and after the plasma to characterize the transverse beam dynamics as a function of plasma density. The head of the bunch deposits energy into plasma wakes, resulting in longitudinal accelerating fields which are witnessed by the tail of the same bunch. A time-resolved Cherenkov imaging system is located in an energy dispersive plane downstream of the plasma. It images the beam onto a streak camera allowing time-resolved measurements of the beam energy spectrum as a function of plasma density. Preliminary experimental data from the first three runs are compared to theory and computer simulations.« less
  • Full-scale particle-in-cell simulations of a meter-long plasma wakefield accelerator (PWFA) are presented in two dimensions. The results support the design of a current PWFA experiment in the nonlinear blowout regime where analytic solutions are intractable. A relativistic electron bunch excites a plasma wake that accelerates trailing particles at rates of several hundred MeV/m. A comparison is made of various simulation codes, and a parallel object-oriented code OSIRIS is used to model a full meter of acceleration. Excellent agreement is obtained between the simulations and analytic expressions for the transverse betatron oscillations of the beam. The simulations are used to developmore » scaling laws for designing future multi-GeV accelerator experiments. (c) 2000 The American Physical Society.« less
  • Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent throughmore » short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.« less