2005 APS March Meeting
Monday–Friday, March 21–25, 2005;
Los Angeles, CA
Session N5: Applications of THz Radiation
8:00 AM–11:00 AM,
Wednesday, March 23, 2005
LACC
Room: 502B
Sponsoring
Unit:
FIAP
Chair: Alan Todd, Advanced Energy Systems and Gwyn P. Williams, Jefferson Lab
Abstract ID: BAPS.2005.MAR.N5.1
Abstract: N5.00001 : Characteristics and Applications of High Intensity Coherent THz Pulses from Linear Accelerators*
8:00 AM–8:36 AM
Preview Abstract
Abstract
Author:
G. Lawrence Carr
(Brookhaven National Laboratory)
Fifteen years have passed since coherent synchrotron radiation (CSR) from
relativistic electrons was first observed[1,2]. Since then, CSR has served
as a tool for characterizing electron bunch shapes[3] and has been proposed
as a new type of millimeter wave source[4]. But until recently, the source
characteristics (spectral range reaching 1 THz, waveform shape, energy per
pulse, etc.) have not shown significant advantages over THz generators based
on ultra-fast lasers. The present generation of photo-injected linear
accelerators are now capable of producing sub-picosecond bunches with
approximately 1nC of charge (or more), and the coherent radiation they emit
has qualities that readily surpass what is available from other source
types[5]. This presentation will describe characteristics of the coherent
THz pulses produced as transition radiation from the Source Development Lab
linac[6] at the National Synchrotron Light Source. Consistent with
calculations, pulses can now be produced with energy approaching 100
microjoules (which is 2 orders of magnitude higher than from non-accelerator
methods) and with spectral content reaching 2 THz. Other facilities (e.g.,
at Jefferson Lab) operate at multi-MHz repetition rates such that the
average power is also very high. The E-field of a propagating THz pulse can
be coherently detected and imaged using the electro-optic effect in ZnTe[7].
When focused, the transient E-field for such a pulse can exceed 1 MV/cm and
should be sufficient for studying non-linear effects in solids, critical
currents in superconductors, and ultra-fast magnetization in thin films.
[1] T. Nakazato et al., \textit{Phys. Rev. Lett.} \textbf{63}, 1245 (1989).
[2] H. Happek et al., \textit{Phys. Rev. Lett.} \textbf{67}, 2962 (1991).
[3] R. Lai et al., \textit{Phys. Rev. }E\textbf{50}, R4294 (1994).
[4] T. Takahashi et al., \textit{Rev. Sci. Instrum}., \textbf{69}, 3770 (1998).
[5] G.L. Carr et al, \textit{Nature} \textbf{420}, 153 (2002).
[6] X.J. Wang and X.Y. Chang, \textit{Nucl. Instr. {\&} Meth}. A \textbf{507}, 310 (2003).
[7] Q. Wu et al., \textit{Appl. Phys. Lett.} \textbf{68}, 3224 (1996).
*In collaboration with H. Loos, B. Sheehy, D. Arena, J.B. Murphy, \& X.-J. Wang. Work supported by the U.S. Dept. of Energy under contract DE-AC02-98CH10886.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.N5.1