| Paper |
Title |
Page |
| IT12 |
Investigations of Longitudinal Charge Distribution in Very Short Electron-Bunches
|
56 |
| |
- M. Hüning
RWTH-Aachen, III. Physik Institut, Aachen, Germany
|
|
| |
Electro-optical-sampling is a powerful technique to measure
the longitudinal charge distribution of very short electron
bunches. The electrical field moving with the bunch
induces an optical an-isotropy in a ZnTe crystal which is
probed by a polarized laser pulse. Two measurement principles
are possible. In the first one a short laser pulse of
lengths <50 fs is used directly to scan the time varying
optical properties of the crystal. In the second method the
laser pulse is frequency chirped and the temporal information
is encoded into the time ordered frequency spectrum,
which can be recovered by an optical grating and a CCD
camera.
A resolution in the 100 fs regime can also be achieved
with longitudinal phase space tomography. Acceleration
on the slope of the rf wave at different phases and measurements
of the energy profiles are sufficient for a reconstruction
algorithm based on maximum entropy methods.
The longitudinal phase space distribution can be obtained
without artifacts due to the limited angular range of the
projections.
|
|