FEL2014 - List of Keywords (flattop)

Paper	Title	Other Keywords	Page
THP006	Optimization of the PITZ Photo Injector Towards the Best Achievable Beam Quality	laser, emittance, electron, cathode	685
	M. Khojoyan, M. Krasilnikov, F. Stephan, G. Vashchenko DESY Zeuthen, Zeuthen, Germany
	Funding: The work is supported by the German Federal Ministry of education and Research, project 05K10CHE and RFBR grant 13-02-91323. Uniform 3D ellipsoids are proven to be the best distributions for high brightness charged particle beam applications due to the linear dependence of the space charge fields on the position within the distribution. Such electron bunches have lower emittance and are less sensitive to the machine settings and, therefore, should allow more reliable operation, which is one of the key requirements for single-pass free-electron lasers (FELs). The Photo Injector test facility at DESY, Zeuthen site (PITZ) is optimizing high brightness electron sources for linac based FELs such as the European XFEL. Recent measurements at PITZ using a photocathode laser with a flat-top temporal profile have revealed record low transverse emittance values at different bunch charges. As a next step towards the further improvement of the high quality beams, a cathode laser system, capable of producing quasi-3D ellipsoidal bunches is intended to be used at PITZ. In this work the beam dynamics optimization results for various bunch charges and for flat-top and 3D ellipsoidal cathode laser shapes are presented. For each working point the relative emittance growth is estimated due to possible deviations of the machine parameters.

THP044	RF Pulse Flattening in the SwissFEL Test Facility based on Model-free Iterative Learning Control	controls, klystron, electron, feedback	824
	A. Řežaeizadeh, R. Smith Automatic Control Laboratory, ETH Zurich, Zurich, Switzerland A. Řežaeizadeh, T. Schilcher PSI, Villigen PSI, Switzerland
	Funding: Paul Scherrer Institut This paper introduces an iterative approach to producing flat-topped radio frequency (RF) pulses for driving the pulsed linear accelerators in the Swiss free electron laser (SwissFEL). The method is based on model-free iterative learning control which iteratively updates the input pulse shape in order to generate the desired amplitude and phase pulses at the output of the RF system. The method has been successfully applied to the klystron output to improve the flatness of the amplitude and phase pulse profiles. * P. Janssens,et.al, "Model-free iterative learning control for LTI systems …", 18th IFAC. <CR> ** N. Amann, et.al , "ILC for discrete-time systems …", IEE Control Theory Apps.

Paper

Title

Other Keywords

Page

THP006

Optimization of the PITZ Photo Injector Towards the Best Achievable Beam Quality

laser, emittance, electron, cathode

685

M. Khojoyan, M. Krasilnikov, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany

Funding: The work is supported by the German Federal Ministry of education and Research, project 05K10CHE and RFBR grant 13-02-91323.
Uniform 3D ellipsoids are proven to be the best distributions for high brightness charged particle beam applications due to the linear dependence of the space charge fields on the position within the distribution. Such electron bunches have lower emittance and are less sensitive to the machine settings and, therefore, should allow more reliable operation, which is one of the key requirements for single-pass free-electron lasers (FELs). The Photo Injector test facility at DESY, Zeuthen site (PITZ) is optimizing high brightness electron sources for linac based FELs such as the European XFEL. Recent measurements at PITZ using a photocathode laser with a flat-top temporal profile have revealed record low transverse emittance values at different bunch charges. As a next step towards the further improvement of the high quality beams, a cathode laser system, capable of producing quasi-3D ellipsoidal bunches is intended to be used at PITZ. In this work the beam dynamics optimization results for various bunch charges and for flat-top and 3D ellipsoidal cathode laser shapes are presented. For each working point the relative emittance growth is estimated due to possible deviations of the machine parameters.

THP044

RF Pulse Flattening in the SwissFEL Test Facility based on Model-free Iterative Learning Control

controls, klystron, electron, feedback

824

A. Řežaeizadeh, R. Smith
Automatic Control Laboratory, ETH Zurich, Zurich, Switzerland
A. Řežaeizadeh, T. Schilcher
PSI, Villigen PSI, Switzerland

Funding: Paul Scherrer Institut
This paper introduces an iterative approach to producing flat-topped radio frequency (RF) pulses for driving the pulsed linear accelerators in the Swiss free electron laser (SwissFEL). The method is based on model-free iterative learning control which iteratively updates the input pulse shape in order to generate the desired amplitude and phase pulses at the output of the RF system. The method has been successfully applied to the klystron output to improve the flatness of the amplitude and phase pulse profiles.
* P. Janssens,et.al, "Model-free iterative learning control for LTI systems …", 18th IFAC. <CR>
** N. Amann, et.al , "ILC for discrete-time systems …", IEE Control Theory Apps.