FEL2014 - List of Authors (Frei, F.)

Paper

Title

Page

Experimental Results of Diagnostics Response for Longitudinal Phase Space

657

F. Frei, V.R. Arsov, H. Brands, R. Ischebeck, B. Kalantari, R. Kalt, B. Keil, W. Koprek, F. Löhl, G.L. Orlandi, Á. Saá Hernández, T. Schilcher, V. Schlott
PSI, Villigen PSI, Switzerland

At SwissFEL, electron bunches will be accelerated, shaped, and longitudinally compressed by different radio frequency (RF) structures (S-, C-, and X-band) in combination with magnetic chicanes. In order to meet the envisaged performance, it is planned to regulate the different RF parameters based on the signals from numerous electron beam diagnostics. Here we will present experimental results of the diagnostics response on RF phase and field amplitude variations that were obtained at the SwissFEL Injector Test Facility.

Slides THB02 [6.110 MB]

THP085

Commissioning and Results from the Bunch Arrival-time Monitor Downstream the Bunch Compressor at the SwissFEL Test Injector

933

V.R. Arsov, M. Aiba, M.M. Dehler, F. Frei, S. Hunziker, M.G. Kaiser, A. Romann, V. Schlott
PSI, Villigen PSI, Switzerland

A high bandwidth Bunch Arrival-Time Monitor has been commissioned at the Swiss FEL test injector. A new acquisition front end allowing utilization of the ADC full dynamic range has been implemented. The resolution is measured as a function of the charge for different EOM front-ends. Downstream the magnetic chicane the bunch arrival time is sensitive to the amplitude and phases of the RF structures, responsible for creation of an energy chirp, used for bunch compression, as well as the ones of the harmonic cavity, used for phase space linearization. The time of flight as a function of the angle of the magnetic chicane has also been measured.

THP097

Longitudinal Response Matrix Simulations for the SwissFEL Injector Test Facility

964

Á. Saá Hernández, F. Frei, R. Ischebeck
PSI, Villigen PSI, Switzerland
B. Beutner
DESY, Hamburg, Germany

The Singular Value Decomposition (SVD) method has been applied to the SwissFEL Injector Test Facility to identify and better expose the various relationships among the possible jitter sources affecting the longitudinal phase space distribution and the longitudinal diagnostic elements that measure them. To this end, several longitudinal tracking simulations have been run using the Litrack code. In these simulations the RF and laser jitter sources are varied one-by-one within a range spanning twice their expected stability. The particle distributions have been dumped at the diagnostic locations and the measured quantities analyzed. A matrix has been built by linearly fitting the response of each measured quantity to each jitter source. This response matrix is normalized to the jitter source stability and the instrumentation accuracy, and it is inverted and analyzed using SVD. From the eigenvalues and eigenvectors the sensitivity of the diagnostics to the jitters can be evaluated and their specifications and locations optimized.

Paper	Title	Page
THB02	Experimental Results of Diagnostics Response for Longitudinal Phase Space	657
	F. Frei, V.R. Arsov, H. Brands, R. Ischebeck, B. Kalantari, R. Kalt, B. Keil, W. Koprek, F. Löhl, G.L. Orlandi, Á. Saá Hernández, T. Schilcher, V. Schlott PSI, Villigen PSI, Switzerland
	At SwissFEL, electron bunches will be accelerated, shaped, and longitudinally compressed by different radio frequency (RF) structures (S-, C-, and X-band) in combination with magnetic chicanes. In order to meet the envisaged performance, it is planned to regulate the different RF parameters based on the signals from numerous electron beam diagnostics. Here we will present experimental results of the diagnostics response on RF phase and field amplitude variations that were obtained at the SwissFEL Injector Test Facility.
	Slides THB02 [6.110 MB]

THP085	Commissioning and Results from the Bunch Arrival-time Monitor Downstream the Bunch Compressor at the SwissFEL Test Injector	933
	V.R. Arsov, M. Aiba, M.M. Dehler, F. Frei, S. Hunziker, M.G. Kaiser, A. Romann, V. Schlott PSI, Villigen PSI, Switzerland
	A high bandwidth Bunch Arrival-Time Monitor has been commissioned at the Swiss FEL test injector. A new acquisition front end allowing utilization of the ADC full dynamic range has been implemented. The resolution is measured as a function of the charge for different EOM front-ends. Downstream the magnetic chicane the bunch arrival time is sensitive to the amplitude and phases of the RF structures, responsible for creation of an energy chirp, used for bunch compression, as well as the ones of the harmonic cavity, used for phase space linearization. The time of flight as a function of the angle of the magnetic chicane has also been measured.

THP097	Longitudinal Response Matrix Simulations for the SwissFEL Injector Test Facility	964
	Á. Saá Hernández, F. Frei, R. Ischebeck PSI, Villigen PSI, Switzerland B. Beutner DESY, Hamburg, Germany
	The Singular Value Decomposition (SVD) method has been applied to the SwissFEL Injector Test Facility to identify and better expose the various relationships among the possible jitter sources affecting the longitudinal phase space distribution and the longitudinal diagnostic elements that measure them. To this end, several longitudinal tracking simulations have been run using the Litrack code. In these simulations the RF and laser jitter sources are varied one-by-one within a range spanning twice their expected stability. The particle distributions have been dumped at the diagnostic locations and the measured quantities analyzed. A matrix has been built by linearly fitting the response of each measured quantity to each jitter source. This response matrix is normalized to the jitter source stability and the instrumentation accuracy, and it is inverted and analyzed using SVD. From the eigenvalues and eigenvectors the sensitivity of the diagnostics to the jitters can be evaluated and their specifications and locations optimized.