FEL2011 - List of Authors (Prat, E.)

Paper	Title	Page
TUPA18	Considerations about Optics-Based Phase-Space Measurements at Linac-Based FEL Facilities	231
	B. Beutner, E. Prat Paul Scherrer Institut, Villigen, Switzerland
	Transverse phase-space measurements are an essential issue for FEL facilities. After acceleration in the injector the energy is sufficiently high to bring the beam out of the space-charge dominated regime, thus optics based techniques are favored. The beam moments at a given point in the machine are fitted to beam size values downstream with different phase advances between the reconstruction and the measurement point. Two principle methods are possible. Beam sizes can be measured at different positions in the beam line keeping the lattice unchanged. The other possibility is to actively change quadrupoles and use only one screen. These two techniques are compared in this paper including monte-carlo studies on systematic errors using the SwissFEL Injector Test Facility as an example. On the other hand beam size measurements, which are done with OTR screens at SwissFEL Injector Test Facility, are critical for such measurements. An analysis of these images can be an issue, especially if the signal-to-noise is compromised for example by low bunch charges. This study on the phase-space measurement techniques will be completed by a discussion of the image post-processing procedures.

TUPA25	EEHG Seeding Design for SwissFEL	251
	E. Prat, S. Reiche Paul Scherrer Institut, Villigen, Switzerland
	The SwissFEL facility, planned at the Paul Scherrer Institute, is based on the SASE operation of a hard (1-7 Å) and a soft (7-70 Å) X-ray FEL beamline. In addition, seeding is foreseen for the soft X-ray beamline, down to a wavelength of 1 nm. The Echo-Enabled Harmonic Generation (EEHG) scheme, which utilizes a rather complex manipulation of the longitudinal phase space distribution of the electron beam to generate high harmonic density modulation, is presently considered the first choice for seeding at SwissFEL. However, EEHG is highly demanding and complex at 1 nm, therefore other strategies like High-Harmonic Generation (HHG) and self-seeding are also evaluated. This paper presents the current status of the seeding design for SwissFEL based on EEHG.

THPB30	SwissFEL Injector Test Facility – Test and Plans	625
	M. Pedrozzi, M. Aiba, S. Bettoni, B. Beutner, A. Falone, R. Ganter, R. Ischebeck, F. Le Pimpec, G.L. Orlandi, E. Prat, S. Reiche, T. Schietinger, A. Trisorio, C. Vicario Paul Scherrer Institut, Villigen, Switzerland
	In August 2010 the Paul Scherrer Institute inaugurated the SwissFEL Injector test facility as a first step toward the Swiss hard X-ray FEL planned at PSI. The main purpose of the facility is to demonstrate and consolidate the generation of high-brightness beam as required to drive the 6 GeV SwissFEL accelerator. Additionally the injector serves as a platform supporting development and test of accelerator components/systems and optimization procedures foreseen for SwissFEL. In this paper we report on the present status of the commissioning with some emphasis on emittance measurements and component performances. The scientific program and long-term plans will be discussed as well.

Paper

Title

Page

Considerations about Optics-Based Phase-Space Measurements at Linac-Based FEL Facilities

231

B. Beutner, E. Prat
Paul Scherrer Institut, Villigen, Switzerland

Transverse phase-space measurements are an essential issue for FEL facilities. After acceleration in the injector the energy is sufficiently high to bring the beam out of the space-charge dominated regime, thus optics based techniques are favored. The beam moments at a given point in the machine are fitted to beam size values downstream with different phase advances between the reconstruction and the measurement point. Two principle methods are possible. Beam sizes can be measured at different positions in the beam line keeping the lattice unchanged. The other possibility is to actively change quadrupoles and use only one screen. These two techniques are compared in this paper including monte-carlo studies on systematic errors using the SwissFEL Injector Test Facility as an example. On the other hand beam size measurements, which are done with OTR screens at SwissFEL Injector Test Facility, are critical for such measurements. An analysis of these images can be an issue, especially if the signal-to-noise is compromised for example by low bunch charges. This study on the phase-space measurement techniques will be completed by a discussion of the image post-processing procedures.

TUPA25

EEHG Seeding Design for SwissFEL

251

E. Prat, S. Reiche
Paul Scherrer Institut, Villigen, Switzerland

The SwissFEL facility, planned at the Paul Scherrer Institute, is based on the SASE operation of a hard (1-7 Å) and a soft (7-70 Å) X-ray FEL beamline. In addition, seeding is foreseen for the soft X-ray beamline, down to a wavelength of 1 nm. The Echo-Enabled Harmonic Generation (EEHG) scheme, which utilizes a rather complex manipulation of the longitudinal phase space distribution of the electron beam to generate high harmonic density modulation, is presently considered the first choice for seeding at SwissFEL. However, EEHG is highly demanding and complex at 1 nm, therefore other strategies like High-Harmonic Generation (HHG) and self-seeding are also evaluated. This paper presents the current status of the seeding design for SwissFEL based on EEHG.

THPB30

SwissFEL Injector Test Facility – Test and Plans

625

M. Pedrozzi, M. Aiba, S. Bettoni, B. Beutner, A. Falone, R. Ganter, R. Ischebeck, F. Le Pimpec, G.L. Orlandi, E. Prat, S. Reiche, T. Schietinger, A. Trisorio, C. Vicario
Paul Scherrer Institut, Villigen, Switzerland

In August 2010 the Paul Scherrer Institute inaugurated the SwissFEL Injector test facility as a first step toward the Swiss hard X-ray FEL planned at PSI. The main purpose of the facility is to demonstrate and consolidate the generation of high-brightness beam as required to drive the 6 GeV SwissFEL accelerator. Additionally the injector serves as a platform supporting development and test of accelerator components/systems and optimization procedures foreseen for SwissFEL. In this paper we report on the present status of the commissioning with some emphasis on emittance measurements and component performances. The scientific program and long-term plans will be discussed as well.