FEL2012 - List of Authors (Hass, E.)

Paper

Title

Page

First Direct Seeding at 38nm

197

C. Lechner, A. Azima, J. Bödewadt, M. Drescher, E. Hass, U. Hipp, Th. Maltezopoulos, V. Miltchev, M. Rehders, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian, M. Wieland
Uni HH, Hamburg, Germany
S. Ackermann, S. Bajt, H. Dachraoui, H. Delsim-Hashemi, S. Düsterer, B. Faatz, K. Honkavaara, T. Laarmann, M. Mittenzwey, H. Schlarb, S. Schreiber, L. Schroedter, M. Tischer
DESY, Hamburg, Germany
F. Curbis
MAX-lab, Lund, Sweden
R. Ischebeck
PSI, Villigen PSI, Switzerland
S. Khan
DELTA, Dortmund, Germany
V. Wacker
University of Hamburg, Hamburg, Germany

Funding: The project is supported by the Federal Ministry of Education and Research of Germany under contract No. 05 K10GU1 and by the German Research Foundation programme graduate school 1355.
The sFLASH project at DESY is an experiment to study direct seeding using a source based on the high-harmonic generation (HHG) process. In contrast to SASE, a seeded FEL exhibits greatly improved longitudinal coherence and higher shot-to-shot stability (both spectral and energetic). In addition, the output of the seeded FEL is intrinsically synchronized to the HHG drive laser, thus enabling pump-probe experiments with a resolution of the order of 10 fs. The installation and successful commissioning of the sFLASH components in 2010/2011 has been followed by a planned upgrade in autumn 2011. As a result of these improvements, in spring 2012 direct HHG seeding at 38 nm has been successfully demonstrated. In this contribution, we describe the experimental layout and announce the first seeding at 38 nm.

Slides TUOAI01 [11.553 MB]

TUPD32

Simultaneous Operation of a Multi Beamline FEL Facility

301

B. Faatz, S. Ackermann, V. Ayvazyan, W. Decking, C. Grün, K. Klose, F. Obier, S. Pfeiffer, M. Scholz, J. Wortmann
DESY, Hamburg, Germany
E. Hass
Uni HH, Hamburg, Germany

The FLASH II project will add an undulator beamline and a new experimental Hall to the existing FLASH Facility. In addition to improving the radiation properties of the FEL by using seeding, one of the main goals is to double the beamtime of the facility for users. At the moment, we deliver photon pulses in 10 Hz bursts with up to 800 bunches within each RF pulse. In order not to limit parameter ranges, we will have to give those same tuning possibilities within an RF pulse for each of the users independently. For this purpose, several tests have been performed to determine the limits of the difference in beam parameters which can be delivered. We will show to what extend we can switch fast between two beamlines, how we can change photon pulse length by allowing different charges, have different energy in the two beamlines simultaneously to allow for wavelength scans for the fixed-gap undulator presently built in FLASH, while not interfering with user operation of the new beamline.

THPD33

Generation of Ultra-short Electron Bunches at FLASH

610

J. Rönsch-Schulenburg, E. Hass, A. Kuhl, T. Plath, M. Rehders, J. Roßbach
Uni HH, Hamburg, Germany
A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
N. Baboi, M. Bousonville, M.K. Czwalinna, C. Gerth, K. Klose, T. Limberg, U. Mavrič, H. Schlarb, B. Schmidt, S. Schreiber, B. Steffen, C. Sydlo, S. Vilcins, S. Wesch
DESY, Hamburg, Germany
S. Schnepp, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: The work is supported by German Federal Ministry of Education and Research (BMBF) within Joint Project - FSP 301 under the contract number 05K10GU2.
In order to produce radiation pulses of a few femtoseconds at FELs like FLASH, different concepts have been proposed. Probably the most robust method is to create an electron bunch, which is in the most extreme case as short as one longitudinal optical mode. For FLASH this translates into a bunch length of a few micrometers only. In order to mitigate space charge effects, the bunch charge needs to be about 20 pC. The technical requirements to achieve this goal are discussed. This includes beam dynamics studies to optimize the injection and compression of small charge electron bunches. A reduced photo injector laser pulse duration helps to relax the RF tolerance which scales linear with the compression factor. A new photo injector laser with sub-picosecond pulse duration in combination with a stretcher is used to optimize the initial bunch length. The commissioning of the new laser system and first experiments are described. Limitations of the presently available electron beam diagnostics at FLASH for short, low charge bunches are analyzed. Improvements of the longitudinal phase space diagnostics and the commissioning of a more sensitive beam arrival time monitor are described.

Paper	Title	Page
TUOAI01	First Direct Seeding at 38nm	197
	C. Lechner, A. Azima, J. Bödewadt, M. Drescher, E. Hass, U. Hipp, Th. Maltezopoulos, V. Miltchev, M. Rehders, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian, M. Wieland Uni HH, Hamburg, Germany S. Ackermann, S. Bajt, H. Dachraoui, H. Delsim-Hashemi, S. Düsterer, B. Faatz, K. Honkavaara, T. Laarmann, M. Mittenzwey, H. Schlarb, S. Schreiber, L. Schroedter, M. Tischer DESY, Hamburg, Germany F. Curbis MAX-lab, Lund, Sweden R. Ischebeck PSI, Villigen PSI, Switzerland S. Khan DELTA, Dortmund, Germany V. Wacker University of Hamburg, Hamburg, Germany
	Funding: The project is supported by the Federal Ministry of Education and Research of Germany under contract No. 05 K10GU1 and by the German Research Foundation programme graduate school 1355. The sFLASH project at DESY is an experiment to study direct seeding using a source based on the high-harmonic generation (HHG) process. In contrast to SASE, a seeded FEL exhibits greatly improved longitudinal coherence and higher shot-to-shot stability (both spectral and energetic). In addition, the output of the seeded FEL is intrinsically synchronized to the HHG drive laser, thus enabling pump-probe experiments with a resolution of the order of 10 fs. The installation and successful commissioning of the sFLASH components in 2010/2011 has been followed by a planned upgrade in autumn 2011. As a result of these improvements, in spring 2012 direct HHG seeding at 38 nm has been successfully demonstrated. In this contribution, we describe the experimental layout and announce the first seeding at 38 nm.
	Slides TUOAI01 [11.553 MB]

TUPD32	Simultaneous Operation of a Multi Beamline FEL Facility	301
	B. Faatz, S. Ackermann, V. Ayvazyan, W. Decking, C. Grün, K. Klose, F. Obier, S. Pfeiffer, M. Scholz, J. Wortmann DESY, Hamburg, Germany E. Hass Uni HH, Hamburg, Germany
	The FLASH II project will add an undulator beamline and a new experimental Hall to the existing FLASH Facility. In addition to improving the radiation properties of the FEL by using seeding, one of the main goals is to double the beamtime of the facility for users. At the moment, we deliver photon pulses in 10 Hz bursts with up to 800 bunches within each RF pulse. In order not to limit parameter ranges, we will have to give those same tuning possibilities within an RF pulse for each of the users independently. For this purpose, several tests have been performed to determine the limits of the difference in beam parameters which can be delivered. We will show to what extend we can switch fast between two beamlines, how we can change photon pulse length by allowing different charges, have different energy in the two beamlines simultaneously to allow for wavelength scans for the fixed-gap undulator presently built in FLASH, while not interfering with user operation of the new beamline.

THPD33	Generation of Ultra-short Electron Bunches at FLASH	610
	J. Rönsch-Schulenburg, E. Hass, A. Kuhl, T. Plath, M. Rehders, J. Roßbach Uni HH, Hamburg, Germany A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany N. Baboi, M. Bousonville, M.K. Czwalinna, C. Gerth, K. Klose, T. Limberg, U. Mavrič, H. Schlarb, B. Schmidt, S. Schreiber, B. Steffen, C. Sydlo, S. Vilcins, S. Wesch DESY, Hamburg, Germany S. Schnepp, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: The work is supported by German Federal Ministry of Education and Research (BMBF) within Joint Project - FSP 301 under the contract number 05K10GU2. In order to produce radiation pulses of a few femtoseconds at FELs like FLASH, different concepts have been proposed. Probably the most robust method is to create an electron bunch, which is in the most extreme case as short as one longitudinal optical mode. For FLASH this translates into a bunch length of a few micrometers only. In order to mitigate space charge effects, the bunch charge needs to be about 20 pC. The technical requirements to achieve this goal are discussed. This includes beam dynamics studies to optimize the injection and compression of small charge electron bunches. A reduced photo injector laser pulse duration helps to relax the RF tolerance which scales linear with the compression factor. A new photo injector laser with sub-picosecond pulse duration in combination with a stretcher is used to optimize the initial bunch length. The commissioning of the new laser system and first experiments are described. Limitations of the presently available electron beam diagnostics at FLASH for short, low charge bunches are analyzed. Improvements of the longitudinal phase space diagnostics and the commissioning of a more sensitive beam arrival time monitor are described.