FEL2012 - List of Authors (Faatz, B.)

Paper

Title

Page

Status of the FLASH Facility

37

S. Schreiber, B. Faatz, J. Feldhaus, K. Honkavaara, R. Treusch, M. Vogt
DESY, Hamburg, Germany

FLASH at DESY, Hamburg is a soft X-ray free-electron laser user facility. After a 3.5 months shutdown in autumn 2011 required for civil construction for a second undulator beamline, beam operation started as scheduled in January 2012. FLASH shows again an improvement in performance with even higher single and average photon pulse energies, better stability, and significant improvements in operation procedures. The 4th user period started end of March 2012. A 4 months shutdown is scheduled early 2013 to connect the second undulator beamline to the FLASH accelerator.

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]

TUPD11

Optimization of HHG Seeding at Flash II

249

S. Ackermann, B. Faatz
DESY, Hamburg, Germany
V. Miltchev, J. Roßbach
Uni HH, Hamburg, Germany

FLASH* delivers coherent FEL radiation suitable for a variety of scientific purposes. In order to provide more beam time to the photon experiments, the FLASH II project, consisting of a second undulator branch and a new experimental Hall driven by the same superconducting modules as FLASH today has been started in 2008. While in the present undulator the kinetic energy of the electrons has to be changed in order to change the wavelength, the new beamline will benefit from variable gap undulators which will allow to have largely independent radiation wavelength; in the range of 10 to 40 nm an HHG seeding option is foreseen which will improve radiation quality for users beyond SASE. For experiments it is important to have the source point of the FEL radiation at the same position, close to the end of the undulator. However, one would like to keep the HHG focus at a fixed longitudinal position, such that wavelength changes will not require adjustments of the HHG focus. In this contribution, we will present the optimization of these conflicting requirements by opening undulator gaps at wavelength dependent positions, keeping both the seeding point and the source point for users fixed.
* The Free-Electron Laser in Hamburg

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.

TUPD33

Extraction Arc for FLASH II

305

M. Scholz, W. Decking, B. Faatz, T. Limberg
DESY, Hamburg, Germany

FLASH II is an extension of FLASH, an FEL user facility at DESY, Hamburg. It uses the same linear accelerator. A fast kicker and a septum will be installed behind the last superconducting acceleration module at the FLASH linac, providing the possibility to distribute beam to the FLASH undulator beamline and through the new extraction arc into the beamline FLASH2. It is foreseen that at the end of the FLASH II extraction arc the beam can be send into two separate beamlines: The main beamline hosting undulators for SASE and space for HHG seeding, the other might serve later another beamline. The FLASH2 extraction arc was designed to mitigate the effects from coherent synchrotron radiation (CSR) like emittance and energy spread growth. The extraction arc for FLASH2 places also demands on the existing FLASH beamline which are taken into account. The lattice optimization of the arc was done using the program ELEGANT. Start to end simulations for different bunch charges including FEL simulations with GENESIS were carried out to show the feasibility of the FLASH2 extraction arc design.

WEPD07

Status of the FLASH II Project

381

K. Honkavaara, S. Ackermann, V. Ayvazyan, N. Baboi, V. Balandin, W. Decking, S. Düsterer, H.-J. Eckoldt, B. Faatz, M. Felber, J. Feldhaus, N. Golubeva, M. Körfer, M. Kuhlmann, T. Laarmann, A. Leuschner, L. Lilje, T. Limberg, N. Mildner, D. Nölle, F. Obier, A. Petrov, E. Plönjes, K. Rehlich, H. Remde, H. Schlarb, B. Schmidt, M. Schmitz, M. Scholz, S. Schreiber, H. Schulte-Schrepping, J. Spengler, M. Staack, N. Stojanovic, K.I. Tiedtke, M. Tischer, R. Treusch, M. Vogt, H.C. Weddig, T. Wohlenberg
DESY, Hamburg, Germany
M. Drescher, A. Hage, V. Miltchev, R. Riedel, J. Rönsch-Schulenburg, J. Roßbach, M. Schulz, A. Willner
Uni HH, Hamburg, Germany
F. Tavella
HIJ, Jena, Germany

The extension of the FLASH facility at DESY (Hamburg, Germany) - FLASH II Project - is under way. The extension includes a second undulator line with variable gap undulators to allow a more flexible operation, and a new experimental hall for photon experiments. The present FLASH linac will drive the both undulator beamlines. Civil construction of the new buildings has been started in autumn 2011 continuing in several steps until early 2013. The design of the new beamline including the extraction from the FLASH linac and the undulator is mostly finished, and the manufacturing of the components is under way. The mounting of the beamline will start in autumn 2012, and the commissioning with beam is scheduled for second half of 2013. We report here the design of the different phases of the project including the time schedule up to the first user operation.

Paper	Title	Page
MOPD01	Status of the FLASH Facility	37
	S. Schreiber, B. Faatz, J. Feldhaus, K. Honkavaara, R. Treusch, M. Vogt DESY, Hamburg, Germany
	FLASH at DESY, Hamburg is a soft X-ray free-electron laser user facility. After a 3.5 months shutdown in autumn 2011 required for civil construction for a second undulator beamline, beam operation started as scheduled in January 2012. FLASH shows again an improvement in performance with even higher single and average photon pulse energies, better stability, and significant improvements in operation procedures. The 4th user period started end of March 2012. A 4 months shutdown is scheduled early 2013 to connect the second undulator beamline to the FLASH accelerator.

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]

TUPD11	Optimization of HHG Seeding at Flash II	249
	S. Ackermann, B. Faatz DESY, Hamburg, Germany V. Miltchev, J. Roßbach Uni HH, Hamburg, Germany
	FLASH* delivers coherent FEL radiation suitable for a variety of scientific purposes. In order to provide more beam time to the photon experiments, the FLASH II project, consisting of a second undulator branch and a new experimental Hall driven by the same superconducting modules as FLASH today has been started in 2008. While in the present undulator the kinetic energy of the electrons has to be changed in order to change the wavelength, the new beamline will benefit from variable gap undulators which will allow to have largely independent radiation wavelength; in the range of 10 to 40 nm an HHG seeding option is foreseen which will improve radiation quality for users beyond SASE. For experiments it is important to have the source point of the FEL radiation at the same position, close to the end of the undulator. However, one would like to keep the HHG focus at a fixed longitudinal position, such that wavelength changes will not require adjustments of the HHG focus. In this contribution, we will present the optimization of these conflicting requirements by opening undulator gaps at wavelength dependent positions, keeping both the seeding point and the source point for users fixed. * The Free-Electron Laser in Hamburg

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.

TUPD33	Extraction Arc for FLASH II	305
	M. Scholz, W. Decking, B. Faatz, T. Limberg DESY, Hamburg, Germany
	FLASH II is an extension of FLASH, an FEL user facility at DESY, Hamburg. It uses the same linear accelerator. A fast kicker and a septum will be installed behind the last superconducting acceleration module at the FLASH linac, providing the possibility to distribute beam to the FLASH undulator beamline and through the new extraction arc into the beamline FLASH2. It is foreseen that at the end of the FLASH II extraction arc the beam can be send into two separate beamlines: The main beamline hosting undulators for SASE and space for HHG seeding, the other might serve later another beamline. The FLASH2 extraction arc was designed to mitigate the effects from coherent synchrotron radiation (CSR) like emittance and energy spread growth. The extraction arc for FLASH2 places also demands on the existing FLASH beamline which are taken into account. The lattice optimization of the arc was done using the program ELEGANT. Start to end simulations for different bunch charges including FEL simulations with GENESIS were carried out to show the feasibility of the FLASH2 extraction arc design.

WEPD07	Status of the FLASH II Project	381
	K. Honkavaara, S. Ackermann, V. Ayvazyan, N. Baboi, V. Balandin, W. Decking, S. Düsterer, H.-J. Eckoldt, B. Faatz, M. Felber, J. Feldhaus, N. Golubeva, M. Körfer, M. Kuhlmann, T. Laarmann, A. Leuschner, L. Lilje, T. Limberg, N. Mildner, D. Nölle, F. Obier, A. Petrov, E. Plönjes, K. Rehlich, H. Remde, H. Schlarb, B. Schmidt, M. Schmitz, M. Scholz, S. Schreiber, H. Schulte-Schrepping, J. Spengler, M. Staack, N. Stojanovic, K.I. Tiedtke, M. Tischer, R. Treusch, M. Vogt, H.C. Weddig, T. Wohlenberg DESY, Hamburg, Germany M. Drescher, A. Hage, V. Miltchev, R. Riedel, J. Rönsch-Schulenburg, J. Roßbach, M. Schulz, A. Willner Uni HH, Hamburg, Germany F. Tavella HIJ, Jena, Germany
	The extension of the FLASH facility at DESY (Hamburg, Germany) - FLASH II Project - is under way. The extension includes a second undulator line with variable gap undulators to allow a more flexible operation, and a new experimental hall for photon experiments. The present FLASH linac will drive the both undulator beamlines. Civil construction of the new buildings has been started in autumn 2011 continuing in several steps until early 2013. The design of the new beamline including the extraction from the FLASH linac and the undulator is mostly finished, and the manufacturing of the components is under way. The mounting of the beamline will start in autumn 2012, and the commissioning with beam is scheduled for second half of 2013. We report here the design of the different phases of the project including the time schedule up to the first user operation.