Author: Tanikawa, T.
Paper Title Page
Seeding Preparation at the FLASH2 Beamline  
  • T. Tanikawa, A. Hage
    DESY, Hamburg, Germany
  At the FLASH Facility at DESY, Hamburg, a new undulator line, referred to as FLASH2, has been added. First electron beam in FLASH2 has reached the beam dump in May. Further commissioning, including first SASE, is foreseen for the remainder of the year. This FEL has been designed to include seeding in the future, such as a high-gain harmonic generation (HGHG) or an echo-enable harmonic generation (EEHG). The optimal choice for seeding at FLASH2 is under discussion. For seeding at FLASH2, an XUV spectrometer, a laser system based on optical parametric chirped-pulse amplification (OPCPA) as well as a system for a third harmonic generation (THG) including diagnostic tools have been prepared. We will report the current status.  
Overview of FEL Seeding Activities at FLASH  
  • J. Bödewadt, S. Ackermann, R.W. Aßmann, N. Ekanayake, B. Faatz, G. Feng, I. Hartl, R. Ivanov, T. Laarmann, J.M. Mueller, T. Tanikawa
    DESY, Hamburg, Germany
  • S. Ackermann, A. Azima, M. Drescher, L.L. Lazzarino, C. Lechner, Th. Maltezopoulos, V. Miltchev, T. Plath, J. Roßbach
    Uni HH, Hamburg, Germany
  • K.E. Hacker, S. Khan, R. Molo
    DELTA, Dortmund, Germany
  The free-electron laser facility FLASH at DESY operates since several years in SASE mode, delivering high-intensity FEL pulses in the extreme ultra violet and soft x-ray wavelength range for users. In order to get more control of the characteristics of the FEL pulses external FEL seeding has proven to be a reliable method to do so. At FLASH, an experimental setup to test several different external seeding methods has been installed since 2010. After successful demonstration of direct seeding at 38 nm, the setup is now being commissioned to operate in HGHG and EEHG mode. Furthermore, other studies on laser induced effects on the electron beam dynamics will be performed. Beside the experimental activities, a design for the seeding option for the FLASH2 beamline is currently under investigation. The goal for that is to develop a concept which is compatible with the operation of FLASH1 and which satisfies the high demands of the future user community. In this contribution, we give an overview of the activities on FEL seeding at FLASH.