25th Anniversary of the First Lasing at TTF (now FLASH) – International Symposium

17 Nov 2025, 13:00 → 18 Nov 2025, 15:00 Europe/Berlin

Auditorium (DESY)

Dear Colleagues and Friends of FLASH and DESY,

 

This year we celebrate a remarkable milestone: the 25^th anniversary of the first lasing at the TESLA Test Facility (TTF) – today known as FLASH. This breakthrough laid the foundation for the worldwide development of outstanding FEL user facilities.

 

To mark this pioneering achievement, DESY is delighted to invite you to a two-day international scientific symposium on 17–18 November 2025.

 

The programme will include historical retrospectives, reviews of major technological advances, scientific highlights, a dedicated PhD session, and ample opportunities to meet and reconnect with colleagues and companions.

 

We warmly welcome you to join us in celebrating 25 years of lasing at TTF/FLASH. Please register via the form provided on this Indico page.

 

We look forward to seeing you in Hamburg!

Monday 17 November

Introduction and Historical Context

1 Welcome

Speaker: Beate Heinemann

2 Introduction, Context and Perspective

Speaker: Wim Leemans & Britta Redlich

3 FLASH - a 'historical' perspective

Speaker: Joerg Rossbach

4 Topic TBC: SASE FEL Strategies and Politics

Speaker: Gerd Materlik

5 Topic TBC: Diffraction before Destruction - X-ray diffraction on a single molecule

Speaker: Henry Chapman

14:40 Coffee break

Key Technologies

6 TTF FEL: Lessons Learned from the First Lasing to Saturation

Speaker: Mikhail Yurkov

7 Development of High-Brightness Photoinjectors for FLASH and European XFEL

Speaker: Frank Stephan

8 Superconducting RF Linacs and FELs - a Successful Partnership

Speaker: Hans Weise

9 Challenges in Numerical FEL Simulations

Speaker: Sven Reiche

10 Advanced Photon Diagnostics and beamlines for (X)FELs

Speaker: Kai Tiedtke

17:15 Coffee break

PhD Session

Selected short presentations from the almost 100 FLASH-related PhD theses

18:45 Dinner

Tuesday 18 November

Photon Science Highlights

11 From FLASH to the Stars - Photochemistry of Polycyclic Aromatic Hydrocarbons

Speaker: Melanie Schnell

12 Topic TBC: Explosion Dynamics of Clusters

Speaker: Taisia Gorkhover

13 Topic TBC: Single-Shot THz-Field-Driven X-Ray Streak Camera

Speaker: Ulrike Fruehling

Video greetings: Video-greetings from around the world

10:35 Coffee break

Future Perspectives

14 From FLASH to European XFEL

Speaker: Thomas Tschentscher

15 Topic TBC: Seeded FELS

Speaker: Luca Giannessi

16 High Repetition-Rate FELs: Technical Advances and Scientific Prospects

Speaker: Zhentang Zhao

17 Topic TBC: FLASH2020+

Speaker: Lucas Schaper

12:45 Lunch Break

Photon Science Highlights

18 Topic TBC: Reaction Microscopy

Speaker: Thomas Pfeifer

19 Condensed Matter: Charge, Spin and Phonon Dynamics

Speaker: Hermann Dürr

20 FLASH Science Strategy for the Coming Years

Speaker: Markus Guehr

21 Adjourn