1st Hard X-ray Self-seeding Workshop (HXRSS 2025)

Oct 15, 2025, 1:30 AM → Oct 17, 2025, 10:45 PM Asia/Seoul

PAL-XFEL Auditorium (PAL, Pohang, Korea)

Gianluca Geloni

We are pleased to announce the first Self-seeded FEL workshop will be held in Pohang, South Korea. This workshop aims to share new ideas and promote collaboration in self-seeded FEL techniques and their scientific applications.

Today, Self-seeding is the only scheme that provides hard X-ray FEL users with pulses of radiation characterized by high-brightness (an order of magnitude higher than SASE) and narrow-bandwidth (down to a fraction of eV). Four facilities, LCLS-I, SACLA, PAL-XFEL, and European XFEL, use a self-seeded scheme for narrow-band scientific applications. At upcoming CW XFEL facilities, like SHINE and LCLS-II, self-seeding is considered for advancing the scientific case.

The workshop topics will include X-ray FEL self-seeding techniques and their science cases, including their development and applications, discussions on collaboration, etc. During the workshop, all participants are invited to have a hands-on experience of joining the self-seeded FEL tuning and optimization team at the PAL-XFEL operation room.

Topics to be discussed:

• experiments (cool things we can do with it)
• current performance (or expected performance from facilities that will install it)
• developments and schemes (transmission/reflection, single/double chicane, harmonics, phase locking)

 

HXRSS_Workshop_PAL_timetable_20251015.pdf

Wed, October 15

7:30 AM → 8:20 AM Bus Pickup and Transfer to Venue

Bus pickup at Hotel Lahan

8:00 AM → 9:00 AM Registration

Breakfast(sandwich) at multipurpose room
&
Registration in front of PAL-XFEL auditorium

9:00 AM → 11:00 AM Session A: Introduction and perspectives

9:00 AM Workshop introduction and goals - general introduction to HXRSS

Speaker: Gianluca Geloni (European XFEL)

HXRSS2025_intro.pdf

9:20 AM Coherence Control and Limitation with HB SASE

Speaker: Philipp Dijkstal (Paul Scherrer Institut)

HB_SASE_HXRSS.pptx

9:45 AM Extrapolation of EEHG towards higher photon energies

Speaker: Enrico Allaria (Elettra - Sincrotrone Trieste)

10:10 AM Overview of cavity based XFEL activities

Speaker: Nanshun Huang (Shanghai Optoelectronic Science and Technology lnnovation Center)

10:35 AM The cavity-based XFEL demonstrator at the European XFEL

Speaker: Patrick Rauer (Deutsches Elektronen-Synchrotron DESY)

FirstLasingCBXFEL.pptx

FirstLasingOfCBXFELEuXFEL

11:00 AM → 11:20 AM Coffee Break

11:20 AM → 1:30 PM Session B: Current performance

11:20 AM Self-seeding FEL for experiments requiring energy scans at PAL-XFEL

Speaker: Haeryong Yang (Pohang Accelerator Laboratory)

11:45 AM High repetition rate HXRSS system at the European XFEL

Speaker: Shan Liu (DESY)

12:10 PM Recent activities of hard X-ray self-seeding at LCLS

Speaker: Alberto Lutman (SLAC)

12:35 PM Daily optimization of reflection self-seeding

Speaker: Dr Toru Hara (RIKEN SPring-8 Center)

1:00 PM Discussion (B)

1:30 PM → 2:30 PM Lunch

2:30 PM → 4:30 PM Session C: Developments and schemes (I)

2:30 PM Self-seeding option and status at SHINE

Speaker: Tao Liu (Shanghai Advanced Research Institute, CAS)

2:55 PM Bandwidth and signal to noise ratio control for hard X-ray self-seeding

Speaker: Tianyun Long (DESY)

3:15 PM Pulselength Control in Self-Seeding

Speaker: Philipp Dijkstal (Paul Scherrer Institut)

3:35 PM Development and applications of combined self-seeding and crystal optics

Speaker: Ichiro Inoue (The University of Tokyo)

4:00 PM Discussion (C-I)

4:30 PM → 6:00 PM Self-Seeding Demo.

4:30 PM Accelerator Demo.

4:30 PM Beamline Demo.

6:00 PM → 8:00 PM Banquet

POSCO International Center, Buffet

8:00 PM → 8:30 PM Move to Hotel Lahan

Thu, October 16

7:30 AM → 8:20 AM Bus Pickup and Transfer to Venue

Bus pickup at Hotel Lahan

8:00 AM → 9:00 AM Breakfast

Breakfast(sandwich) at multipurpose room

9:00 AM → 11:10 AM Session C: Developments and schemes (II)

9:00 AM Generation of tunable phase-locked hard X-ray pulses

Speaker: Philipp Dijkstal (Paul Scherrer Institut)

9:20 AM Comparison same bunch and fresh bunch self seeding at PAL

Speaker: Myunghoon Cho (Pohang Accelerator Laboratory)

(20251010)ss.pptx

9:40 AM Self-seeding at higher harmonics

Speaker: lu cao (Deutsches Elektronen-Synchrotron DESY)

10:00 AM Self-seeding systems for CW FELs - Remote

Speaker: David Reis (Stanford PULSE Institute)

10:20 AM Advanced studies at the LCLS - Remote

Speaker: Aliaksei Halavanau (SLAC National Accelerator Laboratory)

10:40 AM Discussion (C-II)

11:10 AM → 11:30 AM Coffee break

11:30 AM → 1:15 PM Session D: Experiments (I)

11:30 AM IXS challenges - Remote

Speaker: Mark Dean

11:55 AM Dynamics of compressed gas/liquid (CO2, water, alcohol)

Speaker: Matthias Ihme (Stanford University)

12:20 PM Water dynamics

Speaker: Robin Tyburski (Stockholm University)

12:45 PM Discussion (D-I)

1:15 PM → 2:15 PM Lunch

Lunch at multipurpose room

2:15 PM → 3:35 PM Session D: Experiments (II)

2:15 PM Time-resolved Bragg Coherent X-ray Diffraction Imaging of Ferroelectric Transition

Speaker: Hyunjung Kim (Soagng University)

2:40 PM 3D time-resolved single-shot imaging

Speaker: Changyong Song (POSTECH)

3:05 PM Discussion (D-II)

3:35 PM → 5:05 PM PAL-XFEL Tour

5:05 PM → 5:35 PM Move to restaurant

5:35 PM → 7:15 PM Social Dinner

Fri, October 17

7:30 AM → 8:20 AM Bus Pickup and Transfer to Venue

Bus pickup at Hotel Lahan

8:00 AM → 9:00 AM Breakfast

Breakfast(sandwich) at multipurpose room

9:00 AM → 10:45 AM Session D: Experiments (III)

9:00 AM Single-shot structure determination under high magnetic field over 100 T

Speaker: Akihiko Ikeda (University of Electro-Communications, Tokyo, Japan)

9:25 AM Atomic-scale imaging of strong-field optically induced electron motion in imperfect crystals - Remote

Speaker: David Reis (Stanford PULSE Institute)

9:50 AM Scandium-45 Nuclear-Clock Isomer driven by hard X-ray self-seeding - Remote

Speaker: Yuri Shvydko (Argonne National Laboratory)

251017-Sc45-XFELs.pdf

10:15 AM Discussion (D-III)

10:45 AM → 11:05 AM Coffee break

11:05 AM → 1:20 PM Session D: Experiments (IV)

11:05 AM Application of hard X-ray self-seeding at higher photon energies

Speaker: Angel Rodriguez Fernandez (European XFEL)

11:30 AM Nonlinear spectroscopy utilizing two-color pulses composed of seeded and broadband beams

Speaker: Thomas Linker (SLAC)

HXRSS_Linker.pptx

11:55 AM Ultrafast Photocatalytic Reaction Dynamics Probed by HERFD-XAS with Self-seeded XFEL Pulses

Speaker: Tae Wu Kim (Kyung Hee University)

12:20 PM Discussion (D-IV)

12:50 PM Overall discussion and wrap-up

1:20 PM → 2:00 PM Lunch box pickup & Move to Pohang KTX station