December 19, 2023

LCLS Run 23 Call for Proposals & Virtual Town Hall Meeting

LCLS Call for Proposals for period: August 2024 – February 2025 (Run 23)

Submission Deadline: 21 February 2024 (4:00 PM Pacific Time)

We are pleased to announce the call for LCLS Proposals for Run 23. This Run will offer capabilities on the soft X-ray instruments using the beam from the new LCLS-II superconducting high repetition rate accelerator. It also offers a continuation of the existing hard X-ray instruments, with dedicated use of the LCLS copper accelerator.

For this Run, the superconducting accelerator is expected to be operated at 33 kHz. Detailed performance parameters will be subject to lessons learned during commissioning, and so proposals should be adaptable to a range of likely performance levels. Close coordination with the relevant instrument scientist teams is strongly advised in the preparation of your proposals.           
The soft X-ray undulator will primarily be served by the superconducting accelerator, providing beam to the first two soft X-ray instruments for user proposals (TMO and chemRIXS). In parallel, the facility will undertake commissioning of the next suite of instruments and endstations (qRIXS, TXI, and TMO-DREAM).

The copper accelerator will continue to operate up to 120 Hz for the hard X-ray instruments, providing vertical polarization and up to 25 keV X-rays in the fundamental, as well as rapid tuning / scanning capability using the variable gap system. This undulator will provide beam to the suite of hard X-ray instruments (XPP, XCS, MFX, CXI & MEC).

User proposals are sought for these soft instruments and all the hard X-ray instruments - for full details please visit:

Virtual Town Hall Meeting

A Virtual LCLS “Town Hall” User Meeting to discuss Run 23 was held at 9:00am Pacific Daylight Time on January 30, 2024.

Recordings of the plenary session and breakout discussion for each instrument can be accessed below.


Topic PresenterPresentations
Current LCLS Status & PlansMike Dunne




User Executive Committee UpdateNicholas Hartley
Accelerator Plans for Run 23Axel Brachmann / Tim Maxwell
New instrument UpdateJames Cryan & Georgi Dakovski
Hard X-ray instruments brief overviewSebastien Boutet
Data systemsJana Thayer

Breakout Sessions

TMOJames CryanVideo & Slides
MECEric GaltierVideo & Slides
MFXLeland GeeVideo & Slides
qRIXSGeorgi DakovskiVideo & Slides
XCSMatthieu CholletVideo & Slides
chemRIXSKristjan KunnusVideo & Slides
CXIMeng LiangVideo & Slides
XPPTakahiro SatoVideo & Slides
TXIAndy AquilaVideo & Slides