LCLS Run 24 Call for Proposals

LCLS Call for Proposals for period: March 2025 – July 2025 (Run 24 Hard X-rays and Soft X-rays)

Submission Deadline: 11 September 2024 (4:00 PM Pacific Time)

We are pleased to announce the call for LCLS Proposals for Run 24. 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.

In the previous run, the new SC machine demonstrated 8 kHz and for  Run 24, the superconducting accelerator is expected to be operated up to 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 three soft X-ray instruments for user proposals (TMO, chemRIXS and qRIXS). We also expect to make available to the user community the second TMO endstation (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 (XCS, MFX, CXI & MEC). In Run 24, the XPP instrument will not be available as it is undergoing a rebuild for the LCLS-II-HE upgrade. We expect most of the scientific capabilities typically supported at XPP to be feasible at the other hard X-ray instruments, in particular XCS. Please contact LCLS Instrument Scientists to discuss instrument options for your proposal.

For Run 24, Proposals must be submitted through the new Universal Proposal System (UPS)

The UPS makes use of ORCID authentication to provide access to the system using your existing ORCID credentials. If you do not already have an ORCID, you can register with ORCID now or on your first login to UPS. For information about this new system and to learn more about the features and functionality of this new tool please visit the link below:

Universal Proposal System Information

A Virtual LCLS “Town Hall” User Meeting to discuss Run 24 will be held at 9:00 am Pacific Daylight Time on August 20, 2024.

User proposals for the soft X-ray instruments (TMO, chemRIXS and qRIXS) using LCLS-II superconducting beam.

TMO

The Time-resolved Atomic, Molecular and Optical Science instrument (TMO) was developed to study the dynamics of isolated quantum systems using charged particle spectroscopy, pump/probe methodologies, and/or nonlinear X-ray interactions. The TMO instrument will continue to be available for User experiments in Run 24 providing the opportunity to make use of the new superconducting LCLS-II accelerator. Run 24 proposals are expected to make use of the capabilities available at the first interaction point (IP1) of the TMO instrument. We will offer multiple standard configurations for Run 24, the first configuration features the magnetic bottle electron time-of-flight spectrometer (MBES) at IP1. The second configuration features the energy- and angle- resolving spectrometer (MRCO) again at IP1.  or the reaction microscope (DREAM) currently being commissioned at the second interaction point (IP2). What is new for Run 24 is the offer a third standard configuration at IP2 featuring the new reaction microscope (DREAM) endstation. This standard configuration will feature ion detection capabilities coupled to one of our 33 kHz Yb-based laser systems. Electron detection capabilities will be offered as a non-standard (at-risk) configuration. For more information please check our website and/or contact Instrument Lead James Cryan (jcryan@slac.stanford.edu) with any questions.

chemRIXS

ChemRIXS is a dedicated instrument to study condensed phase chemistry with pump-probe spectroscopy using high repetition rate soft X-rays. For Run 24 chemRIXS will be available for general user proposal using the high repetition rate LCLS-II beam at the anticipated 33 kHz repetition rate. The liquid standard configuration of chemRIXS is optimized for time-resolved RIXS and XAS (fluorescence yield and/or transmission mode) experiments using liquid jets in combination with the OPCPA laser system. For more information please check our website and/or contact Instrument Lead Kristjan Kunnus (kristjan@slac.stanford.edu) with any questions.

qRIXS

Starting in Run 23 the qRIXS instrument is expected to begin full technical commissioning.  The qRIXS instrument is designed to support a wide variety of experimental techniques, such as transient X-ray absorption, diffraction, reflectivity and RIXS.  An Early Science program, which is open to participation from the user community, is expected at the start of Run 24.  We anticipate that qRIXS will be made available for general user proposals using high repetition rate X-rays in the Run 24 call for proposals. For more information please check our website and/or contact Instrument Lead Georgi Dakovski (dakovski@slac.stanford.edu) with any questions.

Early Science using the superconducting high repetition rate accelerator

Participation in the Early Science program by the community for TMO-DREAM and qRIXS is still open, based on a set of experiments selected from an earlier call. Interest in participation should be directed to the following individuals:

User proposals for the Hard X-ray Instruments using the 120 Hz accelerator

The hard X-ray instruments of LCLS (XCS, MFX, CXI & MEC) will be available using the 120 Hz accelerator as in previous LCLS runs.

Proposals that make use of the Standard Configurations available on each of the Hard X-ray Instruments are highly encouraged, including short proposals that can make use of a more limited amount of beam time with higher likelihood of scientific success using those standard configurations.

LCLS Hard X-ray Instrument Contacts:

Proposal Types Available (for all instruments)

(1) General User proposals

A Proposal Template has been created to provide guidance on the format and structure of submissions. Users are strongly encouraged to follow this guidance, to help ensure that appropriate information is supplied to the Proposal Review Panel (PRP). This template along with updated proposal preparation guidelines will also be discussed during the Virtual Town Hall on August 20, 2024.

Proposals that can be scientifically successful using fewer than the typical 5 shifts are acceptable if the scientific needs are consistent with a shorter experiment. Proposers are asked to make it clear in their proposals that level of risk and scientific ambition is consistent with the number of shifts requested.

Standard Configurations: For Run 24, LCLS will continue to emphasize the use of Standard Configurations, where a target of 50% or more of the beam time is expected to be awarded to experiments utilizing the many configurations available. These provide a defined platform for running many similar experiments efficiently, leading to more users and experiments being allocated beam time. Proposals that make use of the Standard Configurations available are highly encouraged, including shorter experiments that can make use of a more limited amount of beamtime with higher likelihood of scientific success using a standard configuration.

Standard Configurations proposals require the inclusion of a parameter table, which can be found on the instrument-specific website. Users are strongly encouraged to contact the relevant instrument scientists to discuss and plan their proposals of any kind, but especially those that use (or could be adapted to use) Standard Configurations.

The Hard X-ray Standard Configurations continue to evolve to meet the needs of the scientific community and some have been updated. Please note the following additions:

MEC: MEC will be accepting rapid access proposals (see below) for laser-only VISAR shots.

IFE Science: Proposals to the MEC science area that address inertial fusion energy (IFE) priority research opportunities (PROs) are strongly encouraged. There is a goal of scheduling up to 50% of MEC science experiments in the IFE area, consistent with recent guidance from DOE. Such proposals should be clearly indicated as addressing IFE, such as by identifying the relevant PROs from the 2022 IFE Basic Research Needs (BRN) Workshop Report. These proposals will be reviewed by a sub-panel of the MEC PRP consisting of experts in IFE science in collaboration with LaserNetUS, alongside a sub panel for general MEC science.

For more information on any aspect of MEC, please contact Instrument Lead Eric Galtier (egaltier@slac.stanford.edu) with any questions.

(2) Short-form proposals

LCLS offers three mechanisms for short proposal submissions: Data Set Collection, Rapid Access, and Protein Crystal Screening. Each of these mechanisms has specific requirements, and use a specific short proposal form (link to forms). Please contact Christopher Kupitz (ckupitz@slac.stanford.edu) for additional information and guidance on any short-form proposal option.

  1. Data Set Collection proposals are tailored to experiments where one or two shifts would be sufficient to complete an existing partial data set, suitable for publication. As part of the Data Set Collection proposal your science case should justify why your experiment can be accomplished in 1-2 shifts, and should reference the previously reviewed proposal (and previous beam time). Beam time availability for these proposals is contingent on the Standard Configurations schedule. Please contact Christopher Kupitz (ckupitz@slac.stanford.edu) if you intend to submit a Data Set Collection Proposal.
  2. Rapid Access proposals are welcome at any time during the Run cycle, although such access is constrained and dependent on the requested configuration's availability. Rapid Access proposals should typically target Standard Configurations and must articulate why urgent access is needed. Access has typically been aimed at structural biology studies (e.g. COVID research) but will be considered for any subject area with an appropriate case, subject to facility availability.
  3. Protein Crystal Screening (PCS) proposals will be included in Run 24. The PCS program is for new Users to get beam time experience, or new projects that need half a shift (6 hours) to test samples, in preparation for a full proposal submission. Beam time availability for these proposals is contingent on the Standard Configurations schedule.

Modes of Beam Operation:

For up-to-date information on LCLS performance, please contact the respective instrument scientist listed above, and see the Machine FAQ and the Machine Parameters table, which includes a Multi-Color Pulse Mode Table.

LCLS Scientific Department Head Contacts (for general inquiries when preparing proposals):

Submitting LCLS Proposals

LCLS encourages scientists from diverse fields and backgrounds to propose experiments utilizing the facility’s capabilities. New users are particularly welcome. Users are encouraged to review the LCLS instrument descriptions and contact LCLS staff to discuss technical capabilities and proposed experiments (see Scientific Department Head and Lead Instrument Scientist contacts above). These staff will provide advice on how to translate your scientific ideas into an LCLS experiment, and can help introduce new users to potential partner user groups if desired. Communication with the LCLS team is strongly encouraged to help maximize your chances of success.

Access to LCLS is open to the international community, with selection based on scientific merit. There is no charge to conduct experiments at LCLS, and the facility is able to help with the costs of performing experiments (e.g. consumables). However, users are responsible for their own travel expenses.

Register as a user and submit LCLS proposals through the NEW Universal Proposal System (UPS)

The Universal Proposal System (UPS) is a collaboration between the Advanced Photon Source (APS) at Argonne National Laboratory, the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory, and the Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory. Registration in UPS is required for all members of the proposal team (Principal Investigators and Co-Proposers) and is quick and easy using your existing ORCiD credentials.

For information about this new system and to learn more about the features and functionality of this new tool please visit the link below:

Universal Proposal System Information

Read the proposal preparation guidelines, along with information on new standard configurations, and the proposal review process prior to writing your proposal.

A Proposal template has been created to provide guidance on the format and structure of proposal submissions. This template along with updated proposal preparation guidelines will also be discussed during the Virtual Town Hall.

SSRL Beam Time tied to LCLS Experiments

For some LCLS proposals, the science case can be significantly enhanced by having access to SSRL beam time in addition to proposed LCLS time. SLAC will consider a limited number of proposals that make a strong scientific case for beam time access to SSRL. These proposals should indicate how much time is requested, when the time would be needed relative to the LCLS time, as well as which SSRL beamline would be needed. If users have questions about which SSRL beamlines would be appropriate for the proposed scientific goals, please contact Piero Pianetta (pianetta@slac.stanford.edu). Scheduling of time across facilities is complicated and availability depends strongly on which of the SSRL beamlines is requested.

Timeline for Run 24

Run CycleProposal TypeSubmission Deadline
24Regular User & Data Collection ProposalsSeptember 11, 2024
4:00 PM (Pacific Time)
24Protein Crystal Screening (PCS) ProposalsOctober 8, 2024
4:00 PM (Pacific Time)

A Virtual LCLS “Town Hall” User Meeting will be held at 9:00am Pacific Daylight Time on August 20, 2024.

This webcast meeting will be held to inform potential users about developments at LCLS before the upcoming LCLS proposal deadline. LCLS staff will inform the community about the latest capabilities and will be available for Q&A.