Proposal Review Process

LCLS management works very closely with the LCLS Scientific Advisory Committee (SAC), Proposal Review Panel (PRP) and the Users' Executive Committee (UEC) to develop a fair and transparent external peer review process.

Proposals must provide sufficient information to evaluate the impact, originality, need for LCLS, scientific risk, prior results, as well as technical feasibility. Proposal evaluation criteria include:

  • Scientific Impact: Does the proposal address a question that, if successfully answered by the proposed experiment, will have a strong impact either on the scientific field or technological area addressed by the research?
  • Originality/New Scientific Field: If successful, does the proposal open a new field?
  • Need for LCLS/Experimental Plans: To what extent is LCLS critical for the success of this proposal? Can other techniques or facilities provide similar information about the scientific question?
  • Scientific Risk: Evaluate the probability that the proposed research will yield significant new results.
  • Prior Results: Evaluate success or progress of prior experiments.
  • Feasibility: LCLS scientists conduct a preliminary technical feasibility review of submitted proposals.
  • Compatibility: Can the experiment be performed simultaneously with another experiment (i.e. can it be performed with monochromatic, hard X-ray beam)? Does the experiment require significant modifications to a LCLS instrument setup? We specifically encourage proposals that use monochromatic, hard X-ray beam and proposals that minimize instrument modifications.

Regular User Proposals

LCLS proposal review and ranking is carried out by the Proposal Review Panel (PRP) which includes ~80 international experts divided into several subpanels: Atomic, Molecular, Optical and Cluster Physics (AMO); Crystallographic Structure Determination of Biological Objects (BIO-C); X-ray Scattering, Spectroscopy, or Single Particle Imaging of Biological Objects (BIO-S); Chemistry, Soft Condensed Matter & Disordered Materials (CSD); Materials-Hard Condensed Matter (HCM); High Energy Density Science/Matter in Extreme Conditions (MEC); and Methods and Instrumentation (M&I). A description of the proposal review process follows.

The review process for Regular User Proposals begins as soon as each call for proposals is closed, with an on-site PRP meeting at SLAC approximately two months after the proposal deadline. Concurrent with the PRP review, LCLS scientists conduct a technical feasibility review of submitted proposals. Proposals determined not to be feasible may be removed from further consideration before the PRP meets, and the proposal spokesperson will be informed.

Users should indicate the appropriate PRP panel(s) to review their proposals when submitting proposals through the user portal. Proposals are reviewed by LCLS and the PRP Chairs to confirm that the distribution of proposals is appropriate for the expertise of the PRP or to reassign these proposals to more appropriate subpanels to facilitate consistency in the review and ranking process. Once the subpanel assignments are confirmed, the PRP chairs assign 2-3 reviewers for each proposal assigned to their subpanel. Additional reviews may be requested from other panels if the area of science extends beyond the primary subpanel. If the PRP lacks the necessary expertise to review any proposal, subpanel chairs may request ad hoc external peer reviewers to supplement the PRP review.

LCLS management provides clear guidance to PRP members to mitigate potential conflicts of interest.  See guidelines for managing potential Conflicts of Interest in the Proposal Review Panels.

In time for the PRP meeting, reviewers provide a written review for each assigned proposal summarizing their findings.

Subpanel chairs assign a 'Lead Reviewer' for each proposal, who presents the proposal during the subpanel deliberations. The panels define a prioritized list of proposals based on the criteria listed above. Prioritization between sub-panels is determined according to a pro-rata weighting based on the number of applications in each area. Within one week of the PRP meeting the subpanel chairs will provide comments on each proposal with sufficient detail to explain the basis of the panel's assessment, to help the proposal teams address any deficiencies and improve their proposals for a subsequent review cycle.

The ranked list of proposals will be the guide for LCLS management to award beam time. LCLS has the discretion to consider aspects beyond the strict ranking to make the final beam time allocation. Such consideration may include issues of programmatic and community diversity, access to new instruments, utilization of beamtime (e.g. via multiplexing and efficient use of standard configurations), funding restrictions and other aspects.

Scientific Campaign Proposals

Submission of a Scientific Campaign proposal requires advanced submission approval from the LCLS Director - based on a brief Letter of Interest (LOI) to be followed by further discussion with LCLS staff. Scientific Campaign proposals are to be submitted to the LCLS User Portal and identified as Scientific Campaign Proposals.

Scientific Campaign proposals will be evaluated according to the criteria defined above (for Regular User Proposals), with the following additional criteria:

  • Scientific scope and impact of the proposed research should be well above a Regular User Proposal as described above. This includes the following major elements:
    • Clear and compelling motivation based on “grand-challenge” scale science problem, addressing priority science mission (e.g. of DOE or others as appropriate). The science impact must be significant (and widely recognizable) with a high chance of success.
      Will the proposed sequence of experiments result in a qualitative advance on an important science challenge?
    • Well-defined scope and objectives, with clear justification for a series of beamtimes. This must include objective milestones of what is expected to be accomplished in each beamtime, and how this advances the larger goal of the Scientific Campaign.
      What scientific advance will be accomplished, how, by whom, and over what period of time?
      Could this be accomplished through a Regular User Proposal?
    • Clear and well-justified need for unique capabilities and expertise of LCLS, close partnership with the LCLS facility as evidenced by strong involvement of LCLS/SLAC staff, and clear explanation of all the essential needs for a successful Scientific Campaign, and how these needs will be met (e.g. other facilities, personnel, expertise, resources etc.)
      Is LCLS essential for the proposed Scientific Campaign?
      Is the proposed Scientific Campaign in the strategic interest (scientific and/or technical) of LCLS?
      Are all the other essential elements for success identified and arranged?

Scientific Campaign proposals will be evaluated by PRP members with relevant expertise, and by additional expert external reviewers as needed. The LCLS SAC will provide feedback and advice on the portfolio of Scientific Campaigns supported by LCLS.

Scientific Campaigns that are awarded beamtime will be required to provide regular updates and progress reports to the LCLS Director. Continuation of a Scientific Campaign will depend on the demonstration of suitable progress toward the identified goals. Scientific Campaigns that do not demonstrate suitable progress may be ended early, and directed toward the Regular Proposal process for the next run.

Protein Crystal Screening (PCS) Proposals

PCS proposals will be reviewed by the PRP BIO-C panel separately from the regular proposals. It is desirable to shorten the period between PCS proposal submission and beam time allocation to maximize flexibility and the ability to be reactive to novel samples or ideas. LCLS will aim to pre-allocate blocks of beamtime on CXI and/or MFX based on the overall demand. The expected amount of beamtime is approximately 10-12 shifts in every LCLS run. Proposals will be awarded beam time by LCLS based on the scientific recommendation of the Proposal Review Panel and other technical considerations by LCLS, including sample readiness, technical feasibility and scheduling constraints. A minimum of 2 months notice will be given to the selected user groups to allow for appropriate preparation.

  • Overlap with Regular LCLS Proposals
    • There is no restriction with regards to possible overlap or redundancy with regular LCLS proposals. Submission of PCS proposals similar or related to regular LCLS proposals are encouraged and will not adversely impact the rankings of either types of proposals. Regular LCLS proposals that do not receive beamtime may be considered for PCS if deemed suitable.

Submit your proposal through the user portal