Data Set Collection (DSC)
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In cases where a short period of beam time (up to 1-2 shifts) using a suitable Standard Configuration should be sufficient to produce a full data set suitable for publication, data collection proposals are encouraged. These proposals should be submitted as regular proposals, but should be marked as ‘Data Collection’ in the title and can be shorter in length.
The focus will be to facilitate data collection for projects that are close to completion, or only need a short amount of beam time to reasonably achieve a full data set. To enable measurements within such a short time frame and maximize efficiency and the chances of success, these studies must be carried out with limited instrumentation flexibility to minimize the time impact of setup changes.
Only proposals utilizing established Standard Configurations will be supported. Proposals that can make use of multiplexed/parasitic beamtime alongside other experiments will have a higher likelihood of being able to be fielded. The availability of all these systems will depend on scheduling constraints. Please see the relevant instrument scientist to discuss which configurations are available for a given Run.
Example - Data collection at CXI
Data collection experiments at CXI can be carried out using the standard CXI configuration, the refocused X-ray beam from the 1 µm focus as a parasitic measurement to a primary experiment. Sample delivery can be via liquid and high viscosity jet systems as well as fixed targets in vacuum. User-supplied sample delivery systems or modifications to the existing system are allowable only if they are compatible with the existing systems and can be exchanged with the other systems used for DSC beamtime within a time frame compatible with 12-hour parasitic runs and rapid turnaround between groups.
Example - Data collection at MFX
Data collection experiments at atmospheric pressure are typically available at the MFX instrument. Multiple options exist, including a goniometer system, allowing scanning of fixed-mounted crystals, and a liquid jet system compatible with various types of jets. These systems can also be modified in principle for use of a variety of atmospheric pressure sample delivery systems. User-supplied systems may also be feasible.
DSC access is also available at other instruments. Please see the relevant instrument scientists for details.
Proposal Review and Beamtime Award
Data collection proposals will be reviewed by the PRP panel together with the regular proposals. LCLS will aim to pre-allocate blocks of data collection beamtime based on the overall demand. 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 2 months notice will be given to the selected user groups to allow for appropriate preparation.
Note that Rapid Access mechanisms are also available.
Overlap with Regular LCLS Proposals
Data collection proposals should differ in some significant way to a regular proposal by, for example, focusing on a reduced scope based on the need to complete a dataset from a prior beamtime, or focusing on the use of a robust LCLS configuration with a sample that only requires a limited amount of beamtime to return a meaningful dataset.
Data collection proposals are evaluated on the impact, originality, need for LCLS, scientific risk, prior results, as well as technical feasibility. Provide a descriptive title of your proposed experiment that you would be willing to be made public if awarded beam time.
The proposal text is limited to 2 pages in PDF format. Pages should have at least 1 inch margins and not less than 10 pt font. It should include the following information:
- Experimental Team: In a table, list the names, institution, email address of PIs and collaborators who would participate in the proposed experiment (e.g., sample prep, theory, data collection, data analysis). This section could also briefly mention directly-relevant previous work done by the team members.
- Scientific Case: Briefly explain the background and significance of your experiment. In particular, why is LCLS required for this experiment? Itemize the specific aims and particular questions you want to answer. Focus on the specific experiment and avoid broad discussions in general terms.
- Experimental Procedure: If the data collection proposal is related to one or more regular LCLS proposals that have been submitted or already received beam time, state this in the proposal. Tell us if you plan or have carried out supporting experiments at other facilities. Have simulations of the experiment been performed? What are the anticipated data rates? Provide a beam time plan, indicating what could be accomplished in the requested beam time. Describe any additional equipment you plan to bring to LCLS for the experiment. We strongly recommend that you contact LCLS instrument scientists before proposal submission to discuss capabilities and equipment needs before submitting a proposal.
- Technical Feasibility: Proposals must contain sufficient information for LCLS to review the proposal for technical feasibility. This information should include:
Which elements of the proposed instrument do you require for the proposal?
What additional equipment is needed, including detector, sample delivery/environment, temperature, pressure, etc.?
How do you plan to provide/organize the additional equipment?
- Experimental protocol
Describe the experimental geometry.
Calculate the expected signal rate/background.
Describe samples and concentrations, sample preparation and storage.
Describe local facilities that may be required.
*Safety related documents must be submitted during the safety management portion of the LCLS proposal submission process in the user portal. List and describe any safety concerns that may arise with samples you will examine, equipment you will use, or techniques you will perform (including any physical, chemical or biological hazards) and how these issues will be addressed in the experiment design.
Proposals are submitted through the User Portal.