Rapid Access Program Details

Rapid Access at CXI

Rapid Access experiments at CXI will be carried out using the Serial Sample Chamber in the standard CXI configuration, using the refocused X-ray beam from the 1 μm focus or straight beam as a parasitic measurement to a primary experiment, depending on scheduling constraints and at the discretion of LCLS.

Rapid Access will utilize the CSPAD 2.3M detector. Sample delivery will be via the standard liquid jet system which utilizes nozzles mounted on long rods inserted into a load-lock system. These nozzle rods are compatible with Gas Dynamic Virtual Nozzles (GDVN), Dual Flow Focusing Nozzles (DFFN), Lipidic Cubic Phase (LCP) jets as well as the Microfluidic Electrokinetic Sample Holder (MESH). 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 PCS beamtime within a time frame compatible with 12-hour parasitic runs and rapid turnaround between groups. Decisions on using alternative sample delivery systems are entirely at the discretion of the LCLS facility.

Rapid Access at MFX

Rapid Access experiments at atmospheric pressure are expected to be available at the MFX instrument with multiple options likely to be available including a goniometer system, allowing scanning of fixed-mounted crystals, and a liquid jet system compatible with various types of jets housed in a Helium enclosure. 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 available. The availability of all these systems for Rapid Access will depend on scheduling constraints and is entirely at the discretion of LCLS.

To facilitate Rapid Access at MFX, the MFX mirror will be driven partially into the main beam in the Far Experimental Hall and act as a wavefront divider. Consequently, it is expected that Rapid Access at MFX will have somewhat reduced transmission compared to normal experiments.

Other Experimental Geometries or Capabilities

Laser driven time-resolved studies are currently not within the scope of Rapid Access beam time. User provided mix and inject serial crystallography (MISC) will be considered. X-ray Emission Spectroscopy can be considered if the spectrometer has already been set up with the proper crystals for the element of interest.

Proposal Review and Beamtime Award

The Rapid Access proposals will be reviewed by a subset of the PRP BIO-C panel separately from the regular proposals and on a continuous basis. The goal is to shorten the period between  proposal submission and beam time allocation to maximize flexibility and the ability to be reactive to novel samples or ideas. 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. Upon approval, LCLS staff will coordinate with the selected user groups to ensure quick turnaround and scheduling while facilitating appropriate preparation.

Overlap with Regular LCLS Proposals

There is no restriction with regards to possible overlap or redundancy with regular LCLS proposals. Submission of Rapid Access proposals similar or related to regular or PCS  proposals are encouraged and will not adversely impact the rankings of either types of proposals.