General Lab Information

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User Guide | Applying for Beam Time

User Access Policy

User access to beam time is based on (1) proposals that are subjected to peer review that is fair, clear, and expedient, that is sensitive to the needs of users, and that recognizes contributions that improve the overall scientific program, and (2) the principle that all proposals receive a finite amount of beam time for a limited duration that is justified by the need for beam time of the proposed work.

Access Modes and Proposal Lifecycle

There are three modes of user access to beam time at NSLS-II: General User (GU) access, Partner User (PU) access, and Beamline Discretionary Time (BDT) access. The life cycle for GU and PU access to beam time involves the following steps: proposal submission, proposal review and award of beam time, beam time allocation, beam time scheduling, carrying out the work, and reporting the results. BDT access involves scheduling, carrying out the work, and reporting the results but is reviewed retrospectively. Full details of the proposal process

Beam Time Approval

GU and PU access require peer review of proposals through a central review process managed by NSLS-II that utilizes Proposal Review Panels (PRPs). Beam time is allocated to GU proposals through recommendations of the PRPs. Beam time is awarded to PU proposals by NSLS-II management via a Partner User Agreement based on recommendations from the PRPs and the assessment of NSLS-II management. Beamline staff may receive beam time by being part of a GU proposal or a PU proposal. In addition, beamline staff may also be allocated beam time by beamline management using Beamline Discretionary Time. The award and utilization of all beam time, regardless of access mode, is subject to periodic review by the Science Advisory Committee (SAC).

Beam Time Allocation

A minimum of 50% of the available user beam time on every beamline shall be allocated by NSLS-II to a combination of GU, BAG, and RA proposals every run cycle. Up to 35% of the available beam time may be allocated by NSLS-II to one or more PU proposals in response to their beam time requests for that run cycle. Up to 15% of the available beam time may be allocated at the discretion of beamline management every run cycle for BDT access, typically by beamline staff.