The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

General User Proposals

General user proposals (GUPs) allow researchers from anywhere in the world to use the APS through a competitive access process. Details of the General User Program can be found in the APS Policy and Procedure for General User Beam Time

Log in to Proposal System


Submission deadlines:

New proposals and requests for beam time against existing proposals are accepted three times a year, in March, July, and October. A "rapid access" option is also available.

Review and allocation:

Proposals are peer reviewed and scored according to a set of review criteria. Time is allocated by a committee on the basis of scores and feasibility. The scores of unallocated proposals are "aged" or improved at each cycle as part of the allocation process. A user may appeal the outcome of a review.


Proposals expire in two years or when the number of shifts recommended in the peer review have been used, whichever comes first. Rapid access proposals, other than macromolecular crystallography proposals, are good for one cycle. 


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