Advanced Photon Source

Office of Science User Facilities

Proposal Types

All beam time at the APS (either non-proprietary or proprietary) must be requested each cycle through the web-based Beam Time Access System. In this system, a proposal describes an experiment and identifies the experimental team. A beam time request on a proposal identifies where and when the researchers want beam time. A proposal can have several beam time requests (BTR). Each use of beam is associated with a proposal, a beam time request, and an Experiment Safety Assessment Form (ESAF). For more details, see Concepts, Definitions, and Help.

General User Proposals
The General User Program allows researchers from anywhere in the world to use the APS through a competitive access process. 
CAT Member and Staff Proposals
Proposals from members and staff of Collaborative Access Teams (CATs) are short, do not expire, and are reviewed by processes developed by individual CATs. For CAT websites, see the Beamline Directory.
Industrial Measurement Proposals
This mode provides a way for industry users to perform one-time, usually nonproprietary measurements to investigate specific problems. 
Partner User Proposals
Partner users contribute to the development of the facility in exchange for reliable beam time. 
Facility Staff Proposals
Proposals from APS staff are very short, do not expire, and are reviewed through processes developed by the APS.


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