Advanced Photon Source

An Office of Science National User Facility

Scientific Advisory Committee Policy

The APS Scientific Advisory Committee (SAC) advises the Associate Laboratory Director for the APS (APS/ALD).

  • To provide advice on the scientific direction and strategic plans of the APS.
  • To evaluate the overall performance, scientific output, and future plans of all APS beamlines.
  • To assess impacts of changes in accelerator performance and design on the scientific direction of the APS.
  • To evaluate Letters of Intent and scientific proposals for new and reconstituted beamlines.
  • To review proposals for Partner User access (an access mode that guarantees 10-30% of the beam time per year on any APS-operated beamline for up to three years).
  • To assist the APS with development of policies, as appropriate.
  • To provide advice on any topic as requested by the APS/ALD.

A SAC Board will consist of 14-18 members, comprised of the individuals listed below.


      A Chair will be appointed by the APS/ALD and will sit for a minimum term of three years.    

      Appointed members (from a diverse array of scientific/technical disciplines), serving staggered three-year terms, are renewable at the discretion of the APS/ALD

      APS Users Organization Chair, ex-officio

      APS Partner User Council Chair, ex-officio

      APS Machine Advisory Committee Chair,* ex‐officio

      APS Experimental Systems Advisory Committee Chair,* ex-officio


*for the duration of the APS-U project.


In general, the SAC will hold two meetings each year, usually in March and November. The schedule for these meetings will be set for several years in advance and posted on the SAC website. However, if needed, the SAC Chair and the APS/ALD can call special meetings of the full SAC.

The agenda for each SAC meeting , which will include a specific charge, will be prepared by the APS in conjunction with the SAC Chair. At the conclusion of the meeting, the SAC Chair will address this charge orally in a close-out session; a formal written response to the charge will be sent to the APS within a month and attached to the formal minutes of each meeting. The meeting agenda may also include an oral briefing from the Chairs of the APS Machine Advisory Committee and the Experimental System Advisory Committee.

As an important part of the SAC responsibilities is to review beamline performance, at each SAC meeting, the SAC will hear reports from stand-alone reviews conducted by Beamline Review Panels, each chaired by a member of the SAC. After the SAC approves these reports and recommendations, they will serve as guidelines for the next review of these beamlines. A separate policy, “Policy and Procedures for Reviews of Beamlines at the APS,” describes the process used for these reviews.

Adopted January 2017


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