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

Requirements for Beamline Restarts After the APS Upgrade Shutdown

This checklist defines the requirements for CAT and XSD beamlines to return to operations after the APS Upgrade (APS-U) long shutdown. This will ensure that technical and administrative requirements are met in order to receive permission from APS management to bring individual beamlines back into operations.

All beamlines need to meet pre-beam requirements and undergo commissioning before returning to general user (GU) operations.

  • PSC Design Review Committee (PDRC) review – Examines the updated final beamline design and radiation safety aspects (new ray tracings will be required).
  • Check-out – Testing of new equipment, systems without beam.
  • Ops commissioning – First beam and shielding verification.
  • Technical commissioning –Testing of the beamline with beam.
  • Scientific commissioning and early experiments.
  • Restart of the general user program.

Each of these requirements will be described below with an APS point of contact (POC) as appropriate.

There is an additional requirement for returning a CAT beamline to the scientific commissioning stage.  CAT beamlines/sectors include all beamlines/sectors that are entirely or mostly funded for operations with resources other than the APS Operations budget. This includes beamlines/sectors where the APS is a minority partner. The additional requirement is:

  • An updated and approved CAT Management plan (See Appendix for details).

PDRC Review

To come online after the shutdown ends, every beamline at the APS will require a review by the PSC Design Review Committee (PDRC). An approved updated Final Design Report (FDR) for each beamline will include:

  • Sector layout, including beamline layout, egress aisles and locations of Personnel Safety System (PSS) search and secure hardware.
  • Ray-traces for the new upgraded APS source.
  • Component reference table.
  • Changes to any shielding or Radiation Safety System (RSS) component.
  • Thermal analysis for RSS components.
  • Secondary Bremsstrahlung analysis (required if you are scattering primary Bremsstrahlung radiation with beamline optics).
  • Engineered Safety Systems other than the PSS/Equipment Protection System (EPS).
  • All relevant PDRC review recommendations adequately and formally closed out.

Beamline managers should work with APS and APS Upgrade staff if assistance is required for ray-tracing, heat load calculations, etc.  

APS POC:  Patti Pedergnana   

References:     APS-U Beamline Modification Template (Download) 
                        Record of Decision for Remaining APS-U Project Beamline Design Reviews (Download)
                        APS Beamline Final Design Report Guide (Download) 


Check-out is defined as testing of new equipment and systems without the beam. This is to be performed by the relevant beamline staff.

APS POC: none
References: none

Ops Commissioning

The ops commissioning process is controlled and performed by the Commissioning Readiness Review Team (CRRT). Before the first beam can be delivered and shielding verification can begin, the CCRT will verify that the following tasks have been completed:

  • Approval of an updated FDR by deputy ALD for operations.
  • Front end is operational.
  • Insertion device is operational.
  • Beamline work is verified as complete:
    • Survey and alignment complete.
    • PSS/Beamline Equipment Protection System (BLEPS) operational and verified.
    • All critical components tagged, logged into tracking system by Experiment Floor Operations Group (EFOG).
  • CRRT procedure for ops commissioning approved by CRRT chair.
    • Detailed, step-by-step plan covering first beam/shielding verification that is developed by CRRT in consultation with beamline staff.
  • Authorization by the deputy ALD for ops for the beamline to be brought online.

Once authorization for the beamline to be brought online has been received, first beam and shielding verification can commence. Every shielded enclosure and section of shielded transport is required to undergo shielding verification after the shutdown ends.

For ID beamlines, the detailed procedure for ops commissioning with beam will depend on the individual beamline, but in general will be done in phases. This will involve at least two visits to the beamline separated by a few days, with possible subsequent visits for new construction or if issues are encountered. 

For a more detailed process for your beamline, contact the APS point of contact.

APS POC: Dean Haeffner 
References: CCRT Requirements for Beamline Restarts (Download)

Technical Commissioning

Testing of the beamline with beam is defined as beamline technical commissioning and is controlled and performed by beamline scientists. Technical commissioning includes, but is not limited to, debugging systems, measurement of beam properties, measurements on standards, etc. This step can begin before ops commissioning is complete (for instance before Step 3 - closed gap/full power) by setting ID gap limits. Our estimation is that technical commissioning should take four weeks or less for most beamlines and 12 weeks for new or majorly reconstructed beamlines.

APS POC: none
References: none

Scientific Commissioning and Early Experiments

Note:  For CAT beamlines, the CAT must have an updated and approved management plan before scientific commissioning and early experiments begin. Details of the contents of the management plan can be found in the appendix of this document. CATs requesting an exemption to the 50% general user rule should submit (at least) the Operational Plan portion of their management plan by October 31, 2023, for review by the APS Scientific Advisory Committee at the November 2023 meeting.  

APS POC: Dennis Mills
References: BES Light Source Partnership Model (Download)

Scientific commissioning is managed by beamline staff.  During this time, CATs may invite members to participate and for XSD limited outside users can be considered.  For the APS-U feature beamlines, a call will be made for early experiment proposals that will be reviewed.  Scientific commissioning should last no longer than four weeks for most beamlines, but may last longer for APS-U feature beamlines.

APS POC: Jacki Flood for feature beamline proposals
References: none

Operations with General Users

General user operations should commence as soon as the beamline is functional. It is our plan to have a call for general user proposals so that they can be reviewed and ready to go as soon as a beamline is available for general user operations. Since the schedule for beamlines to be ready for GUs will vary, the current plan for the first call for GU proposals will be to score the proposals but not have time allocated by the Beamtime Allocation Committee (BAC). This will allow beamline managers to allocate time to teams with well-reviewed proposals as the beamlines come back to full operational status.

APS POC: Jacki Flood for General User Program
References: none

APPENDIX: CAT Management Plan Guidelines

The collaborative team operating the beamline shall have a management plan that is current and includes:

  • Introduction.
  • Institutional members of the collaborative team and the terms of the partnership.
  • Collaborative team organization and staffing.
  • Scientific scope/planned research programs.
  • Financial and staffing plan.
  • Safety plan.
  • Operational plan.
  • Schedule – a high-level plan and schedule for transition to operations.


Should include a brief statement of the mission of the CAT, technical scope, and explanation of the user community the CAT supports.

Institutional Members and the Terms of the Partnership

The plan should include a list of the institutional CAT members and the terms of the partnership describing the responsibility and rights of the partner institutions, including what is expected from each and what each can expect in return.

Collaborative Team Organization

The description of the collaborative team organization should identify the key roles and responsibilities for the operations of the beamlines and the management of the collaborations.  An organization with external advisory committees or oversight bodies should be included.

Scientific Scope/Planned Research Programs

The management plan should provide an overview of the projected scientific scope and research areas that the CAT members will be pursuing for the next five years and a summary of programs supported on the beamline (4-6 pages). The plan should call out any significant changes (addition and/or deletion) to pre-upgrade programs/capabilities. The scientific scope and planned research portion of the management plan must be updated before each CAT tenure review.

Financial and Staffing Plan

The financial plan should identify the expected operations funds required to operate the beamline(s) and the expected funding commitment from the partner institutions/funding agencies. CATs must provide staffing levels and an annual budget profile for the next five years.  Per the new BES partnership model, CATs are expected to provide a minimum of two staff members per beamline and sufficient funding for modernizing the beamlines regularly to support a scientifically competitive GU program on the beamline. The management plan should confirm conformance to this policy or provide an explanation of why two staff members won’t be required to operate the beamline, taking into account the nature of the experiments and end stations in question. An estimate of the annual level of funding for modernization of the beamline should also be included. Staffing levels and modernization funding will be explicitly evaluated in tenure reviews. The plan should also identify any resources expected from the APS.

Safety Plan

The safety plan should include an updated list of key safety positions and names of the individuals holding these positions, and any special safety concerns related to expected CAT activities.

Operational Plan (GU and Member Access Plan)

The operational plan should describe the allocation of the baseline beamtime available between the general users, collaboration members and beamline staff. Any special requirements for restrictions on general users on the beamline(s) should be identified. Effective at the end of the dark time, the minimum percentage of beam time available to general users will be increased to 50%. CAT members can compete for the general user time on their beamline(s) through the standard APS GU system. Exceptions to the 50% rule will be considered from industrial CATs and national security-driven CATs. The reason(s) why the CAT is requesting that less than 50% of beam time should go to general users, and any previous arrangements made with APS in lieu of the 50% general user requirement, should be provided. These exceptions will be reviewed by the APS Scientific Advisory Committee.


A high-level schedule for restart of operations should be provided. Planned key dates, e.g. completion of construction or reconfiguration of beamline, goal for start of technical commissioning, goal for restarting the general user program, etc. should be included.

Management plans are reviewed by a committee chaired by the PSC deputy ALD for science.

APS POC: Dennis Mills
References: none