General User Access to the Advanced Photon Source in Argonne, Illinois



The CLS@APS programme represents a partnership between the Canadian Light Source (CLS) and the Advanced Photon Source (APS) at Argonne National Laboratory in Illinois, USA. Through this arrangement, Canadians have access to techniques and beamlines at APS (some of which they helped develop), continue to aid in sector 20 development and operation, and promote the growth of the scientific community. Beamtime is currently set aside for Canadian use as follows:

User time obtained through this mechanism is via competitive peer review twice per year, emphasizing the excellence of science where there is intent to publish scientific results. 

Eligibility Criteria

To be eligible to apply for Canadian Access to the APS, the spokesperson must be affiliated with a Canadian university or college and have a CLS Institutional Agreement in place. If the spokesperson is a student or postdoctoral fellow, their Scientific Project Leader must be affiliated with a Canadian university or college.

Proposal Review and Ratings

All new proposals are reviewed for technical feasibility and scientific merit, which is decided by a peer review process. A proposal must receive a peer review score between 1 and 4 to be considered for allocation of beamtime. The score a proposal receives during this process will be used in allocating beamtime for the entire two years it is active. Active proposals will not be re-evaluated. Click here for details about the peer review evaluation criteria, rating scale, Peer Review Committee and notification of results.  

Beam Time Allocation & Scheduling

Prerequisite for applying for shifts at the APS is submitting a CLS Proposal to the CLS during its Call for Proposals.  An active CLS@APS proposal must then request shifts by submitting a CLS@APS Beamtime Request form for the appropriate APS Cycle by the APS Proposal Deadline

The allocation and scheduling of shifts is managed by the CLS@APS staff. Beamtime requests are prioritized each cycle based on peer review scores. The CLS@APS staff will also take into consideration scientific productivity as indicated by publications resulting from previous beamtime allocated at the APS via the CLS.  Please note, if multiple requests are received from the same team through the APS GUP and CLS@APS process for the same APS Cycle, then APS GUP would have first consideration. If awarded beamtime, no additional access would be provided through the CLS PUP.  If not awarded APS GUP beamtime, then you would be eligible to be considered for CLS PUP time based on score and availability of beamtime on requested beamline.

Users are responsible for requesting beamtime following the CLS Call for Proposals and abiding to all APS policies and procedures associated with participating in an experiment.


CLS promotes and encourages open communication between all users of the beamlines at CLS and APS. Appeals relating to proposal ratings and/or allocation will follow the process identified in the Appeals Guidelines.

How to Submit a CLS@APS General User Proposal

For general inquiries for beamtime for CLS@APS or to discuss your proposal details prior to submission, please contact CLS@APS beamline scientist Zou Finfrock.

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If you’re looking for information on how you can use CLS techniques in your research program, please contact us using this form.

Example queries may include: Feasibility around a potential experiment? A scientific problem we can help you solve? Is your question related to a specific technique? Do you want to know more about how to apply for beamtime?