How to Request & Access Beam Time

Step 1Submit a proposal that summarizes proposed research plans

Step 2Submit beam time requests

SSRL Beam Line Scheduling Information

Step 3Review SPEAR & beam line schedules

Step 4:  ACCEPT beam time & SUBMIT SUPPORT REQUEST listing experiment participants

User Registration & Assistance

Step 5:  Review & complete user 'To Do' list when assigned beam time


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Step 1: Submit a proposal that summarizes proposed research plans.

Review the guidelines for proposals and scheduling procedures. Standard proposals can be submitted through the user portal three times each year:

In addition to standard general user (GU) proposals, users may submit a Rapid Access or Letter of Intent proposal at any time through the user portal to access a small amount of beam time to test the feasibility of new ideas.

Research teams are discouraged from submitting multiple proposals unless the proposed research is unrelated. Multiple proposals from members of the same research team will be flagged during the peer review process (may be combined and limited in lifetime and/or beam time allocations).

SSRL scientists are available to answer questions about SPEAR, beam lines, capabilities, science or  techniques to help users plan their experiments.

Submitting a proposal is the first step to access beam time at SSRL. SSRL proposals are peer reviewed and competitively rated by the SSRL Proposal Review Panel (PRP) on a scale from 1 (highest) to 3 (lowest). The PRP also assists with beam time allocations, for example recommending adjustments to total number of shifts estimated for proposals or indicating if the proposed experiment should have a shorter lifecycle or a limited amount of beam time to determine feasibility or encourage new exploratory studies. Successful proposals are eligible to request and may be awarded beam time on SSRL beam lines, with priority given to the highest rated proposals and those which demonstrate efficient and productive use of beam time. Proposals rated better than 1.4 are most likely to receive their optimal number of shifts on their first choice beam line; other requests are accommodated as beam time is available.

SSRL operates as a dedicated synchrotron radiation source for approximately nine months per year (usually from November through early August). The run year is generally divided into three scheduling periods. The deadline to submit requests is several months in advance of each scheduling period. We encourage users to 'bookmark' the deadlines page and set a reminder for these annual deadlines in their calendars.


Step 2: Submit beam time requests.

Once a proposal is peer reviewed/rated, the next step is for the proposal spokesperson (or their authorized lead contact) to request beam time by the posted deadlines for each scheduling period in which he/she is interested in running their experiment(s). Generally standard proposals are eligible to request beam time for up to six scheduling periods over a two-year period. This separate step provides a mechanism for the proposal spokesperson to request their desired beam line(s), amount of beam time, specific equipment or beam line configurations, and dates when they are available (or indicate preferences or when they have conflicts).

Submit separate requests through the user portal by the posted deadline for each beam line and each allocation, technique or equipment configuration desired.

Review deadlines posted on the SSRL Deadlines website, user portal and subscribe to the SSRL newsletter to stay informed about news, events and upcoming deadlines at SSRL.


SSRL Beam Line Schedule Information:  Scheduling for SSRL beam time is centrally managed and coordinated by the User Research Administration (URA) Office to ensure optimal utilization of SSRL beam lines.

URA and beam line staff review beam time requests for each beam line, technique and time period desired. Priority is given to highly rated proposals, while also considering the amount of beam time that has previously been allocated as well as the proposal team's demonstrated productivity (through publications, patents, awards, etc.). Consideration may also be given to graduate students who need a small amount of beam time to complete their thesis work.

Other important criteria considered in developing the beam line schedule includes availability of desired equipment and availability of beam line staff to prepare for user experiments. Experiments with similar equipment configuration set ups are scheduled together whenever feasible for maximum efficiency and to minimize downtime. URA staff work with beam line scientists and engineers to develop a schedule that ensures the availability of desired resources to meet the needs of the proposal team and the faciity.

A rating of ~1.4 is generally the initial cut off for beam time on most oversubscribed SSRL beam lines. Additional requests are kept in the queue and may be accommodated to fill cancelled beam time.

Note: During the beam time scheduling process if members of the same research team have multiple proposals and submit multiple beam time requests, they will not likely be granted beam time for each of the proposals in each scheduling period. Most SSRL beam lines are significantly oversubscribed by proposals with high scientific merit; consequently, requests for highly oversubscribed beam lines will likely be limited to one experiment per research group per run year.


Step 3:  Review SPEAR and beam line schedules

 Review the SPEAR operating schedule and the beam line schedules which are posted online and made available to Proposal Spokesperson and Lead Contacts through for the User Portal. See Step 4 below to ACCEPT beam time assignments and SUBMIT SUPPORT REQUESTS.


Step 4ACCEPT beam time and SUBMIT SUPPORT REQUEST listing experiment participants

As early as possible, preferably at least 30 days before scheduled beam time, the proposal spokesperson or their authorized lead contact must complete the following steps to accept to confirm allocated beam time. Then submit the support request to inform SSRL of all users who plan to participate in beam time, either onsite or remotely. Beam time may be canceled and re-allocated to another user group if this step is not completed 30 days in advance.

  • Log in to the User Portal (request a password if needed; note this is different from the SSRL or SLAC password).
  • From the top blue navigation bar, select "Support Request/SSRL Support Request" to view beam time allocations for active proposals. Select "Accept Time" to acknowledge the beam time allocation. To cancel assigned time, click "Decline Time" and enter relevant comments as prompted. (Also contact URA directly to discuss if rescheduling options might be available.)
  • Select "Enter Request". If the spokesperson will not be present to provide oversight during the experiment, identify a 'Lead Contact' to supervise this experiment. Inform us of everyone who will be participate in this scheduled beam time. 'Remove' colleagues who will not participate in this experiment, and 'Add' other collaborators as appropriate. Any new users are required to register through the user portal 30 days in advance and complete safety training before arrival.
  • Review the beam time request summary and inform us immediately if the experimental plans/equipment/safety needs have changed to determine whether thelate changes can be accommodated.
  • Scroll down and indicate support needs (mono calibration edge), lab access, vacuum, computers, water cooling requests, etc.
  • Select "Submit".

User Registration & Assistance

  • Each individual user affiliated with a scheduled proposal is required to register (and annually verify their personal information is accurate).
  • See procedures for foreign users.
  • Complete on-line safety training BEFORE TRAVELING TO SLAC
  • Plan to arrive before 1 pm to complete check-in at the SLAC Security Badging Office/VUE Center and receive an ID badge and proximity access.


Step 5:  Review User 'To Do' List

As soon as beam time is assigned, review and complete the user 'To Do' list.

See other helpful information related to SSRL beam time.

SSRL staff are dedicated to providing outstanding user support and work hard to ensure that user beam time and experiments are successful. Contact URA, SSRL scientists, engineers, beam line operations staff  to answer any questions or to provide assistance.

We welcome your feedback, and we look forward to your visit to SSRL!



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