Access Process

2. Submit Beam Time Requests

Once a proposal is peer reviewed/rated (assuming the rating is sufficiently high to successful compete for beam time), the next step is for the proposal spokesperson (or their authorized lead contact) to submit beam time requests by the posted deadlines for each scheduling period in which the team is interested in running their experiment(s).

Deadlines

• X-ray / VUV
  • August 1
  • November 1
  • March 1
• Macromolecular Crystallography
  • September 7
  • January 19
  • April 24

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).

This step needs to be repeated for each of the three scheduling periods per year in which the proposal team would like to access SSRL's capabilities. Unscheduled Beam Time Requests do not roll over to the next scheduling period. For more information on scheduling periods, visit the Schedule Website.

How to submit a Beam Time Request:

• Please log in to the User Portal (request a password if needed; note this is different from the SSRL or SLAC password, beam line accounts, Windows, and safety training)
• In the User Portal, click the "SSRL" tab
• Then click "Beam Time Requests" to view active proposals and previous beam time requests.
• Click on "New Request" and follow the instructions to request beam time for your active proposals
  • Use the XRAY form to request BL 1-5, 2-1,2-3, 4-1, 4-2, 4-3, 6-2, 7-3, 9-3, 10-2, 11-3, 14-3, 15-2, 17-2
  • Use the VUV form to request BL5-2/4, 8-2, 10-1, 13-2, 13-3, 16-2
  • Use the PX form to request BL9-2, 12-1, 12-2, 14-1

Submit separate requests through the User Portal by the posted deadlines for each beam line and each allocation, technique or equipment configuration desired.

How to modify/change Beam Time Requests

To view status or modify recently submitted requests in the User Portal, click on the '(+) view beam time requests' link located below the proposal title. Requests that have been submitted but not yet received by the user office can be un-submitted (withdrawn). Draft requests can be saved to be edited, completed later, or deleted.

To change the list of users expected to participate for each experiment, click on 'Update' for the corresponding scheduled beam time.

Beam Time Scheduling Considerations

User Services and beam line staff review beam time requests for each beam line, technique and time period desired.

Many factors are considered in scheduling SSRL beam lines. Scheduling 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. Consideration may also be given to graduate students who need a small amount of beam time to complete their thesis work. 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 as beam time becomes available to fill canceled beam time.

Other important criteria considered in developing the beam line schedule includes availability of resources (equipment, beam line staff, etc.). Experiments with similar equipment configuration are scheduled together whenever feasible for maximum efficiency and to minimize downtime. The User Services Office works 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 facility.

Although users can request beam time on multiple SSRL beam lines over several scheduling periods, note the following:

Many SSRL beam lines are oversubscribed by proposals with high scientific merit; consequently, requests for highly oversubscribed beam lines will likely be limited to one (in rare cases two) experiments per research group per run year.

User Portal