Life Sciences Collaborative Access Team

9700 S. Cass Ave, Bldg 436A
Argonne, IL 60439
Main Office:    630-252-0222
21-ID-D:    630-343-6851 21-ID-E:    630-343-6852
21-ID-F:    630-343-6853 21-ID-G:    630-343-6854

General Users at the APS and LS-CAT

LS-CAT provides beamtime to general users through the APS General User Program. This time is available free of charge* through a competitive proposal process. Allocations are made three times a year. Is your need urgent? Rapid Access time is also available free of charge*. Just submit a normal APS General User Proposal with Rapid Access beamtime request.

APS General User time, including Rapid Access beamtime requests, are available to both academic and industrial users.

Proposals with Rapid Access Requests

This process takes much less time to arrange than the normal process:
  1. Find a facility that has time around when you need it. (here to see LS-CAT available slots.) Save yourself some grief and call and/or email the person in charge of scheduling and see if there is a slot available for rapid access.
  2. Submit a normal proposal (see below) but with a Rapid Access Beamtime Request. You'll find this in the "Beamtime Request" tab of the proposal: click on the "For which scheduling period are you applying?" drop down box. Chose the period marked "(RAPID ACCESS ONLY)".
  3. On the "Choice Of Beamline" line be sure the beamline you contacted in the first step is listed FIRST. They will not be able to schedule your time otherwise.
  4. Your proposal will still be reviewed and in times of high demand you may lose out if someone else wants the same slot and has a proposal with a better rating. However, you do not have to wait for the Proposal Review Panel or the Beamtime Allocation Committee to meet before your time can be assigned.

Proposals with Normal Beamtime Requests

The calendar for APS General User Proposals can be found here. You can refer to this table for the following explanation of the process:

  1. You submit a proposal by the "Proposal Deadline" date. Part of the proposal is the Beamtime Request. During the 2 years your proposal is valid you may make many beamtime requests, up to a maximum number of 8 hour shifts assigned by the Proposal Review Panel (see the next step). Here are some pointers:
    • Be sure to request enough time to cover your needs for 2 years. Be realistic: the reviewers know what it takes to collect data at the APS and understand the complexity of the project you propose to work on.
    • Do not request MAD data collection at a fixed wavelength station. It wont work but it will cause a 1 to 2 week delay while the BAC tries to figure you what you want.
    • The APS uses units of 8 hours shifts: 3 shifts per day.
    • Beamlines (including LS-CAT) schedule beamtime in units of days. That is, you should request time in multiples of 3 shifts. Note that some facilities require that you schedule a minimum of 6 shifts (2 days). LS-CAT allows General Users to schedule time in blocks of 1 day.
    • A "day" at the APS can range anywhere from 14 hours to 25 hours depending on the details of the schedule. Be sure to ask if this is important to you.
    • The beamtime request section of the General User Proposal has a place to indicate when you cannot accept beamtime. Please take the time to fill this out. If you do not want to come to the APS during your homecoming game, put it down. Although there is no guarantee your blackout date can be honored, you will be expected to accept (without complaint) any date that is not listed.
  2. The Proposal Review Panel (PRP on the calendar) meets and assigns a score for the proposal: 1 is best (and very rare) while 5 has the lowest priority. While the scoring system is not perfect, it does a reasonable job of ranking most proposals. The biggest mistake people make that leads to poor scores is the omission of details in the proposal.
  3. The Beamtime Allocation Committee (labeled BAC on the calendar) meets and assigns the proposal to a particular beamline. This is where you can expect problems if you requested time at a station that cannot accommodate your experiment.
  4. The facility where you have been assigned will contact you to schedule your time.

*The APS charges proprietary usage fees when applicable.

The APS is currently in the midst of beamline upgrades. In the interim, LS-CAT currently provides data collection services in coordination with other beamlines. Please refer to the "Dark Period Data Collection Dates" on the main page for details.