Table of Contents

Experiment policies

Beamtime shifts schedule

Unless informed otherwise by the beamline support staff, the beamtime starts at noon of the first day allocated to the experiment and end at 8:00 am of the last day; an exception to this rule are the first day of Accelerator Physics and Accelerator Maintenance, when the beamtime usually ends at 6 am. Accelerator shifts are usually scheduled on Monday and Tuesday every two weeks, and are indicated in the schedules. Also, shorter shifts are sometimes scheduled on BL12-2, with different starting and finishing times. You will be informed by staff about unusual starting and finishing times.

User responsibilities

Both on-site and remote users are responsible for:

  • Ensuring that one experimenter who has attended the beamline orientation participates in the experiment at all times.
  • Contacting SSRL staff in case of a problem.
  • Backing up data before their run has ended (users transferring data should log onto the SMB computer smbcopy for this purpose).
  • Reporting missing or malfunctioning equipment.
  • Protecting the SSRL computers from unauthorized access by logging out or locking the terminal screen whenever not using them.

Users collecting data on-site are also responsible for the following:

  • Reading and complying with the policies regarding use of liquid nitrogen or other hazards associated with the particular experiment.
  • Knowing and following all applicable safety protocols.
  • Posting the proper safety protocols and signs required for their experiment.
  • Cleaning up the beamline and lab areas before their run has ended.

On site users should not attempt:

  • Making repairs or realigning beamline optics.
  • Removing covers or unplugging detectors and other electrical equipment.
  • Rebooting computers.
  • Using SSRL computers other than those provided at the assigned beamline.

Contacting SSRL staff

Before your Experiment

During your experiment

  • For any problems, contact support staff by phone. Use the cell phone table found in the user support schedule to look up the cell phone number associated with your beam line.
  • Outside of normal working hours please email your user support. If the support person has become unavailable, send a text to the "After Hours Support Pool" phone number: 1 209 730 6640. Please indicate the beamline and a brief description of the problem. (If you resolve the problem before a response, text back that you no longer need help.) Texts sent to this number outside of normal working hours are voluntarily monitored by a larger pool of staff, thereby increasing the odds of receiving help before the next day.
  • For questions about SPEAR3 status call the Duty Operator at 650-926-4040 or visit here.
  • For sample container exchanges and other support that requires staff to be on-site:
    • For weekdays, arrangements can be made with the assigned user support staff for cassette exchanges during normal working hours.
    • For weekends and holidays, support staff will set the cassette exchange time.

Important: Note that there is no beamline support staff on site during the weekend or outside normal working hours; issues that require staff being present at SSRL at these times will be dealt with at the staff's earliest convenience.

Off-line use of computer resources

  • No restrictions.

Use of the SAM robot for sorting samples between cassettes and/or unipucks

Blu-Ice provides an interface for moving samples between cassettes and/or uni-pucks. This facility is available to SSRL users during their scheduled beamtime. The following policies apply:

  • Sample sorting is considered to be part of the experiment and should be completed by the end of the scheduled beamtime.
  • This service is not available during beamline maintenance periods, accelerator physics or SPEAR3 shutdowns.
  • All the SSRL cassettes or unipucks used to move samples must be supplied by the user, and mounted on the beamline robot dewar at the start of the experiment or during normal working hours.
  • Staff may not be called at off hours or on weekends to load a cassette in the dewar for sample sorting.


Biohazardous materials include infectious agents and hazardous biological materials as described by the United States Department of Health and Human Services, Centers for Disease Control for infections agents and by the National Institutes of Health for recombinant DNA molecules.

All experiments involving biohazardous materials must be clearly identified and categorized according to their biosafety level and carried out according to the guidelines set by Stanford University Currently, the following restrictions apply for biohazardous samples:

  • Level 1: No restrictions
  • Level 2: Users will be requested to submit a form for review by the Stanford University Administrative Panel on Biosafety, which will communicate any special controls or requirements to the user. Users must adhere to the approved protocol and notify the safety officer/safety coordinator before making any changes.
  • Levels 3 and 4: Due to the levels of engineering and administrative controls needed for biosafety level 3 and 4 hazards, use of these agents is currently not permitted at SSRL.

On-site handling of samples

These policies must be followed by users bringing their samples to SSRL. We recommend that remote users follow the same or similar safety protocols when applicable.

Liquid nitrogen use

This section describes hazards and proper handling procedures for work with liquid nitrogen

Skin and eye frostbite burns

Direct contact with liquid nitrogen, metal or other material that is in contact with liquid nitrogen or cold nitrogen gas can cause freezing of exposed tissue.

  • Follow all documented procedures for a given task and any additional instructions that may be posted at the work site.

  • Wear the appropriate Personal Protection Equipment (PPE) appropriate for the task.

Table 1: Required PPE for handling Liquid Nitrogen
Safety Glasses Cryogenic Gloves Goggles or Face Shield Long Pants without cuffs or Apron Closed-toe shoes Insulated tool handles
Fill dewar with close-loop transfer line X X
Fill dewar with open flow delivery line X X X X
Dewar to dewar transfer X X X X
Removing/storing items in dewars X X X X
Transporting open dewars holding less than 0.5 L X X
Disposing of liquid nitrogen by pouring on ground X X X X
Disposing of liquid nitrogen by bubbling warm nitrogen gas X X
Manipulating protein crystals in dewars X X
Transporting dewars or tanks with lids or closed valves
Disposing of liquid nitrogen by evaporation


In confined areas, there is a risk of asphyxiation by displacement of oxygen. Do not use liquid nitrogen in a confined space unless the maximum allowable amount of liquid nitrogen has been posted by the SSRL Safety Officer or if the room is equipped with an oxygen deficiency (OD) alarm.

  • All experiment hutches are equipped with OD alarms. Immediately exit the hutch if the alarm sounds. If the OD alarm sounds when you are outside the hutch, do not enter the hutch.Do not open the door until the alarm has stopped.

  • The experimental floor is also equipped with oxygen alarms, which can activate if, e.g. a liquid nitrogen line ruptures or leaks. If the experimental floor OD alarm sounds, treat it like am emergency alarm: exit the building through the nearest exit and do not re-enter until the duty operator indicates that it is safe to do so.

  • Cold rooms in general are not equipped with OD alarms. Do not exceed the posted amount of liquid nitrogen allowable in the confined space. If there is no posting, do not bring liquid nitrogen into the confined space.

Instructions for liquid nitrogen disposal

  • Use a warm nitrogen bubbler to evaporate liquid nitrogen when possible.

  • Small amounts of liquid nitrogen (less than 0.5 Liters) can be poured carefully in an open area on the floor.

  • Larger amounts must be poured in an open area outside the building.

Compressed gas experiments

The following policies apply for work at the SSRL involving gases delivered in compressed gas cylinders (CGC):

  • Requests to work with CGC must be indicated the Beam Time Request Form (typically submitted three times per year). To make a request after the form has been submitted, contact the SSRL User Office.

  • Standard instructions and safety protocols are to be applied when using the SSRL pressurization cells:

    1. The SSRL pressure cells may only be used as specified in the instructions.

    2. The CGC must be secured at all times during the experiment.

    3. Only support staff are allowed to replace an empty CGC.

  • The following experiments require specific safety protocols to be developed by SSRL staff; this requires at least a 1 month lead time before the beam time:

    1. Experiments using CGC directly purchased and shipped by the user.

    2. Experiments involving flammable, toxic or corrosive gases (e.g. O2, CO).

    3. Experiments involving gases conducted in the cold room or other confined space.

    For case 2 and 3, complete the Hazards From available from the User Research Administration Database is required for cases 2 and 3.

  • Xenon and Krypton CGC are supplied by the SSRL SMB group. Other gases may be purchased through SSRL by filling the specialty gas purchase form. Setting up an SSRL account is required for purchasing items through the SSRL.