Radiation Safety at ATLAS


For onsite emergencies, call 911 on the internal phones
(or 630-252-1911 on cell phones)

SafetyAspects of radiation safety at ATLAS:

  • Health Physics Coverage at ATLAS is provided by Argonne National Laboratory. Health Physics personnel must be notified if there is a possible contamination incident, or if target and/or detectors are to be removed from a beam line following an experiment. HP Contact information:


    • William Hinton (HP Technician): 2-9179 (4-9179 pager)
    • Jonathan Nading (HP Technician): 2-9179
    • Merlin Ngachin (Principal HP): 2-2668 (4-5722 Pager)
    • John Vacca (Alternate HP): 2-6180 (4-1978 pager, 630-327-9266 cell phone)


  • ATLAS requires that a thermolescent dosimeter (TLD) badge be worn at all times when within the facility.
  • ARIS is the ATLAS Radiation Interlock System. It serves as an active monitor of radiation levels in the experimental and accelerator areas. ARIS also provides a mechanism to allow personnel into areas where beam may be present as long as the measured dose rate remains below 5 mrem/hr and the 8-hour integrated dose is less than 10 mrem in the monitored experimental area. Similarly, accelerator areas may be occupied as long as the dose rates are less than 9 mrem/hr and the 8-hour integrated dose is less than 10 mrem.

  • Use of radioactive sources at ATLAS depends on the type of source. The types of sources used at ATLAS are divided into two main catagories, sealed and open, and are typically used for calibration purposes.

    Sealed sources are mainly used for calibrating gamma-ray detectors and are kept in safes in the experimental hall. Personnel who have completed the ATLAS Site-specific training and Radiation Worker I equivalent training are allowed to use sealed sources. A thermoluminescent dosimeter (TLD) badge must be worn when using these sources and they must be signed out prior to use.

    Open sources are typically used to calibrate charged-particle detectors. The use of these sources is more restrictive. Since there is the possibility of the spread of radioactive material, more precautions are needed. Only Physics Division personnel who have completed the annual Open Source training, Rad Worker II and Rad Worker II practical training are allowed to handle open sources. Furthermore, Health Physics personnel may also need to be present, depending on the strength and isotope used.

    Other sources that are occasionally used at ATLAS are Cf-252 fission sources (open and sealed), and neutron sources (Pu-Be and Pu-C13). Since these sources contain Special Nuclear Materials (SNM), their use is restricted to Physics Division personnel.

    More information on the use of radioactive sources at ATLAS may be found in the ATLAS Site-specific training and Radiation Worker I equivalent training.


  • Outside Radioactive Material to be used at ATLAS needs to be brought in through our Special Materials representative. This includes calibration sources, radioactive targets, and any other radioactive materials. Please contact the ATLAS User Liaison ([email protected]) if you need to bring radioactive material to ATLAS.


  • Removal of Equipment used in an experimental area, if it may have been contaminated or activated by exposure to beam and/or open sources, can only be done AFTER it has been surveyed by Health Physics personnel. This would typically apply to targets, beam line components, and detectors used inside vacuum enclosures.  Also, EVERYTHING  that was in a beamline must be surveyed before it is removed from the experimental area.  However, it is important to be sure that any other items used in experimental areas have not been activated prior to removal. Please contact the ATLAS User Liaison Physicist (Shaofei Zhu), the ATLAS User Administrative Assistant (Barbara Weller) or any of the Health Physics personnel listed above before removing equipment from experimental areas.