Radiation Safety

In Phy 445/515 students who choose to do experiments in the CASE Nuclear Structure Lab will be handling radioactive materials (RAM, such as sealed test sources and products of irradiation) and operating x-ray producing equipment. They will be doing so "under the tutelage" of professors, staff and teaching assistants who are Authorized Users under the license of the CASE NSL and Department of Physics and Astronomy. Therefore, it is not necessary that the Phy 445/515 students complete the course to become an Authorized User themselves.

However, it is always best to understand the risks and issues involved. For general information, here are some good sources:

• The Phy 445/515 course site on Blackboard has a primer on Radiation Safety
• The Stony Brook University department of Environmental Health and Safety has a Radiation Protection Services group.
• The Brookhaven National Lab (BNL) National Synchrotron Light Source (NSLS) Training Site has links to the BNL rad worker study guides

CASE NSL Specific Info

Our concern is to keep your exposure to ionizing radiation AS Low As Reasonably Achievable (ALARA). This is the policy of the University, of BNL, of CASE and of most institutions using RAM for research. This goes beyond estimating risk: even if we expect no significant risk to you the policy to make exposures ALARA means that weak sources are still stored behind shielding and people are excluded from areas with beam. Any reasonable step that can reduce exposure is worth the effort, as policy and as good lab practice.

• Radiation Producing Equipment
  • Van de Graaff

The FN Tandem Van de Graaff accelerates heavy ion beams with a potential of several million Volts. There is the possibility that electrons may be accelerated within the beam pipe, which would create x-rays when stopped. X-ray monitors on the Tandem warn the user if this condition arises.

• • Injector Ion Source

The ion source 'deck' or 'table' is held at a negative voltage of 100-200 kVolts. Electrons accelerated with the beam can create large (but very forward focused) sources of x-rays. X-ray monitors on the beam pipe warn the user if this condition arises

• • Beam Path

After acceleration by the Tandem the heavy ion beam can induce reactions on apertures or other devices within the beampipe. One should avoid the 'object' or 'image' slits when beam is in use.

• Radioactive Materials (RAM)
  • Test Sources

All of the test sources used in the CASE NSL are very weak and only useful for detector testing. Nontheless, one should handle them carefully and store them behind shielding when possible.

• • Beam Stops! Includes Target

The beam stop, including the target, may be activated by the beam, that is, species may be created with half-lives long enough that they are still active when people enter the Target Room. One should limit exposure to the beam stops with Time, Distance and Shielding.

• Simple Rules:
  • Don’t Enter Van de Graaff Vault if Ion Source is On (loud!)or if BEAM ON
  • Don’t Enter Target Room if it is locked (… N.S.S.)
  • Don’t handle RAM unless directed by Staff
  • Four Principles: Time, Distance, Shielding

Return to Lab Manuals