FRIB primary beams

Being developed for PAC4 Epoch3a call for proposals 
(updated 1 June 2026)

The beam list defines the isotopes and their maximum beam intensity for the primary beam that the FRIB linac can deliver on target. These intensities cannot be achieved for all requested rare isotope beams, specifically for rare isotope beams of rigidity close to the primary beams when the primary beam intensity will be limited to values significantly below the listed value. 

*pps = pnA x 6.25 x 10⁹
pps = particles per second
pnA = particle nanoampere

Rare isotope beam rates

Rare isotope beam rates used in proposals must be calculated by an FRIB beam scientist. 

An approximate estimate for PAC4 can be obtained from the calculator. The estimates available on the web-based calculator assume optimal conditions and are only intended to provide a rough indication of experiment feasibility. Actual rates will likely be less. Rates above 1E8 pps will require a detailed evaluation of primary beam and fragment power deposition and may not be possible.

For further information on how rates are calculated, please review this tutorial: LISE++ tutorial: Making 64Cr

Demonstrated and available (updated 29 May 2026)

*pps = pnA x 6.25 x 10⁹
pps = particles per second
pnA = particle nanoampere

Beam list for stand-alone operation at ReA3, ReA6, or Stopped Beam Area

The PDF list below includes stable and long-lived radioactive beams that may be run at ReA3, ReA6, or the stopped beam area in stand-alone mode (that is, not coupled to the FRIB linac).

Please note that beams of long-lived and rare stable isotopes are subject to proven extraction from the ion source and availability of material at the time of the experiment.

ReA3, ReA6, stopped beam area list of beams