Beams
FRIB offers fast, stopped, and reaccelerated rare-isotope beams from the FRIB linear accelerator (linac). Rare-isotope beams are produced from a primary beam that impinges on a target. In addition, FRIB offers 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).
Primary beams will be added as needed to meet user demands. Planned additions based on user rare isotope beam needs are listed as being developed next.
FRIB primary beams
Demonstrated and available (updated 7 April 2025)
Please note: the best effort will be made to use the full primary beam current on the FRIB target. However, the full beam intensity may not be able to be used for all experiments due to potential limitations arising in the final optimized setting. FRIB is planning to demonstrate higher beam currents for selected primary beams which will then become available.
| Isotope | Energy (MeV/u) | Beam current on FRIB target (pnA)* |
| 18O | 160 | 7813 |
| 22Ne | 170 | 5348 |
| 22Ne | 290 | 784 |
| 28Si | 250 | 1429 |
| 28Si | 300 | 1190 |
| 36Ar | 200 | 2778 |
| 36Ar | 300 | 926 |
| 40Ar | 200 | 2500 |
| 40Ar | 255 | 1961 |
| 48Ca | 232 | 1796 |
| 48Ca | 240 | 1215 |
| 58Ni | 250 | 1379 |
| 64Zn | 200 | 782 |
| 64Zn | 250 | 780 |
| 70Zn | 200 | 782 |
| 70Zn | 230 | 780 |
| 78Kr | 247 | 1038 |
| 86Kr | 228 | 1020 |
| 82Se | 227 | 1074 |
| 124Xe | 228 | 707 |
| 198Pt | 188 | 184 |
| 209Bi | 188 | 255 |
| 238U | 177 | 475 |
*pps = pnA x 6.25 x 109
pps = particles per second
pnA = particle nanoampere
Being developed next
| Isotope | Energy (MeV/u) |
| 64Ni | 235 |
| 70Ge | 246 |
| 92Mo | 238 |
| 144Sm | 215 |
Rare isotope beam rates
Rare isotope beam rates used in proposals must be calculated by an FRIB beam scientist.
An approximate estimate 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 (PDF)
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 availability of material at the time of the experiment. Beams that are not on the beam list may be requested in discussion with the stopped and reaccelerated beam operations department.