Initiatives - HRIBF Electron Driver
A Preliminary Design Study

Initiatives - HRIBF Electron Driver
One method to enhance the intensity of very neutron-rich RIBs is to use photofission instead of proton-induced fission. The lower excitation produced by Bremsstrahlung (from electrons) results in fission products with less neutron emission. Calculations suggest that isotopes such as 132Sn could be enhanced by 2 orders of magnitude over our present-day yields from ORIC's proton-induced fission.
  • Bremsstrahlung from the electron beam induces photo-fission in a uranium carbide target system with a thickness of ~35 g/cm2
  • A 50 kW, 100 MeV electron beam incident on such a target would generate a total uranium fission rate of 1013 fissions per second as compared with 3x1011 at the ORIC-driven HRIBF.
  • a 50 kW beam will deposit approximately 10 kW in our target with the same energy density that we presently have.
  • The new targets are only 2 times larger in diameter and approximately 50% longer. We believe no new target R&D is necessary to achieve the rates listed in the links below.
  • The mass distribution peaks approximately 2 neutrons more than proton-induced fission.
  • Our 132Sn yields should be a factor of 500 higher.
  • This electron-driver initiative could provide extremely high neutron-rich RIB yields at a much lower cost than hadron drivers.
  • a turn-key electron machine can be purchased which delivers 100 kW electron beam.
  • Studies are underway with the Oak Ridge Electron Linear Accelerator (ORELA) to further explore the feasibility of using high power electron beams to produce n-rich RIBs, and to experimentally determine RIB yields.
We plan to submit a proposal to DOE in 2007 and hope to complete the project in 2012.

More information

At the bottom of this page you will find interactive charts (svg format) on expected beam rates out of the ion source and after acceleration in the tandem.

Possible electron drivers

Fig. 1 - Rhodotron from IBA
Several different types of "turn-key" electron machines are available today. A rhodotron from IBA is appealing due to its small size which could possibly fit within the existing facility although some construction might be necessary as one scheme requires the machine to be elevated above the target. LINACs have been around for years and have proven reliable, efficient machines capable of running many years. One possible LINAC solution is shown below; this Accel LINAC is located at the Paul Scherrer Institut in Switzerland.

Fig. 2 - Electron LINAC from Accel

The size of this project is well over 5 M dollars and is restricted to improving only those neutron-rich beams produced by fission. This project could begin as early as FY09 and would be a turn-key operation. If this project is funded, we would balance this project and the ORIC axial injection project in order to minimize down time.

Interactive charts

These charts are in svg format and use java script. Most browsers are developing svg capabilities and/or rely on a free Adobe SVG Viewer plugin.

The information on this page may contain dated material as this project develops. Contact the HRIBF User Liaison if you need the latest information.

For questions about this page please contact the HRIBF User Liaison.

This file last modified Thursday March 01, 2007