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.
We plan to submit a proposal to DOE in 2007 and hope to complete the project
- 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
- 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.
At the bottom of this page you will find interactive charts (svg format)
on expected beam rates
out of the ion source
after acceleration in the tandem.
Possible electron drivers
Fig. 1 -
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.
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.