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RA5. Suggestions Welcome for New Beam Development
HRIBF welcomes suggestions for future radioactive beam development. Such
suggestions may take the form of a Letter of Intent or an e-mail to the
Liaison Officer at
grosscj@ornl.gov.
In any case, a brief description of the physics to be addressed with
the proposed beam should be included. Of course, any ideas on specific
target material, production rates, and/or the chemistry involved are also
welcome but not necessary. In many cases, we should have some idea of the
scope of the problems involved.
Beam suggestions should be within the relevant facility
parameters/capabilities listed below.
- The tandem accelerates negative ions only.
- Positive ions may be charge-exchanged or used directly off the
platform (E < 40 keV).
- ORIC presently produces
up to 52 MeV of 1H (12 uA);
49-MeV 2H (12 uA);
120-MeV 3He (not yet attempted, costly);
100-MeV 4He (3 uA).
Higher currents may be possible.
- Typical reactions required to produce more than
106 ions per second are n, 2n, pn, and
alpha-n fusion-evaporation reaction channels and beam-induced fission
products. More exotic reactions are possible if extremely low beam
currents are all that is needed.
- Species release is strongly related to the chemistry between the
target material and the beam species. It is best when the properties
are different and the target is refractory. Thin, robust targets
(fibrous, liquid metals, a few grams per square centimeter) must be
able to withstand 1500 degrees Celsius or more.
- Minimum half-life is seconds unless chemistry is very favorable.
- Very long-lived species (T1/2 > 1 h)
are probably best done in batchmode, i.e., radioactive species are
produced with ORIC beams and then transported to the ion source where
beams are produced via sputtering. Sputter rates of the species
and target substrates are important.
- Isobaric separation is possible for light beams (fully stripped ions),
while isobaric enhancement may be possible for heavy beams.
- Beware of long-lived daughters or contaminant reaction channels.
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