ThorEA - Towards an Alternative Nuclear Future.pdf

Q11. ThorEA focus upon FFAG technology. If we remove the synchrotron concept from the list of other potential ADSR
accelerator technologies because of its pulsed nature, then the only two remaining are SCRF linacs and cyclotrons
(or their combination). An SCRF linac concept has already received wide international attention. It was the basis
for Rubbia’s original proposal may be the most feasible concept to date. In this respect is the optimism regarding
the feasibility of the ns-FFAG concept with regard to the ADSR applications really warranted?
A11. This comparison with alternative accelerator types is relevant but the conclusions can be challenged. As of today,
the linac is the simplest solution, but because of cost and size it may not be the best for ADSRs and hence other options
must be investigated. Superconducting RF technology is also an attractive solution that could be appropriate for any ADSR
accelerator driver, and may or may not turn out to be inappropriate for FFAG accelerators. That is why the evaluation of
accelerator driver technology lies at the very core of the proposed R&D programme, and is the principal challenge of the
ThorEA study. We therefore feel it is unreasonable at this stage to expect a detailed answer to the questions raised. Indeed
if those answers existed then an ADSR would undoubtedly already have been built. The ThorEA report, rather than focusing
upon FFAG technology, emphasizes the optioneering and feasibility aspects of the proposed programme within which all
relevant accelerator technologies will be evaluated, not against FFAG technology but alongside it.
Q12. Will not a crucial factor in the ADSR design be the minimization of beam losses to reduce component radio-activation
and enable hands-on maintenance?
A12. There is no doubt that for all types of accelerators, special care has to be taken to control beam loss and try to restrict
it to certain, planned, places. In the case of linacs, a lot of beam loss can occur when the beam is first bent, which tends
to be at high energy, where it can be particularly damaging. This is a problem that is present in all accelerator driven
facilities and installations and is one that will have to be addressed as part of the proposed R&D programme. There is
no indication as yet that it will be either better or worse for an ADSR driver.
Q13. The spend profile jumps from 0 to £40m in the first year, and fluctuates from £53m to £90m and back to £60m in
years 3, 4 and 5. Surely these features are unrealistic?
A13. ThorEA believes that the proposed spend profile is realistic. The £40m step function in year one is not unmanageable.
The assembly of LOKI requires significant up-front investment in existing accelerator technology. It is also important to
point out that it intended that in the report we suggest that it will be advantageous to locate the project at the Daresbury
Laboratory, where technical and managerial accelerator expertise, and the appropriate physical infrastructures capable of
coping with a project of this magnitude already exist.
A report prepared by: the thorium energy amplifier association 69