We were discussing today (Bogdan, Marek, Piotr and myself) the horns
support structure and we clearly need some more info on the following
topics:

-) How is the stripline connection designed in the RAL version of the
supporting system and how is the alignement of horns achieved? Is the
individual alignement of each horn included? Does the electrical
connection pass through some sort of feedthrough in the vessel?
-) We think that the necessary precision of alignement might play a
crucial role in the design of the support system. In particular, it would
be useful to define the admissible misalignement of horn axis w.r.t. the
beam orbit/trajectory in terms of translation and tilt in the vertical and
in the horizontal planes. Some sort of error analysis related to possible
systematic and random errors should be carried out.
-) Based on the error analysis the horn adjustement system should be
defined, as a function of the required precision. In addition, the
position of fiducial(s) on the horn supporting structure (outside the
vessel) should be specified (for the alignement and realignement purpose).
-) During the previous meeting the "packed bed" concept of target has been
confirmed. Is the integration of the "packed bed" target in the horn ready
or shall we work it out? If the integration of packed bed target is
defined we need some more info about target-horn layout and positioning
precision. I guess, C. Densham might have some more information on this
issue.
-) Currently, we are working out the concept of double frame support for
4-horns assembly, when compared to the single frame design presented
during the previous meeting. We think, this might be our contribution for
the next meeting. The presentation on "Double frame versus single frame
horns support concept" will be given by Bogdan Szybinski. Piotr is
planning to carry out the related dynamic analysis.
-) For what concerns the horn irradiation and the lifetime prediction we
would need some more info about the "dpa" distribution along the
cylindrical part of the horn structure (close to the target).

We hope, you might help us to get some more information needed for further
work.

Best regards,

Blazej
(on behalf of Cracow team)