[asac]Draft of ASAC Report: section on 3-way project

[Pierre.Cox at ias.u-psud.fr]

Dear All:

Please find hereafter a draft of the section
'Toward a three-way Project' which was missing
in the draft report of the ASAC face-to-face meeting
report. Comments welcome. 

Best regards,

Pierre


\section{Toward a three-way Project} \label{3way}

The enhancements to the ALMA Project resulting from a participation
of Japan in the Project are so valuable from a scientific point of
view that all efforts should be made to allow Japan to become a
full partner in a future 3-way ALMA Project.  These enhancements
include the ACA, the missing six receiver bands, and the Second
Generation  Correlator.  In addition, the experience
of the Japanese community, in particular with ASTE, will be a
valuable asset to ALMA.  During the meeting, M. Ishiguro presented
areas of Japanese interest in ALMA, which include: Antennae,
frontends for Bands 10 and 4, the photonic LO system, a High
Speed Sampler, the Second Generation Correlator together with
a contribution to the infrastructure and computing.

The ASAC notes that in order to make an extension to a three-way
partnership possible, a certain flexibility needs to be kept in
the Project, since Japan cannot be counted on to provide all the
enhancements.  Receiver Band 1, for example, would work with
HEMT amplifiers for which there is no real expertise in Japan
and the Second Generation Correlator has been envisioned as a
European-Japanese collaboration. All decisions which are not
time critical, i.e. which do not lead to a delay in the two-way
project, should be postponed until the situation of Japan is clear.
In particular, a single antenna type is of prime importance 
for the overall performance of the array, and we emphasize 
that the selection process should be based on the evaluation 
of all three prototypes, provided the current schedule is kept.
We refer to the recommendation for a single antenna type in
the antenna section of this document.