At the April 1999 Science
Council meeting, the magnetism college chairman (R. Cywinski) in his report gave an order of priority for the
Millenium programme, with first priority going to super-D2B, followed closely
by D3-polarimetry. He wrote The subcommittee expressed its strongest
support for the super-D2B high-resolution diffractometer upgrade... the
principal advantage of the proposed order of magnitude increase in intensity
would not be that more experiments could be performed, but that new science
would ensue. He referred to charge
density ordering, incommensurate and complex magnetic structures, the interplay
of magnetic and structural transitions, small moment systems, and new
possibilities for exploring complex systems in the parameter space of
temperature, pressure, magnetic field and composition.
The Crystallography
college chairman (W. Kuhs) wrote Over one hour was devoted to the
discussion
the highest priority was given ex aequo to Thermal LADI and the D2B
upgrade. Both proposals were considered
of outstanding quality, both in its scientific case and its technical
feasibility. In a letter to D. Dubbers, he wrote I have seen the minutes of the last scientific council
that the
scientific case should be strengthened
I had the strong impression that a good
scientific case was made in the
powder workshop
. He referred to
the work of his group on recently discovered phases of ice and clathrates at
high pressure, and pointed out that increased intensity was needed for the
study of such meta-stable and transient phases.
The chairman of the
Science Council Powder Review (C. de
Novion) wrote in his interim report on instrument upgrades, after
organising a workshop attended by many participants from both pulsed and
synchrotron sources The super-D2B
upgrade project, presented within the new ILL Millennium Programme, was
considered as a first priority, in particular the new (and higher) detector
set. This would allow to use routinely
the D2B instrument in its highest resolution mode. In his final report in October, he wrote It is rated as first priority by the
Subcommittees 5a and 5b, which answer partially at least, to the requirement of
the S.C. (scientific case needs to be strengthened
). The first part of the project, new detectors
and collimators, is well defined and has a good scientific return on investment
ratio.
Indeed, the new chairman
of the Crystallography college (M.
Latroche) wrote in his October report
the subcommittee still strongly supports the D2B project. Structural determination by powder
diffraction is a basic work that cannot be bypassed
In a letter to D.
Dubbers, he wrote Our research group has
shown the complementarity between neutron and synchrotron techniques by solving
complex structures using joint refinement
from D2B and BM16 at ESRF. These structures cannot be solved from synchrotron
data alone, and neutron data were essential
The Magnetism college
chairman (R. Cywinski) further wrote
in October The subcommittee expressed
its strongest and unequivocal support for the super-D2B high resolution
diffractometer upgrade. Several
Experiments proposed during this round underlined the need for both high
resolution and high count rate. He
went on to give examples of D2B highlights including a new one dimensional
cuprate that can only be synthesised in very small quantities under very high
oxygen pressure. He concluded,
longer
term issues should not cloud the case for an urgent, well argued, and readily
achievable upgrade to the present D2B.