Dear All,
since I was present at the (by now infamous) ILL workshop, I will make a
brief comment. For those who still wonder what this is all about, Lachlan's
talk was part of a session entitled "Data acquisition and Software", in the
context of the workshop "Review of Neutron Diffraction ILL instruments for
Powder and Disordered Systems", held at the ILL on March 22-23 (this week).
Among many other quite interesting and useful things, Lachlan said that data
analysis from TOF powder instruments was hampered by the lack of adequate
data analysis software, and that some users may have to throw away otherwise
good data as a consequence of this. Therefore, pulsed neutron facilities
should devote more resources to developing software and worry less about
building new super-duper instruments.
I think that there is some inaccuracy in the phrasing of Lachlan's concept.
Pulsed neutron facilities have always devoted a significant amount of
resources to developing data analysis software, and this has benefitted the
Rietveld community at large. The most prominent example of this is GSAS,
which was written primarily for TOF diffraction at Los Alamos, and has
subsequently developed into a general-purpose Rietveld tool. GSAS was
recently listed as one of the most significant accomplishments of LANSCE.
Another example is RIETAN, developed primarily for the KEK diffractometers
but later evolved into a general-purpose code. Even when the aim is not
that of providing a general-purpose tool, pulsed facilities have always
developed software to help their users. Beside CCSL, which was obviously at
the centre of the controversy on Tuesday, let me mention the excellent
Rietveld package in use at IPNS, written by Frank Rotella and others.
True, it does not do x-rays and CW neutrons, but it is perfectly adequate
for data from the SEPD and GPPD diffractometers. As a consequence, I don't
think there is a single case when users had to throw away data because of
lack of software. If they did so, it was because the high information
content of TOF data was for them too hard of a nut to crack. Besides, in
terms of throwing away data, who is without sin....
Nevertheless, there is also some truth in what Lachlan said. TOF
diffraction is a much more "software-intensive" technique than CW neutron or
x-ray diffraction, and it will become increasingly so. If we take no
action, we may in fact soon reach the state that Lachlan so dreads. I have
full confidence that pulsed neutron facility will step up their efforts to
prevent this from happening.
Paolo
Dr. Paolo G. Radaelli
ISIS Facility
Rutherford Appleton Laboratory, Bldg. R3
Chilton, Didcot
Oxon. OX11 0QX
United Kingdom
Phone : (+44) 1235-44 5685
FAX : (+44) 1235-44 5642
e-mail: [EMAIL PROTECTED]
[EMAIL PROTECTED]
