Meeting: 16/11/99 M. Johnson, I. Anderson, E. Farhi, R. Ghosh
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The aim of the meeting was to establish some degree of organisation to share software developments on this topic both internally at ILL and with external active groups. To gain support and to obtain enduring value it would be necessary to coordinate activities, ideally within one framework of general concepts.

One prime tool under heavy development at present was mcstas from Risoe (Nielsen et al). This deals primarily with guides, monochromators and crystal components. Other groups at HMI, and ISIS have worked on Monte-Carlo (M/C) simulations of TOF instrumentation.

Manpower available

Several scientists (EF, Thomas Hansen, Trefor Roberts) have been developing mcstas code and configurations. Full-time workers available now and in the near future include:

Lucia Alianelli (DPT-IA) who is at present working on XOP with Manuel Sanchez del Rio. This is a GUI to SHADOW, an X-ray ray-tracing package, which is being adapted to include neutrons.
A potential post-doc (2-years) based at ILL, though attached to INFM, under the European SCANS programme for simulations extending the use of mcstas code.
Manpower endorsed and accepted to be part of the ILL Millenium Programme.

Development Activities at ILL
Inevitably at ILL there will always be a small core of enthusiastic developers, and a larger group of knowledgeable users. To maximise interest from both internal communities a half-day meeting including one or two external invitees will present the present status of current packages for comparison.

Although mcstas can serve as a basis for the incident beamline for most instruments at ILL, detailed M/C calculations for inelastic TOF chopper instruments have been comprehensively studied elsewhere, notably ISIS and HMI, and a future hope might be to align these calculations with mcstas

A tentative date was proposed for the meeting: 21st January, during the reactor shutdown.

Invitees to be contacted:
Nielsen (EF)
Hagen   (RG)
Sanchez del Rio (IA)
HMI representative (IA)

Programme to include:
EF + Jiri Kulda         mcstas and RESTRAX for modelling 3-axis experiments
Manolo Sanchez del Rio  SHADOW now and tomorrow..
Mark Hagen              TOF simulations +- mcstas
HMI rep                 HMI simulation programs
Kristen Nielsen         Progress with mcstas
Thomas Hansen           modelling  diffractometers

Budget for invitees would be from College I.

Support from CS

Before the meeting it would be useful to prepare (? start preparing) skeleton examples using mcstas of typical instruments in each group. EF was willing to help RG in this activity. Such examples could serve as templates for further discussions or even as the start of a depository of models.

EF has already had encouraging responses from Risoe concerning sharing storage and documentation of new component modules.

In-house an informal "mcstas-M/C FAQ and NEWS" web-page with links to Risoe might help collaborations, and maintaining a documented depository might alleviate the problem of significant effort being wasted as students and contributors quit ILL.

In the longer term one could progressively introduce GUI controlled simulations onto ILL intruments to help users set up experiments, and allow responsibles to quantify proposed instrument improvements.