Minutes of MCNSI meeting, 211004 at PSI KL/111204 Participants: - PSI: Heinz Heer, Uwe Filges, Geza Zsigmond - HMI: Klaus Lieutenant, Sergey Manoshin - ISIS: Dickon Champion - ILL: Emmanuel Farhi - INFM: Roberto Felici, Claudia Mondelli - NPI: Jan Saroun - Risoe: Kim Lefmann 1. Administrative matters: The meeting was held informal, e.g. no time limits to talks, in order to improve discussion. We agreed upon the project start for MCNSI to be 1/7-04 The milestones are fine till now, KLe will make an update to circulate to the partners. One milestone missing is contact to ANSTO and SNS partners. For ANSTO, the contact goes through Nick Hauser, for SNS Mark Hagen or Garreth Granroth. KLe will take contact. There has been many personnel changes: - PSI: GZ has arrived to the phase space transformation group. - HMI: GZ has left the VITESS group, Heloisa Bordallo has left for ILL, SM is leaving in March 2005. - ISIS: DC has moved to systems administration, but is still simulation coordinator. Roger Eccleston is leaving ISIS. - ILL: Virginie Hugovieux has finished her thesis, a 18 months post doc in simulation is announced. The ILL c-lab has been opened. - INFM: Lucia Alianelli has left for DIAMOND, restructurings are going on. - NPI: A Ukrainan post doc has been hired, Vasyl Ryukhtin. It is unclear if MCNSI can pay non-EU citizens. (I has later been cleared that there are no problems, KLe 111204) - Risoe: Restructurings are going on. 2. Presentations KLi presented the status of VITESS. There was a new major release 2.5 in april 04 and a minor release 2.5.1 in september 04. 370 different persons have downloaded VITESS over the years. The main new features in version 2.5 are neutron "colour", elliptic/parabolic guides, gradient flippers, Drabkin ressonators, tool to provide for a series of simulations, New tool are implemented to: output the position of components, improved graphical output, TOF "distance-time" plot, and angle calculation for triple-axis spectrometers. There is a thorough testing scheme for VITESS with a number of examples that cover (almost) all modules. Pending features for v. 2.6 are instrument visualization, Nexus format, and instrument optimization. The McStas-VITESS sharing of graphical tools was discussed. JS presented the status of RESTRAX. New features are flat-cone analyzer, and new samples (damped harmonic oscillator, quasielastic, SrRuO4, phonons). There is a web page with installation files and binaries. A virtual experiment on IN20 was presented. Here, the resulution function was computed and convoluted with phonon cross section. For IN14 a lobster eye (point-to-point) m=3 focusing device was simulated, and a factor of 10 could be gained at this instrument. Optimally, a factor 1500 intensity can be gained at a 1x1 mm^2 spot at 4.2 m from a 1x1 mm^2 source. A new RESTRAX version will appear in november 2005. EF presented the McStas developments. Version 1.8. was released in March 04. There has been 2000 single downloads of the package since then (but many of these downloads are performed by search robots, KL). The next release will appear around January 05. This will include MPI (parallel computing), new instrument editor, new source, monochromator, and sample components, simulation report in VRML, and a stand-alone system in Knoppix on a CD-ROM. After next release, McStas will work on a component manual, a web server for calculations, live monitors, and instrument optimizations. At the ILL, there is demand for polarized neutron simulations. Test of components and coordination of simulations are being performed. UF presented the work at PSI. Here, a converter between MATLAB and NeXus is being developed. Simulations have been performed at FOCUS with a proposed ballistic guide with both McStas and VITESS. Here, the flux at the sample position and the elastic resolution function has been compared with experiments. Some differences have been observed. It was suggested to let the FOCUS simulation become the next code-intercomparison project. SM presented the VITESS simulation of the HMI VSANS spectrometer. A system of multi-pinholes has been simulated. DC presented the work on ISIS. Much TS2 simulation is going on at the moment. Support for 64-bit processors is requested. Also polarization in McStas simulations is required. It has been discovered that scaling of absolute intensities is different between McStas and VITESS. INFM and Risoe work was covered by the presentation of EF. 3. Code Intercomparisons OSIRIS has been simulated in VITESS by Mark Telling, ISIS. Also some measurements have been performed. McStas simulations still need to be performed. It was agreed to measure I(lambda) and I(t) efter each chopper and at the sample position. Further, we measure vanadium signal at the detector at 3 scattering angles. Au foil data should be computed at the sample position. PG (002) analyzers are to be used. We should consider to include thermal diffuse scattering in the simulation. RF urged us to check our error bars using a linear regression method. KLe suggests repeated simulations for checks. 4. Virtual experiments EF presented results of virtual experiments on FOCUS, using liquid samples (inelastic). The agreement with real data was very good. Inspired from this, a discussion on the aims of virtual experiments was initiated. A seperate report on this will be circulated to email discussion. 5. Next meetings Next meeting is at HMI in April. We will consider if the autumn-05 meeting will be in conjunction with ICNS-05 in Sydney. This will be discussed over email before the end of this year. ------------------------------------------------------ Draft minutes of MCNSI TOF workshop at PSI, 221004 Participants: - PSI: Uwe Filges, Geza Zsigmond, Fanny Juryani, Stephan Jansen - HMI: Klaus Lieutenant, Sergey Manoshin - ISIS: Dickon Champion - ILL: Emmanuel Farhi - Risoe: Kim Lefmann 1. Developments at ILL EF presented the present works at ILL. There has been simulations of FOCUS and IN6. There has proven to be problems with the Fermi chopper components in McStas. This has led to a general consensus at the ILL that components should be properly tested against analytical models and that these tests should be documented. Further, the components should (when possible) be tested against experimental tests and benchmarked with respect to e.g. computational speed. The test results should be documented. The FOCUS simulations should be checked against the program of Hannu Mutka (ILL). 2. Developments at ISIS DC told that TS2 simulations were being carried out in McStas for the guide systems. OSIRIS has been tested with VITESS, but the HET simulations have failed due to the buggy Fermi chopper component in McStas. 3. Resolution tool for TOF in McStas KLe presented the new TOF resolution monitor in McStas. The neutron trajectories are being forced into one detector in one time bin to calculate the acceptance in (q,w) of that one channel. 4. Developments at HMI KLi presented simulations of the 75 long EXED TOF diffractometer. Only forward/backwards detectors are present as the spectrometer is meant for extreme environments. 5. Time focusing GZ presented simulations of a off-cut crystal analyzer for backscattering that performs time focusing, even for angles down to 80 degrees. This is to be used at the HERBIE spectrometer at TS2. 6. Discussion The discussions spawned a few interesting ideas for new components - Sapphire filter (or other transmission materials) - Phonon DOS into the vanadium sample - PSD detector with log time binning (in VITESS) - New bender that turns neutrons downwards (problems with gravity)