From peter.willendrup at risoe.dk Fri Oct 1 14:18:17 2004 From: peter.willendrup at risoe.dk (Peter Willendrup) Date: Fri, 01 Oct 2004 14:18:17 +0200 (CEST) Subject: [neutron-mc] Test message, please ignore Message-ID: -- ------------------------------------- Peter Kjaer Willendrup, cand. scient Phone: (+45) 46 77 58 62 email: peter.willendrup at risoe.dk ------------------------------------- From peter.willendrup at risoe.dk Tue Oct 5 12:55:20 2004 From: peter.willendrup at risoe.dk (Peter Willendrup) Date: Tue, 05 Oct 2004 12:55:20 +0200 (CEST) Subject: [neutron-mc] Another test message, sorry... Message-ID: -- ------------------------------------- Peter Kjaer Willendrup, cand. scient Phone: (+45) 46 77 58 62 email: peter.willendrup at risoe.dk ------------------------------------- From farhi at ill.fr Tue Oct 5 12:11:15 2004 From: farhi at ill.fr (Emmanuel Farhi) Date: Tue, 05 Oct 2004 12:11:15 +0200 Subject: [neutron-mc] Not-vacuum neutron guide References: <20040618160825.GA17201@nf034.jinr.ru> Message-ID: <41627343.A33BFF61@ill.fr> Hello Timur, this is not implemented indeed. Anyway, if you wish to add an absorption law in guides, one solution is to use the EXTEND keyword, e.g.: COMPONENT MyGuide = Guide( ... , length=value) AT ... EXTEND %{ /* absorption law as a function of parameter 'length' */ p *= f(length, cross_section, ...) %} Emmanuel. Timur Elzhov wrote: > Hello, dear McStas experts. > > I was asked is it possible to compute not-vacuum (say, filled > with argon or air) neutron guide in McStas? > > Thanks. > > -- > WBR, > Timur. > _______________________________________________ > neutron-mc mailing list > neutron-mc at risoe.dk > http://neutron.risoe.dk/mailman/listinfo/neutron-mc -- What's up Doc ? -------------------------------------------- Emmanuel FARHI, http://www.ill.fr/Computing/people/Farhi \|/ ____ \|/ CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~ 6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\ Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From farhi at ill.fr Tue Oct 5 11:41:24 2004 From: farhi at ill.fr (Emmanuel Farhi) Date: Tue, 05 Oct 2004 11:41:24 +0200 Subject: [neutron-mc] DETECTOR_OUT_1D problem References: <20040916154128.GA5745@nf034.jinr.ru> Message-ID: <41626C44.D13116B1@ill.fr> Hello Timur, Indeed, the 1D data with 1 value are considered to be 0D monitors, which do not generate files. I can fix this for the next release. Please use 2 values for 1D monitors in the mean while. Emmanuel. Timur Elzhov wrote: > Dear McStas experts, > > When I try to save array of length 1(one) by DETECTOR_OUT_1D(..), > program writes file with comments only, and no data saved in (and > showed by mcplot). With length >= 2 all the OK. > Where am I wrong? > > Thanks. > > _______________________________________________ > neutron-mc mailing list > neutron-mc at risoe.dk > http://neutron.risoe.dk/mailman/listinfo/neutron-mc -- What's up Doc ? -------------------------------------------- Emmanuel FARHI, http://www.ill.fr/Computing/people/Farhi \|/ ____ \|/ CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~ 6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\ Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From farhi at ill.fr Tue Oct 5 13:39:03 2004 From: farhi at ill.fr (Emmanuel Farhi) Date: Tue, 05 Oct 2004 13:39:03 +0200 Subject: [neutron-mc] Propagation in neutron guide References: <20040625160758.GA1421@nf034.jinr.ru> Message-ID: <416287D7.7BDBE6F9@ill.fr> Hi again Timur, If we consider that the source is far away from the guide entry, and its dimensions are realistic, then the neutron wave can be considered as a spherical wave. In fact, if the source emission is quasi-isotropic, then the portion of the flux that reaches the guide entry is the solid angle/4Pi times the total neutron flux coming out of the source. This is where the r^2 factor comes into account, and it stands for the fact that the total flux on the neutron wave spherical surface is constant as the radius increases. In guides, the neutron wave is planar, and the total flux is directly transmited. Thus there is no distance dependency, except for absorption. Emmanuel. Timur Elzhov wrote: > Dear McStas experts, > > I noticed, that in "source" components the neutron weight is > multiplicated by 1/r^2 factor. That's clear -- that's reverse > square law for isotropic radiation. But I do not see this multiplier > on neutron propagation in the guides. I looked through macro PROP_Z0 > as well as PROP_DT(), but found nothing about 1/r^2. > > Why? > > Regards, > Timur V. Elzhov > > _______________________________________________ > neutron-mc mailing list > neutron-mc at risoe.dk > http://neutron.risoe.dk/mailman/listinfo/neutron-mc -- What's up Doc ? -------------------------------------------- Emmanuel FARHI, http://www.ill.fr/Computing/people/Farhi \|/ ____ \|/ CS-Group ILL4/156, Institut Laue-Langevin (ILL) Grenoble ~@-/ oO \-@~ 6 rue J. Horowitz, BP 156, 38042 Grenoble Cedex 9,France /_( \__/ )_\ Work :Tel (33/0) 4 76 20 71 35. Fax (33/0) 4 76 20 76 48 \__U_/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From Timur.Elzhov at jinr.ru Mon Nov 1 09:36:10 2004 From: Timur.Elzhov at jinr.ru (Timur Elzhov) Date: Mon, 01 Nov 2004 11:36:10 +0300 Subject: [neutron-mc] handling of `POLARISATION PARAMETERS' Message-ID: <20041101083610.GA1003@nf034.jinr.ru> Dear McStas experts, Sorry, but I couldn't understand how the subj should be used. I'd like to generate, say, the polarized neutron with certain polarization in the `source' component, and then use these components (sx,sy,sz) in the following components. But I read in the manual, POLARISATION PARAMETERS (sx,sy,sz) This line is necessary only if the comp onent handles p mo difies the spin vector. For an instrument to handle required that *one* of the components contains this line. and, "s1 & s2 in the STATE PARAMETERS obsolete and cannot be used". I included POLARISATION PARAMETERS(sx,sy,sz) in my `source' and simply `printf' them. I've got (0,1,0), i.e. polarized beam along `y' axis. Well, and what? :) How can I generate polarized beam along `z' axis (probably, by setting sy = 0 and sz = 1 in the `source'?), and then analize them with (any) monitor? Thanks. -- WBR, Timur From farhi at ill.fr Mon Nov 1 13:01:35 2004 From: farhi at ill.fr (Emmanuel FARHI) Date: Mon, 01 Nov 2004 13:01:35 +0100 (CET) Subject: [neutron-mc] handling of `POLARISATION PARAMETERS' In-Reply-To: <20041101083610.GA1003@nf034.jinr.ru> References: <20041101083610.GA1003@nf034.jinr.ru> Message-ID: <57286.193.49.43.124.1099310495.squirrel@mail.ill.fr> Hello Timur, this is true, if you wish to set the polarisation, just set the sx, sy and sz values. In order to monitor the polarisation, you may use the Monitor_nD(options="sx sy sz") An example is given in the He3 cell component (contrib), as well as an instrument example in the www.ill.fr/ill_lib.html#instruments page. Emmanuel. > Dear McStas experts, > > Sorry, but I couldn't understand how the subj should be used. > I'd like to generate, say, the polarized neutron with certain > polarization in the `source' component, and then use these > components (sx,sy,sz) in the following components. But I read > in the manual, > > POLARISATION PARAMETERS (sx,sy,sz) > This line is necessary only if the comp onent handles p > mo difies the spin vector. For an instrument to handle > required that *one* of the components contains this line. > > and, "s1 & s2 in the STATE PARAMETERS obsolete and cannot be used". > > I included POLARISATION PARAMETERS(sx,sy,sz) in my `source' and > simply `printf' them. I've got (0,1,0), i.e. polarized beam along > `y' axis. Well, and what? :) How can I generate polarized beam > along `z' axis (probably, by setting sy = 0 and sz = 1 in the > `source'?), and then analize them with (any) monitor? > > Thanks. > > > -- > WBR, > Timur > > _______________________________________________ > neutron-mc mailing list > neutron-mc at risoe.dk > http://neutron.risoe.dk/mailman/listinfo/neutron-mc -- FARHI Emmanuel Groupe DS/CS, ILL4/156, Tel 04 76 20 71 35 ILL, Grenoble From farhi at ill.fr Fri Nov 5 23:01:26 2004 From: farhi at ill.fr (Emmanuel FARHI) Date: Fri, 05 Nov 2004 23:01:26 +0100 (CET) Subject: [neutron-mc] ILL 18 months position: McStas simulations and development Message-ID: <34183.193.49.43.124.1099692086.squirrel@mail.ill.fr> Dear Neutron MC users, A short-term position is currently available in the Computing for Science group at the Institut Laue Langevin, Grenoble, France (http://www.ill.fr). The work involved concerns the use and development of neutron ray-tracing, Monte Carlo codes to simulate neutron guides and instruments at ILL. This work is part of an on-going effort to improve neutron instrumentation and offer the best possible instruments at ILL. The successful candidate will use the McStas code to simulate neutron guides and instruments, in collaboration with ILL scientists. Simulations will be carefully validated and benchmarked against measurements. Development of the McStas code will involve new components for polarised neutrons and for samples and the sample environment. He/she should have a PhD in one of the physical sciences and be familiar with neutron scattering at large scale facilities. Good computing skills (C language, Unix/Linux systems) are essential. The duration of this position is 18 months. The salary will be about 3000 Euros/month brut, depending on age and experience. Applications, including a CV, a letter of motivation and two letters of recommendation, should be sent to Emmanuel Farhi or Mark Johnson by 15.12.2004. -- FARHI Emmanuel Groupe DS/CS, ILL4/156, Tel 04 76 20 71 35 ILL, BP 156, Grenoble Cedex 9, France