From sdannyp at campus.technion.ac.il Tue Aug 22 21:56:47 2017 From: sdannyp at campus.technion.ac.il (sdannyp at campus.technion.ac.il) Date: Tue, 22 Aug 2017 19:56:47 +0000 Subject: [mcstas-users] A few questions regarding mcstas Message-ID: Hello, I am new to Mcstas, and I am trying to simulate a double axis diffractometer. I am running into a few difficulties with the simulation: 1) I want to define a group of collimators and monitor detectors that are positioned radially around the sample, each having it's own scanning angle. This results in only the first collimator interacting with the neutron ray, as any neutron that misses gets ABSORB'ed. How do I circumvent this? 2) I would like to compare the results of the simulation with the theoretical Caglioti resolution function, that depends on the divergence angles of the collimators and the mosaic spread. As I've noticed, Mcstas uses a triangular transmission function for the collimators and not a gaussian one. Will the result be different than the Caglioti curve, and is this approximation reasonable for real collimators? 3) Are there any plans for a Mcstas workshop in the near future, and if so, where can I get more information? Thanks in advance, Daniel -------------- next part -------------- An HTML attachment was scrubbed... URL: From pkwi at fysik.dtu.dk Wed Aug 23 11:14:13 2017 From: pkwi at fysik.dtu.dk (=?utf-8?B?UGV0ZXIgS2rDpnIgV2lsbGVuZHJ1cA==?=) Date: Wed, 23 Aug 2017 09:14:13 +0000 Subject: [mcstas-users] A few questions regarding mcstas In-Reply-To: References: Message-ID: <08A57324-5F34-4850-9982-96CA2A3AE5A2@fysik.dtu.dk> Dear Daniel, On 22 Aug 2017, at 21:56 , sdannyp at campus.technion.ac.il wrote: I am new to Mcstas, and I am trying to simulate a double axis diffractometer. I am running into a few difficulties with the simulation: 1) I want to define a group of collimators and monitor detectors that are positioned radially around the sample, each having it's own scanning angle. This results in only the first collimator interacting with the neutron ray, as any neutron that misses gets ABSORB'ed. How do I circumvent this? From what I understand you are trying to achieve, you should probably add two GROUP?s of components (see the manual around section 4.4 and forward), something like: COMPONENT Colli1 = Collimator(?) AT (?) GROUP Collimators COMPONENT Colli2 = Collimator(?) AT (?) GROUP Collimators . . . COMPONENT Moni1 = PSD_monitor(?) AT (?) GROUP Collimators COMPONENT Moni2 = PSD_monitor(?) AT (?) GROUP Collimators COMPONENT Moni3 = PSD_monitor(?) AT (?) GROUP Collimators . . . COMPONENT MoniN = PSD_monitor(?) AT (?) GROUP Collimators - Also have a look in the examples folder of your McStas installation, there is a number of instruments using the GROUP keyword for components working ?in parallel?. My reason to think that this will help is that GROUP more or less means if ( ABSORBed || ! SCATTERED ) try_the_next_comp; An important detail is that the members of the GROUP are placed next to each other in the instr file, and one makes sure that all neutrons are eventually SCATTERED (meaning that it can in some cases be good to add an Arm() EXTEND?ed by a SCATTER; at the end of the group. 2) I would like to compare the results of the simulation with the theoretical Caglioti resolution function, that depends on the divergence angles of the collimators and the mosaic spread. As I've noticed, Mcstas uses a triangular transmission function for the collimators and not a gaussian one. Will the result be different than the Caglioti curve, and is this approximation reasonable for real collimators? In my understanding, a triangular transmission function is closer to measurement reality than the Caglioti gaussian. :-) 3) Are there any plans for a Mcstas workshop in the near future, and if so, where can I get more information? Nothing planned as of yet, but I am sure there will be one during first half of 2018. Will keep you in the loop. Best and good luck simulating, Peter Peter Kj?r Willendrup Senior Research Engineer, Special Advisor DTU Physics [cid:image001.gif at 01CCCAF1.5E6331F0] Technical University of Denmark [cid:image002.gif at 01CCCAF1.5E6331F0] Department of Physics Fysikvej Building 307 DK-2800 Kongens Lyngby Direct +45 2125 4612 Mobil +45 2125 4612 Fax +45 4593 2399 pkwi at fysik.dtu.dk -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.gif Type: image/gif Size: 58 bytes Desc: image001.gif URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.gif Type: image/gif Size: 1055 bytes Desc: image002.gif URL: From DFerraro at invap.com.ar Wed Aug 23 17:32:10 2017 From: DFerraro at invap.com.ar (Diego Ferraro) Date: Wed, 23 Aug 2017 12:32:10 -0300 Subject: [mcstas-users] MCStas usage: simple TOF question In-Reply-To: <08A57324-5F34-4850-9982-96CA2A3AE5A2@fysik.dtu.dk> References: <08A57324-5F34-4850-9982-96CA2A3AE5A2@fysik.dtu.dk> Message-ID: <599D75CA020000F900025947@gw1.invap.com.ar> Dear All, I'm new in McStas modelling and I'm having some problems understanding the results from Code. I'm using the 2.4.1 version to model a simple TOF example using a reactor beam as source (thermal) and a disk chopper. My model (se attached .png) consist of Maxwelian source (using Source_gen), a non-reflecting beam (using guide with m=0), a Chopper (using DiskChopper) another ~5m beam after the chopper and finally, a collimator and an MCA in time mode (modeled using a TOF_monitor with 1000 Time channels). I get the results in TOF monitor and several questions arise: 1 - The results are per unit time (1/s) as for the flux ? (i.e. the TOF monitor represents the acumulated counts in 1s with efficiency =1) ? 2 - I should expect that the transmision of the Chopper would change with its velocity, but I found no dependency in TOF monitor (see attached Figure). Obviously I am missing something, but I cannot figure which is the problem. Thanks in advance for any help, Diego Ferraro -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: geometry.png Type: image/png Size: 22163 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: ResultsTOF.png Type: image/png Size: 34603 bytes Desc: not available URL: From lefmann at nbi.ku.dk Wed Aug 23 17:15:32 2017 From: lefmann at nbi.ku.dk (Kim Lefmann) Date: Wed, 23 Aug 2017 17:15:32 +0200 Subject: [mcstas-users] MCStas usage: simple TOF question In-Reply-To: <599D75CA020000F900025947@gw1.invap.com.ar> References: <08A57324-5F34-4850-9982-96CA2A3AE5A2@fysik.dtu.dk> <599D75CA020000F900025947@gw1.invap.com.ar> Message-ID: <599D9C14.2080703@nbi.ku.dk> Dear Diego, The chopper on a reactor source works a little counter-intuitive. Could you send me the McStas instrument file, so I can diagnose better? best, Kim On 08/23/2017 05:32 PM, Diego Ferraro wrote: > Dear All, > I'm new in McStas modelling and I'm having some problems > understanding the results from Code. I'm using the 2.4.1 version to > model a simple TOF example using a reactor beam as source (thermal) > and a disk chopper. My model (se attached .png) consist of Maxwelian > source (using Source_gen), a non-reflecting beam (using guide with > m=0), a Chopper (using DiskChopper) another ~5m beam after the chopper > and finally, a collimator and an MCA in time mode (modeled using a > TOF_monitor with 1000 Time channels). > I get the results in TOF monitor and several questions arise: > 1 - The results are per unit time (1/s) as for the flux ? (i.e. > the TOF monitor represents the acumulated counts in 1s with efficiency > =1) ? > 2 - I should expect that the transmision of the Chopper would > change with its velocity, but I found no dependency in TOF > monitor (see attached Figure). > Obviously I am missing something, but I cannot figure which is the > problem. > Thanks in advance for any help, > Diego Ferraro > > > > > > _______________________________________________ > mcstas-users mailing list > mcstas-users at mcstas.org > http://mailman.mcstas.org/cgi-bin/mailman/listinfo/mcstas-users -------------- next part -------------- An HTML attachment was scrubbed... URL: From DFerraro at invap.com.ar Wed Aug 23 21:29:05 2017 From: DFerraro at invap.com.ar (Diego Ferraro) Date: Wed, 23 Aug 2017 16:29:05 -0300 Subject: [mcstas-users] MCStas usage: simple TOF question In-Reply-To: <599D75CA020000F900025947@gw1.invap.com.ar> References: <08A57324-5F34-4850-9982-96CA2A3AE5A2@fysik.dtu.dk> <599D75CA020000F900025947@gw1.invap.com.ar> Message-ID: <599DAD51020000F90002599D@gw1.invap.com.ar> Sorry I made a mistake in the frequency (I was considering period instead of frequency). I include the updated figure in the attachment (in log scale). Nevertheless I cannot figure out the results behaviour of the TOF monitor for this configuration. Thanks again, Diego >>> "Diego Ferraro" 23/08/2017 12:32 p.m. >>> Dear All, I'm new in McStas modelling and I'm having some problems understanding the results from Code. I'm using the 2.4.1 version to model a simple TOF example using a reactor beam as source (thermal) and a disk chopper. My model (se attached .png) consist of Maxwelian source (using Source_gen), a non-reflecting beam (using guide with m=0), a Chopper (using DiskChopper) another ~5m beam after the chopper and finally, a collimator and an MCA in time mode (modeled using a TOF_monitor with 1000 Time channels). I get the results in TOF monitor and several questions arise: 1 - The results are per unit time (1/s) as for the flux ? (i.e. the TOF monitor represents the acumulated counts in 1s with efficiency =1) ? 2 - I should expect that the transmision of the Chopper would change with its velocity, but I found no dependency in TOF monitor (see attached Figure). Obviously I am missing something, but I cannot figure which is the problem. Thanks in advance for any help, Diego Ferraro -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: ResultsTOF_log.png Type: image/png Size: 32278 bytes Desc: not available URL: From farhi at ill.fr Fri Aug 25 12:24:37 2017 From: farhi at ill.fr (Emmanuel FARHI) Date: Fri, 25 Aug 2017 12:24:37 +0200 Subject: [mcstas-users] iFit 1.10 released (Aug 2017) Message-ID: <593b5ef9-e77f-06d7-7bac-7f9f18315a56@ill.fr> An HTML attachment was scrubbed... URL: From j.voigt at fz-juelich.de Tue Sep 5 14:06:32 2017 From: j.voigt at fz-juelich.de (=?utf-8?B?IlZvaWd0LCBKw7ZyZyI=?=) Date: Tue, 5 Sep 2017 12:06:32 +0000 Subject: [mcstas-users] Action of a WHEN condition Message-ID: <0CD566B0-C209-4F5C-8E52-64EEE132A347@fz-juelich.de> Dear McStas users, I want to model a bispectral switch, where a bender is used to reflect the cold neutrons into the neutron guide, while this bender can be removed to open the way for the thermal neutrons from the ESS butterfly moderator. As the bender deflects the beam, I need to rotate the respective component by the deflection angle, so I have a ROTATED statement. What happens to the coordinate system of the subsequent components, if I use a WHEN statement to ignore the bender in case I want to use neutrons only from the thermal moderator? Will it be rotated? Best regards J?rg =================================================================================== Dr. J?rg Voigt J?lich Centre for Neutron Science JCNS und Peter Gr?nberg Institut PGI JCNS-2, PGI-4: Streumethoden Forschungszentrum J?lich GmbH _/ _/_/ 52425 J?LICH _/ _/_/_/ _/_/_/ _/_/_/ _/ _/ DEUTSCHLAND _/ _/ _/ _/ _/_/ _/ Tel. +49 2461 61 6020 _/ _/ _/ _/ _/ _/_/ _/ Fax +49 2461 61 2610 _/_/ _/_/_/ _/ _/ _/_/_/ _/_/_/_/ j.voigt at fz-juelich.de =================================================================================== -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 4969 bytes Desc: not available URL: From andrew.jackson at esss.se Tue Sep 5 14:20:24 2017 From: andrew.jackson at esss.se (Andrew Jackson) Date: Tue, 5 Sep 2017 12:20:24 +0000 Subject: [mcstas-users] Action of a WHEN condition In-Reply-To: <0CD566B0-C209-4F5C-8E52-64EEE132A347@fz-juelich.de> References: <0CD566B0-C209-4F5C-8E52-64EEE132A347@fz-juelich.de> Message-ID: Dear J?rg I would place the components downstream of the bispectral switch in relation to the moderator or an Arm starting there (which might have the correct rotation of the whole beamline wrt the moderator) rather than the previous component - in reality they will be fixed, so you are then just inserting or not the switch (which has a rotation of its own). I do something similar to enable different collimation lengths in a SANS instrument - I place each guide piece with respect to an Arm that is at the beginning of the collimation rather than with respect to previous components, a combination of WHEN statements allows me to select which pieces are in the beam. This does mean you need to pay a bit more attention to lengths of components etc, but probably better matches reality. Andrew ________________________________________________________________________ Andrew Jackson Instrument Scientist - Small Angle Scattering Deputy Head of Neutron Instruments Division European Spallation Source, P.O Box 176, SE-221 00 Lund, Sweden Adjunct Associate Professor (Ajungerad Lektor) Physical Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden Mobile: +46 72 179 2015 E-mail: andrew.jackson at esss.se www.esss.se ________________________________________ From: mcstas-users [mcstas-users-bounces at mcstas.org] on behalf of "Voigt, J?rg" [j.voigt at fz-juelich.de] Sent: Tuesday, September 05, 2017 2:06 PM To: mcstas-users at mcstas.org Subject: [mcstas-users] Action of a WHEN condition Dear McStas users, I want to model a bispectral switch, where a bender is used to reflect the cold neutrons into the neutron guide, while this bender can be removed to open the way for the thermal neutrons from the ESS butterfly moderator. As the bender deflects the beam, I need to rotate the respective component by the deflection angle, so I have a ROTATED statement. What happens to the coordinate system of the subsequent components, if I use a WHEN statement to ignore the bender in case I want to use neutrons only from the thermal moderator? Will it be rotated? Best regards J?rg =================================================================================== Dr. J?rg Voigt J?lich Centre for Neutron Science JCNS und Peter Gr?nberg Institut PGI JCNS-2, PGI-4: Streumethoden Forschungszentrum J?lich GmbH _/ _/_/ 52425 J?LICH _/ _/_/_/ _/_/_/ _/_/_/ _/ _/ DEUTSCHLAND _/ _/ _/ _/ _/_/ _/ Tel. +49 2461 61 6020 _/ _/ _/ _/ _/ _/_/ _/ Fax +49 2461 61 2610 _/_/ _/_/_/ _/ _/ _/_/_/ _/_/_/_/ j.voigt at fz-juelich.de =================================================================================== From DFerraro at invap.com.ar Tue Sep 5 21:24:43 2017 From: DFerraro at invap.com.ar (Diego Ferraro) Date: Tue, 05 Sep 2017 16:24:43 -0300 Subject: [mcstas-users] compiling Virtual_mcnp_ss_input component question In-Reply-To: References: <0CD566B0-C209-4F5C-8E52-64EEE132A347@fz-juelich.de> Message-ID: <59AECFCB020000F900025E4C@gw1.invap.com.ar> Dear forum, I'm trying to use an MCNP SSW source in my McStas input through the Virtual_mcnp_ss_input component. I'm using MCstas 2.4.1 in Windows (I have previously installed strawberry perl package), but when compiling instrument I get an error "C:/mcstas-2.4.1/miniconda3/Library/mingw-w64/bin/../lib/gcc/i686-w64-mingw32/5.3.0/../../../../i686-w64-mingw32/bin/ld.exe: cannot find -lgfortran collect2.exe: error: ld returned 1 exit status" I understand that the fortran compiler (required in Virtual_mcnp_ss_input) is not found, but I assumed that strawberry should include this. Does anyone experienced the same problem? Thanks, Diego -------------- next part -------------- An HTML attachment was scrubbed... URL: From pkwi at fysik.dtu.dk Tue Sep 5 21:23:06 2017 From: pkwi at fysik.dtu.dk (=?iso-8859-1?Q?Peter_Kj=E6r_Willendrup?=) Date: Tue, 5 Sep 2017 19:23:06 +0000 Subject: [mcstas-users] compiling Virtual_mcnp_ss_input component question In-Reply-To: <59AECFCB020000F900025E4C@gw1.invap.com.ar> References: <0CD566B0-C209-4F5C-8E52-64EEE132A347@fz-juelich.de> <59AECFCB020000F900025E4C@gw1.invap.com.ar> Message-ID: Dear Diego, Since defaulting now to the Python-based tools, we have switched to the c-compiler provided by the miniconda3 Python. Maybe try checking if there is a libgfortran that you can install into the miniconda - by conda search gfortran through the mcstas-2.4.1-shell? Alternatively you could consider using the MCPL input comp - a tool exists do convert SSW to MCPL format - see https://mctools.github.io/mcpl/ Best and hope this helps, Peter On 5 Sep 2017, at 21:24 , Diego Ferraro > wrote: Dear forum, I'm trying to use an MCNP SSW source in my McStas input through the Virtual_mcnp_ss_input component. I'm using MCstas 2.4.1 in Windows (I have previously installed strawberry perl package), but when compiling instrument I get an error "C:/mcstas-2.4.1/miniconda3/Library/mingw-w64/bin/../lib/gcc/i686-w64-mingw32/5.3.0/../../../../i686-w64-mingw32/bin/ld.exe: cannot find -lgfortran collect2.exe: error: ld returned 1 exit status" I understand that the fortran compiler (required in Virtual_mcnp_ss_input) is not found, but I assumed that strawberry should include this. Does anyone experienced the same problem? Thanks, Diego _______________________________________________ mcstas-users mailing list mcstas-users at mcstas.org http://mailman.mcstas.org/cgi-bin/mailman/listinfo/mcstas-users -------------- next part -------------- An HTML attachment was scrubbed... URL: