You are right Radovan. The sample mail-in system is one way of improving SR and N access times. "Discretionary time" reserved for people who have a hot experiment and can come at short notice, is another, together with speeding up the usual proposal system. These mechanisms already apply at ILL, but on-site manpower is a limiting factor. And yes, a SR pattern will almost always be superior to a lab pattern, because you can afford an instrument to produce a cleaner pattern, and it is also easier with a monochromated white beam. ________________________________ Dr Alan Hewat, NeutronOptics Grenoble, FRANCE (from phone) [email protected] +33.476984168 VAT:FR79499450856 http://NeutronOptics.com/hewat _______________________________
On Wed, 6 Sept 2023, 11:31 Radovan Cerny, <[email protected]> wrote: > No, you are not provocative Alan. You are right. I have reacted only to > the X-ray discussion (no neutrons in the labs). > It is a pity that the procedure for getting the beamtime at the > synchrotron and neutron sources is still so time-consuming. At least at the > synchrotron, there is an activity to introduce or improve already existing > mail-in system. I have a feeling that there is enough synchrotron beamtime > for everybody to collect standard powder patterns. 20-60 sec / pattern with > 2D detector + few min. for sample mounting is not so much. > Who has analyzed powder patterns from synchrotron will never come back to > the lab (this is provocative 🙂) > > Radovan > > > Radovan Cerny > DQMP > Université de Genève > 24, quai Ernest-Ansermet > CH-1211 Geneva 4, Switzerland > mailto : [email protected] > URL : http://www.unige.ch/sciences/crystal/cerny/rcerny.htm > ------------------------------ > *De :* [email protected] <[email protected]> de la part > de Alan W Hewat <[email protected]> > *Envoyé :* mercredi 6 septembre 2023 11:17 > *À :* Le Bail Armel <[email protected]> > *Cc :* Rietveld_L <[email protected]> > *Objet :* [EXTERNAL] Re: Step-like basline > > "*The biggest improvement was synchrotron radiation*". > No. The biggest improvement for the profile refinement of atomic and > magnetic structures (Rietveld refinement in the strict sense) was high > resolution neutron powder diffractometers with large area detectors :-) > Even SR gives undue weight to heavy atoms, can suffer from systematic > errors due to small samples, and of course is "not ideal" for magnetism, > important for the properties of many materials. SR has some advantages to > counter these disadvantages, but not for most new materials. Lab x-rays can > do some structural work, but have most application for materials > characterisation by multi-component profile refinement, when you need a > result now, and not in 6 months time. > > But Radovan, is just being provocative (like me). > > Alan > > > ________________________________ > Dr Alan Hewat, NeutronOptics > Grenoble, FRANCE (from phone) > [email protected] > +33.476984168 VAT:FR79499450856 > http://NeutronOptics.com/hewat > _______________________________ > > > On Wed, 6 Sept 2023, 10:48 Le Bail Armel, <[email protected]> wrote: > > Hi, > > In the same subject. > > A special "powder pattern" to play with (try to explain all peaks) : > > http://cristal.org/muscovite.pdf > > Best > > Armel > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <[email protected] > > > Send commands to <[email protected]> eg: HELP as the subject with no body > text > The Rietveld_L list archive is on > http://www.mail-archive.com/[email protected]/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <[email protected]> Send commands to <[email protected]> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/[email protected]/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
