kunyang Dear All, Is there any way in TOPAS to do size-strain peak broadening for TOF neutron diffraction data? I know there are macros for broadening: LVol_FWHM_CS_G_L and e0_from_Strain . But both of them are related to the 2Th degrees, which are used in XRD and CW neutron diffraction. In TOF neutron diffraction, different peaks are not defined by 2Th degrees, but by tof or d-spacing. (I've tried to use the available macros LVol_FWHM_CS_G_L and e0_from_Strain in my TOF whole profile fitting, the fitting was improved and seems good. But it only gave a general values of domain size and microstrain for the whole profile, not for each peak. So I really doubt it. ) How can I do if I want to conduct the accurate peak broadening analysis for each peak in TOF? Thanks a lot for all your help. Best Regards, Kunyang
johnsoevans Try Alan's tutorial at: http://community.dur.ac.uk/john.evans/ta_tutorials/html/tof/tof.html
kunyang Dear John, Thanks for the soon reply. I've read this tutorial since a long time ago and that's what I've tried. But in Alan's tutorial, it only gave a general values of domain size and microstrain for the whole profile, not for each peak. The microstrain should be different corresponding to different peaks. It can't make sense if only obtain one microstrain value. Or maybe someone could explain that what's the exact meaning for the obtained value (only one) of microstrain by using "e0_from_Strain" into TOF analysis directly? Is it an average microstrain, or microstrain for the strongest peak?
johnsoevans The definitions of Alan's macros are as given in Balzar's paper which is linked from http://community.dur.ac.uk/john.evans/topas_workshop/size_strain.htm