MCNSI meeting, February 2006 Contents: People –V. Ryukhtin left for part time only Multichannel focusing benders – continuation –resolution functions –how it works with thermal neutrons –application to strain-scanning Adding more flexibility –components displacement, velocity, rotation … –elimination of the surface effect in residual strain scanning by monochromator focusing Under development … RESTRAX – progress report

MCNSI meeting, February 2006 Lobster-eye device & focusing monochromator Lobster-eye device 20 (hor.) or 30 (ver.) blades thickness 0.5 mm m=3 supermirror (concave sides) elliptic & parabolic profiles optimisation: entry & exit width TAS - IN14 setup cold source straight 58 Ni guide, 6x12 cm 2 monochromator: PG 002, doubly focusing, =4.05 Å target (sample) area: 3x3 mm 2 optimisation: crystal curvatures splitting to vertical and horizontal sections

MCNSI meeting, February 2006 parabolic elliptic Ray-tracing in neutron benders reflection points for a batch of 500 histories

MCNSI meeting, February 2006 Incident beam in k-space transmitted reflected no dispersion of reflected neutrons => improved energy resolution Sample at the focal point: the guide selects quasi-parallel beam after the monochromator

MCNSI meeting, February 2006 Resolution function multichannel guide no guide

MCNSI meeting, February 2006 Wavelength dependence Neutron flux

MCNSI meeting, February 2006 Wavelength dependence Figure of merit: flux / energy resolution

MCNSI meeting, February 2006 Strain scanner - spatial resolution HK4: NPI strain diffractometer in-pile collimator 4x4 cm 2, =1.5Å bent Si monochromator without vertical focusing gauge volume defined by slits: 1 x 15 mm 2 vertically focusing guide 18 parabolic lamellae entry: 5 cm exit: 3.9 cm L=30 cm sample distance: 50 cm vertical resolution: 2 mm

MCNSI meeting, February 2006 Adding flexibility to SIMRES Console input/output for components parameters has been added (before, only some of them were accessible through configuration files) size position (displacement w.r.t. axis) orientation (Euler craddle) velocity shape + some component-specific parameters x, v x z, v z y, v y    v z = -5 m/s v z = +5 m/s example: Doppler shift for moving monochromator (phase- space transformers)

MCNSI meeting, February 2006 Surface effect Scanning residual strains near sample surface gauge volume is defined by scattering angle slit system sample surface

MCNSI meeting, February 2006 Surface effect Scanning residual strains near sample surface gauge volume center of mass is shifted near sample surface => shift in peak position dependence on monochromator curvature

MCNSI meeting, February 2006 Surface effect Transmission

MCNSI meeting, February 2006 Surface effect Reflection

MCNSI meeting, February 2006 Surface effect focusing condition for the monochromator, which reduces or eliminates surface effects experimentally tested (paper under preparation)

MCNSI meeting, February 2006 Concluding remarks Under development New release of SIMRES with above features documented NeXus configuration files (basic XML output already exists) Java GUI Java GUI - concept console I/O RESTRAX kernel Java application (Swing/SWT visual components) proc = Runtime.getRuntime().exec(“restax”); inpstr = proc.getInputStream(); inp = new BufferedReader(new InputStreamReader(inpstr));...