1. MCNSI meeting, 21-22 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

2. MCNSI meeting, 21-22 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

3. MCNSI meeting, 21-22 February 2006 parabolic elliptic Ray-tracing in neutron benders reflection points for a batch of 500 histories

4. MCNSI meeting, 21-22 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

5. MCNSI meeting, 21-22 February 2006 Resolution function multichannel guide no guide

6. MCNSI meeting, 21-22 February 2006 Wavelength dependence Neutron flux

7. MCNSI meeting, 21-22 February 2006 Wavelength dependence Figure of merit: flux / energy resolution

8. MCNSI meeting, 21-22 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

9. MCNSI meeting, 21-22 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)

10. MCNSI meeting, 21-22 February 2006 Surface effect Scanning residual strains near sample surface gauge volume is defined by scattering angle slit system sample surface

11. MCNSI meeting, 21-22 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

12. MCNSI meeting, 21-22 February 2006 Surface effect Transmission

13. MCNSI meeting, 21-22 February 2006 Surface effect Reflection

14. MCNSI meeting, 21-22 February 2006 Surface effect focusing condition for the monochromator, which reduces or eliminates surface effects experimentally tested (paper under preparation)

15. MCNSI meeting, 21-22 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));...