Feb. 25Th - 2009 Erik Knudsen SMEXOS

Erik Knudsen, Peter Willendrup, Søren SchmidtRisø-DTU

Kim Lefmann, Andrea Prodi, Jana BaltserUniversity of Copenhagen

McXtrace - an X-ray Monte Carlo ray-tracing

software package

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Code structure

Kernel vs. Component developer

Kernel: Propagation between components Positioning Code generation

Component developer Physics Interactions X-ray<->Matter

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Code structure Component vs. Instrument

Instrument: Relative positions of components Interaction with simulator

Components: Interaction with X-ray wave packet

Kernel generated c: Not seen by users

Feb. 25Th - 2009 Erik Knudsen SMEXOS

How?

Initially Independent particles

State parameters

Time domain prop. => k domain prop.

NEUTRON

(r,v,p,s)

X-RAY

(r,k,p,,t)etc.

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Component code

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Instrument file

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Generated code “buzzwords”

“Embarrasingly parallel” - linear speedup <1000 nodes via MPI (as tested on Teragrid)

Clever sampling SPLIT Focus windows Rudimentary adaptive source

Mersenne Twister random generator

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Tie-ins with external software

General Philosophy: If someone else does it well, interface not reinvent

BUT

Have very simple versions in-house

Examples: Sources: Event files (from MCNPx, TRIPOLI4)

Samples: S(q,w) (ab.initio model from VASP)

Feb. 25Th - 2009 Erik Knudsen SMEXOS

SourcesNEUTRON X-RAY

Event File

McStas

Virtual Source

MCNPxTRIPOLI4

etc.

Event File/

Brilliance Spectra

McXtrace

Virtual Source

SPECTRAXOP

URGENTetc.

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Interface CGRAPHCGRAPH

Reflection list

Powder / Single Crystal component

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Examples and milestonesLow budget BL JJ-Xray SAX ESRF ID11

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Low-budget monochromtic BL

Image sizeh=(f1 / p )

f1

f2

p

Source size

Compact Be lens(f1)1/2=(f2)1/2=c

H

✔ ✔✔

Example : %108.0;8.0;10

11

E

EmmmmH

p

f

Feb. 25Th - 2009 Erik Knudsen SMEXOS

JJ-Xray SAXSo

urce

Slit

Slit Slit

Sam

ple

Det

ecto

r sys

tem

✘✔ ✔ ✔ ✔✘

Feb. 25Th - 2009 Erik Knudsen SMEXOS

ID11 Primary optics

✔ ✔ ✔ ✘ ✘✔ ✔

✘✘

Feb. 25Th - 2009 Erik Knudsen SMEXOS

ID11 Focussing Optics

TransfocatorTransfocatorWhite beam stopWhite beam stop

KB systemKB system

ML mirrorML mirror

LaueLaueCrystalsCrystalsTransfocatorTransfocator

White beam stopWhite beam stop

KB systemKB system

ML mirrorML mirror

TransfocatorTransfocatorWhite beam stopWhite beam stop

KB systemKB system

ML mirrorML mirror

LaueLaueCrystalsCrystals ✘✘

✘

✔

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Port neutron comps in McStasMonitors

almost all portable easy to port

=> port on use basisSources

most non-portableOptics

50/50 portable Either trivial or not at all

Samples 50/50 portable Fairly easy

Feb. 25Th - 2009 Erik Knudsen SMEXOS

X-ray comps. In McXtraceMonitors

Energy, wavelength, PSD...Sources

Simple flat, point, flat divergent, flat gaussian Optics

Simple perfect slit, Simple compound lenses, Cylindrical mirror

What do you need?

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Going forward

Post Doc working on partial coherence pre/post processing scheme

Existing matlab model

General invitation to everyone: Contribute as much as you wish!

Open Source (GPL) => Copyleft Website: www.mcxtrace.org Mailing list: mcxtrace-users@mcxtrace.org

Feb. 25Th - 2009 Erik Knudsen SMEXOS

Funding

NABIIT 4 years funding

2 postdoc., 2 Ph.D.-students

Simulation

Experimentation w. SAX on Nanodiscs

Validation of Simulations