Using Diffractometersin SPEC

Geometries

fourc, kappa fivec, sixc, psic twoc, w21v, w21h s1d2, s2d2 zaxis ….

Reminder

Diffractometer : working in crystal coordinates: HKL

H,K,L to motor positions: matrix UB A particular geometry gives different modes

of operation.

Motor names are fixed by the geometry• ( and always first in wa… magic! )

A diffraction experiment

Enter lattice parameters: setlat Defining orientation matrix:

– setor0, setor1, or0, or1

Deciding working mode– setmode, freeze– setsector

… and work: – wh, ca, ci,pa, hklscan,kscan...

Operation Modes

Use modes to fix some conditions

freeze

Orientation Matrix

or0, or1 ( setor0, setor1 ) can be entered manually: enterUB or by refinement: ( several reflexions )

• reflex_beg

• reflex

• reflex_end

You can print it

Usage

pa ( show current settings ) wh ( show h,k,l and motor positions ) ca, ci ( calculates and show, no move ) br ( go to brag… 1,0,1)

Scans ( of course )

hklscan and variants • hscan

• kscan

• lscan

Radial scans: ( follow a line )

• hkradial, hlradial, klradial

Circular scans: ( doing an arc )

• hkcircle, hlcircle, hkcircle

More

Save• will put all parameters into a file

• load it with ‘do filename’

Internals

calcA• calculates A[] from HKL

calcHKL• calculates HKL from A[]

• leaves values in H,K and L

Who said pseudo-motors?