Set the Attributes of UB Matrices

UB matrices are used only the the on-line code. But since their attributes are changed like any other GQE, they also appear here.

/asn=int_expr $\in$ [1,4]

/angle_set_no=int_expr $\in$ [1,4]

Used for the determination of the diffractometer angles in the constant plane mode. A certain q-vector can be moved into the scattering position by four different sets of angles. ASN chooses one of them.

/centering_mode=int_expr

A flag that is used by scan/reflection. It determines how the best position is found during the centering of a reflection.

0 - Center of gravity. 1 - Highest y-value.

/chi_zero=float_expr

/omega_zero=float_expr

/two_theta_zero=float_expr

Sets the offsets of the diffractometer angles.

/com$*$ment=text_expr

Sets the command line.

/cv_ration=float_expr

Used by scan/reflection. The centering is terminated for an angle, if this convergence test is passed: abs(new_angle - old_angle)/ (2$*$FWHM) < cv_ration.

/gk$i$=float_expr $i$ $\in$ [1,3]

The lattice constants.

/gw$i$=float_expr $i$ $\in$ [1,3]

The lattice angles.

/h1$i$=float_expr $i$ $\in$ [1,3]

/h2$i$=float_expr $i$ $\in$ [1,3]

These two vectors define the constant plane.

/moving_fine=int_expr

A flag that determines whether the ”fine" motors are used for the $\omega$ rotation.

/np_scan=int_expr

Used by scan/reflection. The number of points that are used for the angular scans during the centering of a reflection.

/n_iter=int_expr

Used by scan/reflection. This menu centers a reflection by moving the diffractometer angles in the order of centering_order, e.g. ”otc" for $\omega$, two_theta and $\chi$. Every angle performs a coarse scan first in order to find a reasonable scanning range. N_iter is the number of fine scans that follow. If the convergence test is passed before n_iter iterations, the centering procedure is terminated.

/psi=float_expr

Used by constant $\psi$ or constant $\varphi$ mode scans.

/r0 = (h, k, l)

/r1 = (h, k, l)

...

/r19 = (h, k, l)

Sets the i$th$ reflection of the UB-matrix to $hkl$ and the current angular position.

/range_chi=float_expr

/range_omega=float_expr

/range_phi=float_expr

/range_two_theta=float_expr

Used from scan/reflection. The range of the individual angular scans, also used as the start range for the automatic centering.

/reflex_count=int_expr

Number of valid reflections. Normally set by the scan/reflection menu.

/rk$i$=float_expr $i$ $\in$ [1,3]

The reciprocal lattice constants.

/rw$i$=float_expr $i$ $\in$ [1,3]

The reciprocal lattice angles.

/scan_mode=int_expr [1,3]

Selects one of the following conditions:

0 - Bisecting 1 - Fixed $\psi$ 2 - Constant plane mode

/ub$ij$=float_expr $i,j$ $\in$ [1,3]

The UB matrix elements. The UB matrix is used to transform a q-vector to the laboratory frame and vice verse (coded by Th. Brückel).

/ub_a_la_dif4

The UB matrix is calulated using Klaus Eichhorns (Uni Karlsruhe) refinement algorith.

/ub_from_two

The UB matrix is calulated using the first 2 reflections (and the lattice).

/ub_to_lattice

Calculates the lattice parameters from the UB matrix.