# Running TRICS with a Single Counter

In this mode TRICS simulates a conventionell four circle diffractometer much like a x-ray diffractometer as commercially available. The tasks which have to be solved are:

- Locate Reflections
- Index reflections and refine a UB-matrix.
- Measure a couple of reflections.
- Furthermore there are some specialities.

### Locate Reflections

If you know x-ray single crystal diffractometers you'll expect sophisticated reflection search procedures here. Little is available in this field in SICS. It was deemed inapropriate for neutron research. The first reflections must be found by hand. Something which may help in this is a quick scan facility which allows to run a motor and print counts while the motor is moving. This can be invoked by a command like this:

    susca var start end time

The parameters are:

- var: the motor or variable to scan.
- start: the start position from which to scan.
- end: the end position for this scan.
- time: The maximum counting time.

Be aware that this is inprecise and liable to changes in the source current. But it may help to locate the aproximate position of a peak.

Once a peak has been found, its position can be optimised and centered with the peak optimiser. Dor not forget to put all collimators in and to close all slits before optimizing. This is in order to improve accuracy.

Once one reflection has been located, others might be located using the conescan method when the lattice constants are known. Do not forget to open all slits and to remove all collimators for this.

If two reflections and the cell constants are known, a provisional UB matrix may be calculated with the UBCALC module. UBCALC can also calculate the UB matrix from three reflections from scratch.

With a prvisional UB matrix determined it is advisable to locate and optimise another 20 reflections in order to do UB matrix refinement. During this time, reflections may be stored using the rliste module:

rliste clear
  clears all entries from the list
rliste store
  saves the current diffractometer position into the list
rliste write file
  Writes the contents of the reflection list to the file specified.

### Indexing Reflections and Refining UB-Matrix

For these purposes the external programs INDEX and RAFIN are provided. These programs are courtesy of the ILL, France.

### Measuring Reflections

Before measuring reflections a list of reflections to measure must be created. This is done with the external program HKLGEN. Then reflections this reflection list can be fed into SICS using the mess command. mess creates two output files: a .col file containing the reflection profiles of all the relfections and a .dat files which contains the HKL,F,sig(F),TH,OM,CH,PH for each reflection. Intensity has then be integrated within SICS. The .col files can be processed by the program REFRED which allows to perform more advanced data reduction chores and has a choice of integration methods for reflection data. Please note, that SICS does not automatically measure standard reflections. It is your task to add suitable standard reflections into the reflection list.

## Special Commands

As of current this section only holds the hklscan commmand which allows to express a scan in Miller indizes. This is in fact a scan in reciprocal space.