Instrument preparation before the first measurement

Before you can start with your first data aquisition be aware of a few things. For running a measurement you need at least to run two programs: the SANS status display (sansstatus &) and the command line client (sics &). After connecting both clients to the SANS server and authorizing the command line client at the server with user privileges you are ready to change the instrument set-up. The initial step at the beginning of your measurement are the following:

1. Check if beam is closed, if not than do it now.

2. Set the experiment informations via the dialog box [New Experiment].

3. Define the directory, where you intend to store your batch files with batchroot /data/lnsg/<username>[/<batchdir>] resp. with exe batchpath /data/lnsg/<username>[/<batchdir>].

4. Choose the needed instrument settings like sample detector distance, collimation, wavelength, etc.

5. Adjust the beam stop by performing the following steps:

   • Move in an attenuator with an attenuation factor larger than 100.

   • Put a strong forward scatterer into the beam, e.g. teflon

   • Center the beam stop roughly by the SICS command bs x 0 y 0.

   • Open the beam.

   • Use the command banana preset 1000 and banana count to start an aquisition without storing the result.

   • Adjust the beam stop with the bs-command.

   • After each beam stop movement you can reset the histograming memory of the detector by banana initval 0.

   • Remove the attenuator.

   • Perform a fine adjustment of the beam stop with an unattenuated beam if neccessary.

   • Stop the data aquisition by pressing the [Interrupt] button in the lower left corner of the command line client.