Crystal extraction: Alignment of crystal with respect to the beam

The program CRYSTAL.BAS allows to calculate the exact alignment of the crystal with respect to thebeam. It is written in QBasic and installed on server USRV_865 connected to the PC network. This note describes how to access and to run this program from any PC which is connected to the network NICE. The angle of the two crystals actually installed has been scanned over a relatively wide range and at different positions with respect to the ideal closed orbit, thereafter referred to as beam center line. The signal (Volt) produced by the position sensitive detectors (PSD) intercepting the reflected laser beams used to monitor the crystal alignment, is plotted in the attached figures.