• CLIO
• AutoAlignmentScripts

Auto Alignment Script

This page explains the automatic alignment script. It resides in /cvs/cds/kami/scripts/AutoAlignment/

Working Principle

The dither alignment technique uses a sinusoidal signal to move a mirror in pitch or yaw. By demodulating the transmitted power signal at the same frequency as the excitation signal, we can obtain an error signal of misalignment.

Implementation

There are three parties involved in the dither alignment. The first one is the realtime code, which does the excitation and demodulation. Then the demodulated signal is read by a python script called DitherAlignment.py. This script feedback the error signal to corresponding Picomotors by writing appropriate values to EPICS PVs which are monitored by pmepics.py. The daemon script pmepics.py is responsible to drive Picomotors according to the values of the EPICS PVs reserved for Picomotors.

AIS realtime code

AIS is an acronym for Alignment Initialization System.