Example In-Bar Rasnik Images

© 2015 Richard Studley, Brandeis University.
alignment.hep.brandeis.edu

Introduction

The working plan for nSW In-Bar Alignment is for all images to have no fewer than two full code squares in each direction and no fewer than 10 image pixels per Rasnik pixel square. Because of existing inventory we plan to use 120um masks for "short" lines and 170um masks for "long" lines.

Lines used in example images are as follows:

Line Length Lens-CCD distance (mm) Lens-Rasnik distance (mm) Lens Focal Length
Short 435 480 220
Long 468 915 300
Table: Line distances (approximate, red light).

Images

The third image will be very close to the nSW shorter in-bar lines. The sixth image will be very close to the longer nSW lines. You can analyze the .GIF images in LWDAQ by dragging them on to your desktop and opening them normally in LWDAQ.


85 um mask, short distance: ~10 pixels/square.



85 um mask, long distance: ~6 pixels/square.



120 um mask, short distance: ~15 pixels/square. This is the planned short line.



120 um mask, long distance: ~8.5 pixels/square.



170 um mask, short distance: ~21 pixels/square.



170 um mask, long distance: ~12 pixels/square. This is the planned long line.