LIGO Document E1100784-v8

Initial Alignment Procedure - LHAM4 and LHAM5 As Built

Document #:
Document type:
E - Engineering documents
Other Versions:
This is the procedure for the initial alignment of the Livingston HAM4 and HAM5. This document describes the necessary equipment and procedures for setting the initial positions and the angular alignments of the principal optics both for the cartridge installation on the test stand and the later installation of the cartridge into the chamber.
Notes and Changes:
23/5/2014 J. Oberling: Updated figures, various cross reference/format fixes.

19/11/2013 J. Oberling: Since this alignment is completed the As Built document is getting its own version.

6/28/2013 J. Oberling: Updated to v6 to include below specs in document and add As Built document.

Monuments extended out to y = -27000.

4/26/2013 D. Coyne: The positional and angular alignment accuracy requirements set forth in T0800307-v6 are based upon 10% of the OSEM range, the criteria used in iLIGO. However, for aLIGO, we can tolerate using more of the DC range of the OSEMs, say 30% to 40%. Using this revised criteria the requirements for SR2 alignment (for example) are as follows (see notes filed for T0800307-v6):
6.2.4 SR2 vertical: +/- 3.4 mm
6.2.5 SR2 horizontal: +/- 5.1 mm
6.2.8 SR2 yaw: +/- 820 microrad
6.2.9 SR2 pitch: +/- 520 microrad
This procedure should be changed to reflect this relaxation in the alignment accuracies for SR2, as well as similar relaxed alignment accuracies for the other SRC optics (see notes for T0800307-v6)

5/3/2013 D. Coyne: Similarly for SR3 and SRM, but where the decentering (vertical & horizontal) is limited by diffraction (clipping) considerations:

6.3.3 SR3 vertical: +/- 3.0 mm
6.3.4 SR3 horizontal: +/- 3.0 mm
6.3.6 SR3 yaw: +/- 200 microrad
6.3.7 SR3 pitch: +/- 560 microrad

6.4.3 SRM vertical: +/- 3.0 mm
6.4.4 SRM horizontal: +/- 4.6 mm
6.4.6 SRM yaw: +/- 820 microrad
6.4.7 SRM pitch: +/- 520 microrad

where the section references above are to sections within the LHAM4 & LHMA5 alignment procedure (E1100784-v5).

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