Proof Test Levels for Advanced LIGO Viewports

Document #:

LIGO-E1101226-v5

Document type:

E - Engineering documents

Abstract:

Inert environment, proof testing is required for all brittle, non-metallic materials on the vacuum envelope. This document defines the proof test levels for all of the Advanced LIGO viewports.

Files in Document:

• E1101226-v5 proof test levels - Updated 13 Jan 2026.docx (277.3 kB)
• E1101226-v5 proof test levels - Updated 13 Jan 2026.pdf (537.4 kB)

Other Files:

• E1101226-v5 viewport proof test values - Updated 13 Ja...pdf (249.2 kB)
• E1101226-v5 viewport proof test values - Updated 13 J...xlsx (43.9 kB)
• addendum to E1101226-v3, derivation of time to failure.docx (32.3 kB)
• addendum to E1101226-v3, derivation of time to failure.pdf (128.7 kB)

Topics:

• System Engineering
• Vacuum

Authors:

• Dennis Coyne

Keywords:

viewport proof

Notes and Changes:

-v5: added viewports from new possible vendors, MPFPI (LIGO-C2500228) and Torr Scientific (LIGO-C2500220). also added an appendix detailing the selection of an acceptable failure probability. Note: The new vendor viewports are NOT recommended for use in LIGO until further testing is performed. See note 4 in spreadsheet.

-v4: added CaF2 as a window material (being considered for the CHETA subsystem).

Related Documents:

• LIGO-E010613: Generic Requirements & Standards for Detector Subsystems
• LIGO-T1100346: Design of the Elastomeric Sealed, High Quality, Viewports

Referenced by:

• LIGO-E2400095: VIEWPORT HUB