Pumpdown and Ultimate Pressures (PSI document V049-1-078, rev 0)

Document #:

LIGO-E1400012-v1

Document type:

E - Engineering documents

Abstract:

Pumpdown and Ultimate Pressures calculated by PSI for Initial LIGO.

Files in Document:

• E1400012-v1 Pumpdown and Ultimate Pressures (PSI docum...pdf (7.1 MB)

Other Files:

• HAM and BSC CHAMBER INTERNAL VOLUME.pdf (780.6 kB)

Topics:

• Vacuum

Authors:

• Dennis Coyne

Notes and Changes:

Pumpdown and Ultimate Pressures (PSI document V049-1-078, rev 0). I think that this was one of the documents within the PSI document collection V049-1-097, CDRL No. 03. Note that the volumes are different for aLIGO in the vertex and diagonal sections due to the larger diameter and longer input and output sections:

Section	iLIGO volume (m^3)	aLIGO volume (m^3)	reference
BSC Chamber	27.2	27.2	SolidWorks, compare to 31.67m^3 in V049-1-078,rev 0
HAM Chamber	10.4	10.4	SolidWorks, compare to 11.26m^3 in V049-1-078,rev 0
LLO End	56	56	V049-1-078, rev 0
MC Tubes	10.89	99.25	iLIGO: V049-1-078,rev0 (2) MC tubes ea 12m long & 0.76m dia aLIGO: 2 MC tubes ea 13.7m long & 2.15m dia
LLO Corner	380	468	iLIGO: V049-1-078, rev 0 aLIGO: iLIGO estimate revised with aLIGO MC estimate

The SolidWorks volume calculations for the chambers should be more accurate than the PSI-V049-1-078,rev0 estimates. Note that the overall vacuum volume size estimates above have not been changed to reflect the SolidWorks calculations -- as a result the vacuum volume estimates may be ~10% higher than actual.