1 / 14

CLEANLINESS ISSUES FOR ADVANCED LIGO INSTALLATIONS Doug Cook

CLEANLINESS ISSUES FOR ADVANCED LIGO INSTALLATIONS Doug Cook. LSC MEETING – MARCH 2006. The Following Advisories are based on Experiences, Improvements and Techniques Learned and Developed from Initial LIGO Installations.

vin
Download Presentation

CLEANLINESS ISSUES FOR ADVANCED LIGO INSTALLATIONS Doug Cook

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CLEANLINESS ISSUES FOR ADVANCED LIGO INSTALLATIONSDoug Cook LSC MEETING – MARCH 2006 LIGO - G060050-00-W

  2. The Following Advisories are based on Experiences, Improvements and Techniques Learned and Developed from Initial LIGO Installations. • Recommendations are given with a “what's practical and reasonable” line of thinking. LIGO - G060050-00-W

  3. Cleanliness Requirements/Improvements for Advanced LIGO Installations • ‘Travelers’ to control and record material processes like cleaning parts, vacuum baking and their RGA scans. Travelers should be maintained with the assembly procedures during builds. Travelers will then be filed with the DCC. • Lab Air Handling - Increase the use of HEPA panels, soft wall enclosures and laminar flow benches with ion bars. • HVAC system to maintain a positive pressure and flow. (No current controllable humidity on HVAC system). • Lab Maintenance – Restrict access, use regular cleaning cycles (janitorial). • Proper use of clean room garb, clean room practices and contamination controls. • Material Handling - proper handling, transportation and storage of components waiting vacuum installation. LIGO - G060050-00-W

  4. Cleanliness Requirements/Improvements for Advanced LIGO Installations • Vent Preparations: LVEA and VEAs - Restrict access, increase regular cleaning cycles (janitorial). • Minimal gowning of frocks, caps and shoe covers to enter LVEA and VEAs. • Continuously monitor particle counts from 2 locations. Maintain cleanliness in LVEA to produce counts of less than 100 per average count of 5microns with activities (class 100). • LVEA and VEA - HVAC should be producing a positive pressure and air flow. • Chamber Vents: Single isolatable volume vents due to purge air limitations (200 scfm total capacity with 50 scfm available to each isolatable volume). • Wipe down chambers from top to bottom prior to door removal. • Install additional soft wall enclosure over chamber openings and seal. • Wet mop floor under soft wall enclosure just prior to pulling door. • Door remains mounted until particle counts under soft wall enclosures read “zero”. • If possible only remove a single door per chamber and cover opening with fitted soft cover. • When overhead crane is used for BSC dome removal or SUS installations utilize soft cover socks to seal crane shedding. • Use additional HEPA soft wall enclosures for gowning. • Use a laminar flow benches for staging Class ‘A’ & ‘B’ components. LIGO - G060050-00-W

  5. Working inside the Vacuum Vessels • Carefully plan vent and follow an approved Installation Specification. • Minimize chamber tourism. • Minimize non “Class” ‘A’ hardware in side. • Minimize time spent inside. • Adhere strictly to established contamination controls. • Change garb frequently. LIGO - G060050-00-W

  6. Purge Lines 50 scfm per isolated volume through 2” line. 200 scfm total capacity through 4” line LIGO - G060050-00-W

  7. Nomenclature for Airborne Particle Concentration • “Class 10” (at 0.5um) describes air with not more than 10 particles / cu. ft. of size 0.5 um and larger. • “Class 100” (at 0.5um) describes air with not more than 100 particles / cu. ft. of size 0.5 um and larger. LIGO - G060050-00-W

  8. LVEA Particle Counts with HVAC Air Flow Reduced by 50% LIGO - G060050-00-W

  9. With the HVAC Flow Reduced 50% the Wind has Substantial Effects 3 days of wind Tuesday Maintenance LIGO - G060050-00-W

  10. H1-ITMx Replacement Particle Counts In situ Counts are suspiciously high. Perhaps due to having the cloth cover vertical and next to the input port of the particle counter. LIGO - G060050-00-W

  11. BSC Soft Wall Enclosure with Crane “Sock” 14 HEPA Filters. Fans with variable speeds. Approximate 16,800 scfm max. Started up 3 days before vent. LIGO - G060050-00-W

  12. HAM Soft Wall Enclosure 20 HEPA Filters. Fans with variable speeds. Approximate 20,000 scfm max. Started up 3 days before vent. LIGO - G060050-00-W

  13. Auxiliary Clean Room Used to cover BSC door openings. Also used as change rooms for gowning up. Used over work benches and for clean staging areas. 4,800 scfm capacity LIGO - G060050-00-W

  14. Improvements to Investigate • Possible use of “Air Showers” (R. DeSalvo). • Add more HEPA filtered panels to clean air near to vented volume. • Breathing and body temperature controls. (Hard to work with) • Establish a more user friendly vacuum cleaner for in situ work. • Establish better static controls. • Test Burlington C3 fitted covers for particles. • Omit (Al) wrapping much of the installation hardware by using cleanable hardware. • Better understanding of particle counter installations and calibrations. Maximize their use. LIGO - G060050-00-W

More Related