uhv cleanliness requirements: cleaning/baking and contamination control
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UHV Cleanliness Requirements: Cleaning/Baking and Contamination Control. Dennis Coyne HAM-SAS Bidder’s Conference @ LIGO Laboratory, Caltech 25 October 2005. Livingston, LA. Hanford, WA. Basic UHV Compatibility Requirements. Cleanliness Requirements: - PowerPoint PPT PresentationTRANSCRIPT
LIGO R&D 1G050557-00
UHV Cleanliness Requirements:UHV Cleanliness Requirements:Cleaning/Baking and Contamination Cleaning/Baking and Contamination
ControlControl
Dennis Coyne
HAM-SAS Bidder’s Conference@ LIGO Laboratory, Caltech
25 October 2005
Livingston, LA
Hanford, WA
LIGO R&D 2G050557-00
Basic UHV Compatibility Requirements
Cleanliness Requirements:» Achieve a Non-Volatile Residue (NVR) level of A/50 or better (per MIL-STD-
1246C or IEST-STD-CC1246D) on piece parts before clean assembly» Achieve a Particulate Cleanliness Level of 50 or better (per MIL-STD -
1246C or IEST-STD-CC1246D) on piece parts before clean assembly» Perform clean assembly and all steps through UHV Packaging in a Class
100 Clean Room (per FED-STD-209)» Comply with Contamination Control Protocols defined in E048228
(M990034 is also a good guide)» Package the Clean Parts per E048227
No Virtual Leaks» Full Penetration Welds
No Cold Welding» Stainless fasteners into Aluminum» Silver coated Stainless Fasteners into Stainless» Oversized pilot and tap for tapped holes
LIGO R&D 3G050557-00
Ultra-High Vacuum (UHV) Cleanliness Requirements Related to Manufacturing Processes
RECEIVE/INSPECT
MATERIALS/PARTS
MACHINE PRE-CLEAN
WELD
WIND
INSPECT TUNE
DIS-ASSEMBLE
PRECISIONCLEAN
AIR BAKEFTIRTEST
“CLEAN”ASSEMBLY(GAS TUNE)
PARTIALDISASSEMBLY
PACKSHIP
MARAGINGHEAT TREAT
STRESSRELIEF
WELDMENTMACHINING
POTTING
INSPECT“DIRTY”
ASSEMBLY -FIT CHECK
UHV COMPATIBLEMACHINING
RESTRICTIONS
UHV COMPATIBLEWELDING
RESTRICTIONS& FULL
PENETRATIONWELD
CERTIFICATION
“GROSSCLEANING” PER
MIL-STD-1246OR E048225
HA
ND
LIN
G/
CO
NT
AM
INA
TIO
NC
ON
TR
OL
PR
OT
OC
OL
FO
RW
IND
ING
S
REASONABLYCLEAN
ENVIRONMENT &HANDLING
“PRECISION CLEANING”PER MIL-STD-1246
OR E048225OR E960026
AIR BAKE PERsection 5.5 ofE970063-01(SIMILAR TO
E990452)
FTIR TEST PER MIL-STD-1246 OR
IEST-STD-CC1246DTO NVR LEVEL A/50
& PARTICULATELEVEL 100
CONTAMINATION CONTROL PERE048228
(REFERENCE M990034)CLASS 100 (PER FED-STD-209)
UHV PACKAGINGPER E048227(REFERENCE
M990034, E960022)
LIGO LAB QUALIFIESCONTRACTOR
CLEANING/BAKING/CONTAMINATION
CONTROL WITH TESTPIECES AND RGA PER
E960022
Notes: (1) The process sequence depicted
here is suggestive, and not meant to be prescriptive.
(2) Loaded GAS Filter, Spring Blades to be Creep Relaxed in Air Bake
LIGO R&D 4G050557-00
Practical UHV Requirements Must pre-clean parts before welding and winding Must clean parts multiple times during fabrication Must thoroughly clean parts!
» “gross” clean with solvents and acids» Mechanical clean (scrub) parts especially tapped holes – multiple times,
with powered rotary tool – during “gross” and “precision” clean steps» “precision” clean with hot, water soluble detergents (steam or hot water
spray) – multiple times» Never let parts dry with detergent» Multiple rinses with Deionized water
Must bake parts (air or vacuum) after “precision” cleaning Must maintain parts in a class 100 clean room
» or keep wrapped in “UHV Foil” and keep in at least a class 10,000 clean area)
» limit exposure, keep wrapped /covered when possible Must Control Contamination with Good Clean Room Practice
» All tools must be cleaned, air baked, wrapped & kept in Class 100 areas» All personnel must wear full clean room garb, including hair net, face mask
and gloves
LIGO R&D 5G050557-00
UHV Requirement References Particulate Level 50 and NVR Level A/50 per MIL-STD-1246C or IEST-STD-
CC1246D Cleaning for UHV Service:
» Contractor is to certify the cleaning and baking process with representative parts to demonstrate 1246 Level 50-A/50
– NVR Level to be confirmed via FTIR (Fourier Transform Infrared analysis)– Particulate level to be confirmed by particle sizing and counting or equivalent
particle area coverage» LIGO Lab will independently assess the contractor’s cleaning/baking process with
representative parts by RGA (mass spectrometer outgassing analysis) per E960022» Guidance: E048225, Process Specification for Ad-LIGO Seismic Isolation System In-
Vacuum Mechanical Elements: Fabrication (includes cleaning) Contamination Control:
» Per E048228, Process Specification for Ad-LIGO Seismic Isolation System In-Vacuum Mechanical Elements: Contamination Control
» Additional Guidance:– M990034, LIGO Contamination Control Plan– FED-STD-209, Airborne Particulate Cleanliness Classes in Cleanrooms and
Clean Zones– ISO-14644, Cleanrooms and controlled environments
[ISO-14644 superceeds FED-STD-209] Packaging:
» Per E048227, Process Specification for Ad-LIGO Seismic Isolation System In-Vacuum Mechanical Elements: UHV Packaging
LIGO R&D 6G050557-00
Clean Room & Gowning Room
HEPA Filter
Gowning Room
Class 100Clean Room
Class 10,000Room
“Sticky” Mat
LIGO R&D 7G050557-00
HAM Chamber Clean Rooms
“Full” Clean Room Dress
Concrete Floor – Cleaned Routinely, not ideal, but serviceable
LIGO R&D 8G050557-00
UHV Foil
Annealed (baked) UHV Aluminum Foil for Wrapping Parts