LIGO Clean and Bake Methods and Procedures

Notes and Changes:: v26: Posted Feb 2025 by Calum Torrie. Refer to v25 for full list of updates. v25: Previous list of full updates. v24-v1: refer to previous revisions.

Pending Updates:
(0) Somehow Titanium is not called out here. It is approved as per E960050 and has been through bakes already as per: https://ics.ligo-la.caltech.edu/JIRA/browse/Bake-12849. Titanium (clean / bake as SSTL).

(1) Alumina grade 99 or 98 (like these spacers, D1102007) - C&B as SSTL i.e. 200 deg C (but no ultrasonic).

(2) Add Material Datasheets - https://www.morgantechnicalceramics.com/en-gb/datasheets/material-datasheets/

(3) Question on sapphire processing e.g. sapphire balls - process as SSTL (not as sapphire prisms).

(4) Review sapphire prisms callout??

(5) (i) PARTS START AS GOLD PLATED BERYLIUM COPPER Material from Accu-Glass https://www.accuglassproducts.com/specialty-connectors/push-line-connectors/line-0072 (ii) As such wear gloves at all times when handling, wash parts with soap and water to remove any residual dust. (iii) Locally do not machine, these parts are made from Beryllium copper. Discuss material with vendor if asking to machine. (iv) BeCu SDS attached to D2400279.

Source doc: https://docs.google.com/document/d/1VJpxPFlaEPhA_iOG3o3b25K5RG5gYYRi/edit

(6) We had issues with rusting on free-machining grades of stainless steel. See https://services1.ligo-la.caltech.edu/FRS/show_bug.cgi?id=36538 for some details. Tried "AMS 2700 Method 2" for passivation of rusting stainless and followed up with an airbake at 120C. Part surface finish had a dramatic visual improvement. Suggested: In only glass containers (aka non-metallic), 135F +/- 5F solution of 50% Citranox and 50% DI water [7.5% +/- 2.5% citric acid] for 10 minutes, aggressive DI water rinse, then load into a cold airbake oven, ramp up to 120C and hold for 1hr or 2hr at most to reform chrome oxide layer. E.g. don't put even borosilicate labware in a hot 120C oven; start from cold to not have a shatter risk. 3 hours at 120C seemed to over-oxide the parts slightly.

Related Documents:

Referenced by:

LIGO Document E960022-v26

LIGO Clean and Bake Methods and Procedures