Mirror prototype test plan

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Testing of existing mirror box

After the mirror box removal, the following tests should be performed to study the damage to the mirrors

  • Water/food dye leak check
    • Initial spot check with dye for clear leak sources
    • Submerge full mirror piece in water tank with dyed water to identify possible leak sources
  • Relative reflectivity mirror measurement
    • Compare reflectivity of know sample mirror and those from mirror box similar to [1]
    • Further studies could be done in detector group's Big Blue Box, etc.

Proposed prototypes

Small samples ~(5x5 cm) should be made for testing under water and reflectivity measurements. Below are the suggested fabrication steps to produce test pieces. For reproducibility we could make 3 of each sample. All these should be tested with standard glass pieces prior to using borosilicate and UVE mirror.

Supplies needed:

  • Clear DP270 and applicators (stock room items?)
  • Epotek301-2 and 301-2FL epoxy (ordered by Mark)
  • Spray on screen protector (Tim provides information to Mark?)
  • Glass/mirror pieces (cut by Keith or Danny's glass?)
    • ~15 pieces of 5x5 standard glass samples for testing epoxy application processes
    • ~15 pieces of 5x5 borosilicate glass for prototypes
    • ~20 pieces of 5x5 UVE mirrors for prototypes
  • Bell jar from detector group (Tim request from Brian Cross?)
  • "Bag" for pumping on glass/mirror sandwich (Keith re-assemble in Hall)

Wider epoxy seal

Follow similar procedure as existing mirror box, but use wider strip to provide better water seal

  • Borosilicate + UVE mirror with DP270 2 cm wide strip around edge

Notes:

  • Some mirrors were successfully sealed in existing mirror box, what is unique about them?
  • Concern about how we get such a thick ring of epoxy around the edge with the previous "wicking" approach of putting a bead on the outside and let it seep between the two layers. Could bevel the edge of the protective glass to provide larger sealing surface to apply epoxy.

Full epoxy

Setup small "bag" with blue film to sandwich protective glass against mirror surface using pump. Keith previously setup something like this in the Hall last year

  • Borosilicate + UVE mirror sandwich with DP270 entirely between surfaces
  • Borosilicate + UVE mirror with Epotek301-2 entirely between surfaces

Epoxy layer

Use bell jar from detector group to pump

  • UVE mirror with Epotek301-2 poured on and cured over ~days under bell jar to investigate procedure
  • UVE mirror with Epotek301-2FL poured on and cured over ~days under bell jar to investigate procedure

Notes:

  • This requires level surface for even curing of "flat" coating of Epotek
  • Consider solutions for "dam" around mirror to keep fixed thickness of epoxy

Screen protector

Stephanie suggested an off the shelf wipe-on screen protector. Tim found a spray on version as well that may be easier to apply

  • UVE mirror with screen protector applied

Test plan

After prototypes are produced (by early December), make the following tests:

  1. measure reflectivity relative to control UVE mirror
  2. for one control sample of each prototype, measure the wavelength dependence in the Big Blue Box
  3. use laser to evaluate impact of any non-uniformity of epoxy layers (speckling)
  4. place one sample in water bath and one sample under UV lamp to test stability
  5. each week, take samples out of water/lamp setups and measure relative reflectivity

Goal: decide on full scale prototypes to produce by the end of 2020 for testing in December/January