Difference between revisions of "Mirror prototype test plan"
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After the mirror box removal, the following tests should be performed to study the damage to the mirrors | After the mirror box removal, the following tests should be performed to study the damage to the mirrors | ||
* Water/food dye leak check | * Water/food dye leak check | ||
− | ** Initial spot check with dye for clear leak sources | + | ** Initial spot check with food dye for clear leak sources: nothing observed |
− | ** Submerge full mirror piece in water tank with dyed water to identify possible leak sources | + | ** Submerge full mirror piece in water tank with fluorescent dyed water to identify possible leak sources: [https://logbooks.jlab.org/entry/3859248 done] |
* Relative reflectivity mirror measurement | * Relative reflectivity mirror measurement | ||
** Compare reflectivity of know sample mirror and those from mirror box similar to [https://logbooks.jlab.org/entry/3704904] | ** Compare reflectivity of know sample mirror and those from mirror box similar to [https://logbooks.jlab.org/entry/3704904] | ||
− | ** Further studies could be done in detector group's Big Blue Box, etc. | + | ** Further studies could be done in detector group's Big Blue Box, etc. |
− | == | + | == Planned prototypes == |
− | Small samples ~( | + | Small samples ~(2x2 in) 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:''' | '''Supplies needed:''' | ||
− | * Clear DP270 and applicators | + | * Clear DP270 and applicators |
− | * Epotek301-2 and 301-2FL epoxy (ordered by Mark) | + | * Epotek301-2 and 301-2FL epoxy (ships on 12/8) |
− | * | + | * Hostility slury polish (ordered by Mark) |
− | * Glass/mirror pieces (cut | + | * Wipe-on screen protector |
− | ** | + | * Glass/mirror pieces (cut at Danny's glass) |
− | ** | + | ** 20 pieces of 2x2 in standard glass samples for testing epoxy application processes |
− | ** | + | ** 20 pieces of 2x2 in borosilicate glass for prototypes |
− | * Bell jar from detector group | + | ** 23 pieces of 2x2 in UVE mirrors for prototypes |
+ | * Bell jar from detector group | ||
* "Bag" for pumping on glass/mirror sandwich (Keith re-assemble in Hall) | * "Bag" for pumping on glass/mirror sandwich (Keith re-assemble in Hall) | ||
=== Wider epoxy seal === | === Wider epoxy seal === | ||
Follow similar procedure as existing mirror box, but use wider strip to provide better water 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 | + | * Borosilicate + UVE mirror with DP270 1-2 cm wide strip around edge |
'''Notes:''' | '''Notes:''' | ||
* Some mirrors were successfully sealed in existing mirror box, what is unique about them? | * 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. | * 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. | ||
+ | * [https://logbooks.jlab.org/entry/3859248 Results from the dye test] show that a the corners are particularly likely to fail with small strip of epoxy | ||
− | === Full epoxy === | + | === Full epoxy sandwich === |
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 | 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 sandwich with DP270 entirely between surfaces | ||
* Borosilicate + UVE mirror with Epotek301-2 entirely between surfaces | * Borosilicate + UVE mirror with Epotek301-2 entirely between surfaces | ||
− | === | + | === Poured epoxy layer === |
− | Use bell jar from detector group to pump | + | Use bell jar from detector group to pump out bubbles |
* UVE mirror with Epotek301-2 poured on and cured over ~days under bell jar to investigate procedure | * 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 | * UVE mirror with Epotek301-2FL poured on and cured over ~days under bell jar to investigate procedure | ||
'''Notes''': | '''Notes''': | ||
− | * | + | * Requires level surface for even curing of "flat" coating of Epotek |
+ | * Requires clean room or to cure without contamination | ||
* Consider solutions for "dam" around mirror to keep fixed thickness of epoxy | * Consider solutions for "dam" around mirror to keep fixed thickness of epoxy | ||
+ | * Could we consider a spray-on application if the epoxy has low enough viscosity? | ||
− | === Screen protector === | + | === Molded epoxy layer === |
− | Stephanie suggested an off the shelf wipe-on screen protector. | + | Bobby and Keith made some silicone molds that could be used to maintain a thin epoxy layer on the mirror surface [https://logbooks.jlab.org/entry/3859252] |
+ | * UVE mirror with Epotek301-2 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 and custom sized mold | ||
+ | |||
+ | === Screen protector (liquid glass) === | ||
+ | Stephanie suggested an off the shelf wipe-on screen protector. | ||
* UVE mirror with screen protector applied | * UVE mirror with screen protector applied | ||
+ | |||
+ | === Rear surface mirror === | ||
+ | Keith identified a possible vendor for high reflectivity rear-surface mirror of large size | ||
+ | * Considering 5 mm thickness, will need samples to measure reflectivity | ||
+ | * Seal rear surface of mirror with 3M strips and silicone(?) against aluminum strongback | ||
== Test plan == | == Test plan == | ||
− | After prototypes are produced (early December), make the following tests: | + | After prototypes are produced (by early December), make the following tests: |
# measure reflectivity relative to control UVE mirror | # measure reflectivity relative to control UVE mirror | ||
+ | # for one control sample of each prototype, measure the wavelength dependence in the Big Blue Box | ||
# use laser to evaluate impact of any non-uniformity of epoxy layers (speckling) | # use laser to evaluate impact of any non-uniformity of epoxy layers (speckling) | ||
# place one sample in water bath and one sample under UV lamp to test stability | # place one sample in water bath and one sample under UV lamp to test stability |
Latest revision as of 13:48, 7 December 2020
Contents
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 food dye for clear leak sources: nothing observed
- Submerge full mirror piece in water tank with fluorescent dyed water to identify possible leak sources: done
- 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.
Planned prototypes
Small samples ~(2x2 in) 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
- Epotek301-2 and 301-2FL epoxy (ships on 12/8)
- Hostility slury polish (ordered by Mark)
- Wipe-on screen protector
- Glass/mirror pieces (cut at Danny's glass)
- 20 pieces of 2x2 in standard glass samples for testing epoxy application processes
- 20 pieces of 2x2 in borosilicate glass for prototypes
- 23 pieces of 2x2 in UVE mirrors for prototypes
- Bell jar from detector group
- "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 1-2 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.
- Results from the dye test show that a the corners are particularly likely to fail with small strip of epoxy
Full epoxy sandwich
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
Poured epoxy layer
Use bell jar from detector group to pump out bubbles
- 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:
- Requires level surface for even curing of "flat" coating of Epotek
- Requires clean room or to cure without contamination
- Consider solutions for "dam" around mirror to keep fixed thickness of epoxy
- Could we consider a spray-on application if the epoxy has low enough viscosity?
Molded epoxy layer
Bobby and Keith made some silicone molds that could be used to maintain a thin epoxy layer on the mirror surface [2]
- UVE mirror with Epotek301-2 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 and custom sized mold
Screen protector (liquid glass)
Stephanie suggested an off the shelf wipe-on screen protector.
- UVE mirror with screen protector applied
Rear surface mirror
Keith identified a possible vendor for high reflectivity rear-surface mirror of large size
- Considering 5 mm thickness, will need samples to measure reflectivity
- Seal rear surface of mirror with 3M strips and silicone(?) against aluminum strongback
Test plan
After prototypes are produced (by early December), make the following tests:
- measure reflectivity relative to control UVE mirror
- for one control sample of each prototype, measure the wavelength dependence in the Big Blue Box
- use laser to evaluate impact of any non-uniformity of epoxy layers (speckling)
- place one sample in water bath and one sample under UV lamp to test stability
- 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