[Dsg-reflectivity] [EXTERNAL] Re: October 10, 2023 UV reflectivity test station meeting minutes

[Zhiwen Zhao]

Dear Tyler

It sounds like good progress and both meeting slots work for me.

Bill and Anselm know more about new mirrors to be tested.
But you always start by testing the two mirrors I gave you last summer. 
(One mirror with known reflection as calib and the other with unknown 
reflection)

Zhiwen

On 1/8/2024 1:52 PM, Tyler Lemon wrote:
> Hi Anselm and Bill,
> 
> Yes, we have received the parts for the UV measurement tests.
> 
> We have a UV lamp, UV rated optical fibers, a collimator, and optics for 
> the "re-collector" for getting light back in to a fiber. I also got a 
> small integrating sphere and UV rated photodiode. The remaining thing to 
> figure out for the tests is how to hold the optics in the correct 
> orientation. I started looking into it and designed/3D-printed a 
> prototype stand for the components, but haven't been able to test much 
> beyond that.
> 
> Currently, I'm available from 8:30AM - 1:30PM on January 18 and January 
> 19 for a meeting, so just let me know what time works for everyone.
> 
> Do you have any more information on the timeline for the tests? 
> Particularly, is there a time frame that we're expecting mirrors at JLab 
> that need to be tested?
> If there is some time constraint, please let us know so we can work the 
> task into our schedule.
> 
> Thanks!
> 
> -Tyler
> 
> 
> 
> 
> ------------------------------------------------------------------------
> *From:* Wenliang Li <wenliang.b.li at gmail.com>
> *Sent:* Saturday, January 6, 2024 9:12 AM
> *To:* Anselm Vossen, Ph.D. <anselm.vossen at duke.edu>; Tyler Lemon 
> <tlemon at jlab.org>
> *Cc:* dsg-internal <dsg-internal at jlab.org>; Zhiwen Zhao 
> <zwzhao at jlab.org>; Matthew McEneaney <matthew.mceneaney at duke.edu>
> *Subject:* [EXTERNAL] Re: October 10, 2023 UV reflectivity test station 
> meeting minutes
> 
> Hi Tyler and all,
> 
> I completely agree with Anselm's suggestion.
> 
> I will be at JLab from the 18th -21st, if possible, we could have the 
> coated samples double-checked by Tyler's setup during this time.
> 
>  From the reflectivity measurement that was performed in December, the 
> best of the coated samples at SBU was around 70-75% reflective at 300 
> nm.  We are currently compiling a report documenting our findings which 
> will be circulated to everyone shortly. We are currently taking steps in 
> upgrading our coating capability for further improvements.
> 
> Many thanks
> 
> Bill
> 
> On 1/6/24 09:05, Anselm Vossen, Ph.D. wrote:
>> As I said, I am very interested to get my student involved (btw: We'll
>> also have a PD stationed at JLab starting in February, but I am not sure
>>   if he will get involved, maybe it makes sense...)