ePIC pfRICH mechanical design mailing list

["Kiselev, Alexander" <ayk AT bnl.gov>]

  Dear All,

  let's discuss this in the 1pm meeting today. I'd strongly recommend using the same material as was used for the sPHENIX TPC, unless we want to face situations like suction does not suffice, etc down the road.

  Cheers,

    Alexander.

---

From: Wenliang Li <wenliang.b.li AT gmail.com>
Sent: Monday, December 11, 2023 8:05 AM
To: Alex Eslinger <eslinger AT jlab.org>; eic-projdet-pfrich-mechanical-design-l AT lists.bnl.gov <eic-projdet-pfrich-mechanical-design-l AT lists.bnl.gov>
Cc: wenliang.billlee AT gmail.com <wenliang.billlee AT gmail.com>; Kiselev, Alexander <ayk AT bnl.gov>; Thomas Hemmick <thomas.hemmick AT stonybrook.edu>; Garg, Prakhar <prakhar.garg AT yale.edu>
Subject: Re: Latest Prototype STEP

 

Dear Alex and Dan,

Just communicated with Tom, and we think the 0.25mm Carbon Fiber is
strong enough and carries the benefit of reducing the material budget in
the electron-going direction.

If possible, we would recommend using the 0.25mm Carbon fiber sheet
(same as the TPC).

Of course, you have the final call and we will adapt accordingly.
(Especially if you think the thicker Carbon Fiber sheet could carry
extra benefit in terms of structural integrity).

Many thanks

Bill

On 12/10/23 11:56, Wenliang Li wrote:
> Also, just to completely making sure I am not inventing the numbers in
> my head,
>
> please see the original PO for the carbon fiber purchase for the TPC.
>
> Many thanks
>
> Bill
>
>
> On 12/10/23 11:36, Wenliang Li wrote:
>> Hi Alex,
>>
>> After double-checking the dimensions, I found a small discrepancy
>> that could change the pfRICH ring design.
>>
>> The issue is the thickness of the carbon fiber sheet.
>>
>> My understanding is that the current design uses the old TPC carbon
>> fiber thickness which is 0.25mm, therefore the outer diameter of the
>> ring should be 1299.50mm.
>>
>> In the latest CAD step file, I see 0.56mm as the carbon fiber wall
>> thickness, which gives the outer diameter of the ring of 1298.88, see
>> figure below:
>>
>> Without talking to the carbon fiber vendor, I don't know if 0.56mm
>> thick is a standard catalog item. I will check with them first thing
>> tomorrow morning. But I assume, 0.5mm should be since 0.25 was used
>> for the TPC.
>>
>> The question here is that is 0.5mm carbon fiber sheet is too rigid to
>> form a circle.
>>
>> From your end, could you and Dan confirm the thickness?
>>
>> Many thanks
>>
>> Bill
>>
>>
>>
>>
>> On 12/7/23 11:13, Alex Eslinger wrote:
>>> Good morning,
>>>
>>> I've attached the latest prototype STEP to this email (specifically
>>> for SBU) but also for anyone else's use. This has the updated
>>> 120-bolt pattern with ¼-20 bolts instead of M5 and the end ring
>>> profile as 0.75" x 1". The mirror designs have not been fully
>>> finalized as I'm trying to get a meeting with Andy to discuss them.
>>>
>>> Thanks,
>>> Alex
>>>