[Halld-tracking-hw] CDC Straw Tubes

[Fernando J. Barbosa]

Hi Tim,

The straws in pictures 1 and 2 are NOT acceptable.

Best regards,
Fernando




Tim Whitlatch wrote:
> I have taken pictures against a back light of the 3 straw samples 
> Curtis gave me. They can be found at;
>
> http://www.jlab.org/Hall-D/software/wiki/index.php/CDC#Straws
>
> I am trying to get a handle on the requirements for the straws. The 
> first shows the Stone aluminized Kapton with a back light. As can be 
> seen, most is transparent and the lines can be seen in the direction 
> of the wrap. The 2nd is the latest Lamina aluminized mylar. There are 
> some lines that are transparent and some scratches.
> The 3rd is the original Lamina aluminized straw from Last fall 
> (supposedly the same material as the new ones) This is completely 
> solid against the back light.
>
> What is the requirement here?
> Had the kapton straws held up over the past couple of years in the 
> prototype setup?
> Is the original Lamina straw acceptable?
> I just wish to be clear before I get with the Lamina rep on this.
>
> Thanks,
>
>       Tim
>
>
> Curtis A. Meyer wrote:
>> Hi Everyone -
>>
>>        we have finished going through the 252 straws that were sent 
>> to us by Lumina.
>> Other than the scratches that we talked about at the meeting last 
>> week, the straws
>> appear to be pretty good. The final numbers on the mechanical 
>> acceptance are:
>>
>>      186/252 straws are good
>>        28/252 straws were rejected because they were oval. Better 
>> packing in the
>>                    shipping box would probably recover all of these. 
>> This would give
>>                    us an acceptance rate of:
>>      214/252  or 84.9%   and we would need 4120 straws to get 3500.
>>
>>      Of the rejected ones,  19 were rejects due to imperfections in 
>> the straws,
>>      wrapping, glueing, extra crud stuck to them, ..... The remaining 
>> 17 were
>>      bowed beyond the 1/10 inch specification. This appears to be in 
>> the straw
>>      and not due to shipping or packing.
>>
>>       In order to improve the regular shipment, the box containing 
>> the straws probably
>>       needs to be compartmentalized so that there are fewer straws 
>> pressing on each other.
>>       Perhaps a wine-crate like structure that has ~ 40 straws in 
>> each compartment???
>>
>>       The overall biggest issue that we saw was the scratches on the 
>> straws. The vendor did
>> not have that on the original samples that we received (a year ago).
>>
>>     Curtis
>>
>>   
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