What are specs of this MagSafe wire, and what is its purpose? I need to repair a MagSafe power adapter, which has a damaged cable. 

As you can see in the photos, there is damage to what appears to be shielding.


  Update: This frayed wire is not “shielding.” See the accepted answer and its comments for details.





I’m leery of simply applying (more ugly, ineffective) tape as a long term option. I’m considering using some higher quality shrink-wrap or the like, but I‘d also like to account for the fraying. 

The problem is, I cannot find any information online about the frayed part, such as the material and the function(s) it provides. 

Can you provide detailed specifications of the frayed part of the cable, including how it works / what it does?

Presumably, I can use the answer to inform my repair decisions. 

Of course, I also welcome comments you might have about how to or whether to repair this damage.
There are two cables that come out of the adapter (white brick) - a white cable and a bare cable (it's actually black on the very end of the cable at the adapter end).  The bare cable wraps around the white cable.  White being positive 18V and and black being ground.

Can you repair this?  

Yes.  However it will involve destroying the case of the adapter because it's held together with adhesive.  I did this once and had to reassemble it with duct tape.  However, instead of fixing the cable, replacements can be had relatively inexpensively on eBay.  

However, I highly suggest getting a new adapter because the case will never quite close properly and you run the risk of breaking the plastic because the adhesive is so strong.  If you do get a new adapter, get a genuine Apple and not a knock-off.