Per patch 5.7 Charged Matter Transubstantiator was added to the weekly mission rewards.

http://www.swtor.com/patchnotes/1232018/game-update-5.7

The following changes are being made to the Solo PvP Ranked Weekly Mission:

Mission will reward 250 Unassembled Components (up from 200)

Mission will reward 1,000 Ranked Season 9 Tokens as intended (up from 0)

Mission now also rewards 3 Charged Matter Transubstantiators

Now after patch 5.8 it's no longer there. Go to PvP terminal pick up Solo Ranked Weekly