One of my lab colleagues has asked me to repair a piece of equipment. It's some kind of X-ray device, but the issue with it is at a high-voltage section. There was some arcing, so the wiring needs to be repaired. The voltage is 12.5 kV, and it comes in via a double-insulated coaxial cable (with insulation on the outside and inside between the shield and the conductor). At the end of the conductor is a flag terminal that's also insulated. However, in the original wiring, the coaxial shield was exposed and connected to a ground wire connected to the chassis. This exposed part was covered up with heat shrink, so after that, all that's left is the inner insulation and the high-voltage conductor. I was wondering if this is the proper way to run the cable, have the high-voltage part not be surrounded by the cable shield (even though there's insulation around the conductor). If not, what is the proper way to splice a cable in this case?