Solder Channel to Reduce Degradation of Long HTS Cables

Techniques are described that allow for HTS cables to be solder-filled more easily, quickly, and with a reduced degradation to the performance of the HTS in the cable. In particular, a channel within an HTS cable may include a primary channel into which the HTS is arranged, in addition to a secondary channel that provides an increased hydraulic cross-section through which the solder can flow. The secondary channel may be connected to the primary channel (e.g., as a side-channel). If the secondary channel has an opening within the primary channel that is smaller than the HTS material being placed in the primary channel, the HTS material is not at risk of moving into the secondary channel, which can provide a space proximate to the HTS material and the primary channel through which the solder can freely flow.