Novel High Voltage Cryogenic Breaks

The US Department of Energy (DOE) is actively seeking to develop new and improved Cryogenic High Voltage Breaks (CHVBs) that are used to electrically isolate cryogenic devices and equipment (e.g., accelerator magnets, fusion energy magnets, electrical power equipment, etc.) operating at High Voltages (HV) from nearby grounded components and structures (e.g., cryogenic piping and refrigeration). CHVBs not only must withstand extremely high electric field stresses while operating leak tight at cryogenic temperatures, CHVBs also have stringent mechanical, electrical, thermal, magnetic, and radiation tolerance requirements that must also be met. State-of-the-art ceramic CHVBs operating at Vop < 100 kV are notoriously unreliable and when repeatedly thermal cycled, prone to frequent micro-cracking and hence leaking. Furthermore, for operating voltages > 100 kV and/or possessing a non-magnetic signature there are NO suitable commercial product alternatives and hence new CHVB designs are needed to overcome inherent design flaws that limit their operational performance. Our proposed Phase II effort addresses three technology gaps in existing ceramic CHVBs: a) the long-term reliability issue caused by micro- cracking due to repeated thermal cycling, b) CHVBs that can operate in both atmosphere and vacuum environments at Vop > 100 kV, and c) non-magnetic CHVB solutions. In this Phase II proposal, Energy to Power Solutions (e2P), Argonne National Laboratory (ANL), and Oak Ridge National Laboratory (ORNL) will use the a technical approach to CHVB design and fabrication that will be split into two distinct sections: a)Vop > 100 kV and b) Vop < 100 kV. E2P addresses in this proposal non-magnetic CHVBs with Vop > 100 kV and needed for HV machines such as ATLAS and CARIBU at ANL and ORNL-SNS (see letters of support) as well as the design and fabrication methods for CHVBs with Vop < 100 kV in which to improve overall CHVB performance and most importantly reliability, while simultaneously lowering fabrication costs.