The Mott transition as a cause of anomalies on spacecraft

In the Mott transition, an insulator with a critically high donor density undergoes a sudden transition to become a conductor. On the other hand, it is known that sufficiently high electric fields applied to dielectrics at ordinary charge densities can cause breakdown. The author conjectures that the critical donor density can be lowered by applying high electric fields to the insulators. Using a simple model encompassing the concepts of Debye, Poole, and Frenkel, the author has obtained a continuous curve connecting the two critical points, viz., critical density and critical field. The motivation of this work is spacecraft anomalies. They briefly review the circumstances of the most notable spacecraft failures in recent years. Although the true causes of the failures are probably system design specific and will probably never be known, it is likely that the failures were due to breakdowns or discharges in semiconductors or dielectrics. Irradiated dielectrics and semiconductors have defects and dangling bonds playing the role of donors. High electric fields are built by electrons deposited inside the dielectrics. With the use of the curve obtained, it is concluded that the insulator-conductor transition can occur at lower donor densities and lower electric fields than previously thought.