Identify the origin of near-zero signal pixels at high bias

Identify the physical origin of the population of IBEX pixels whose correlated-double-sampling signal falls close to zero at pixel biases of 10.5 V and 12.5 V, in order to reduce the associated outlier fraction in subsequent detector versions.

Background

The fraction of 3-sigma outlier pixels increases with pixel bias, reaching 8.2% at 10.5 V and 11.8% at 12.5 V. At these two highest biases, an additional population of pixels appears with signals close to zero.

The paper reports that the cause of this population is unresolved. Determining its origin is necessary to understand the bias-dependent operability degradation and to guide improvements to future IBEX detectors.