First observations of enhanced low dose rate sensitivity (ELDRS) in space:One part of the MPTB experiment

Bipolar devices, most notably circuits fabricated with lateral PNP transist ors (LPNP) and substrate PNP transistors (SPNP), have been observed to exhi bit an enhanced low dose rate sensitivity when exposed to ionizing radiatio n. These dose rate sensitive bipolar devices exhibited enhanced degradation of base current in transistors and of input bias current, offset current, and/or offset voltage in linear circuits at dose rates less than 0.1 rd(Si) /s) compared to devices irradiated at dose rates greater than 1 rd(Si)/s). The total dose responses of several bipolar transistors and linear circuits in a space environment are demonstrated to exhibit enhanced degradation co mparable, in magnitude, to ground-based data irradiated at a dose rate of 1 0 mrd(Si)/s indicating that enhanced low dose rate sensitivities (ELDRS) do indeed exist in space.