Total ionization dose radiation tests results of the epoch timing system with sub-picosecond resolution and stability for its applications in space missions.

We report on the concept, design, and tests of a New Picosecond Event Timer (NPET) device and its response to the total ionizing dose. These radiation tests aimed to verify that the existing version of the NPET device may be used in space missions. The device was subjected to radiation of a total dose of 74 Gy provided by a Co source. The epoch timing part of the device was not detectably affected by the radiation dose. After the radiation dose, the epoch timing of single measurement resolution is better than 0.9 ps with the overall timing stability characterized by Time Deviation being better than 5 fs for averaging times of 100 s. The completed device tests and results indicate the possibility of using the existing version of the New Pico Event Timing device electronics for a space mission in which the total radiation dose will not exceed 74 Gy value.