Abstract: The physics part is the frequency discriminator for the rubidium atomic clock, which determines its stability specifications including the short term and long term stability specifications(above 1 second). In physics part, the rubidium metal, glass and ferronickel are adopted, and some bipolar transistors and operational amplifiers are also adopted, the kernel componentrubidium bulb, was especially manufactured by a special vacuum technology. So the low dose rate sensitivity for these materials, devices and technology is essential to be estimated. The radiation experiment by low dose rate was advanced for the physics part of the rubidium atomic clock and the rubidium bulb used in it. The radiation source is Co⁶⁰ γ, the dose rate is 0.01rad(Si)/s, and the total dose is 50krad(Si). This work realistically simulates the ionization damage for these products, and the results will be referenced for the rubidium atomic clocks in the orbit and be useful to the radiation harden design for the later rubidium atomic clocks.

Key words: Rubidium atomic clock, Physics part, Rubidium bulb, Low dose rate, Ionization radiation