Recent Results of NICT Caesium Atomic Fountains

National institute of information and communications technology (NICT) has developed Cs atomic fountain frequency standards aiming at contributing to improve the accuracy of International Atomic Time (TAI) and Japan Standard Time. They are called NICT-CsF1 and NICT-CsF2. The accuracy evaluation of CsF1 has been completed and a type B uncertainty of 1.9times10^-15 has been achieved. NICT-CsF2 is under development.