First results of PTB's atomic caesium fountain

At PTB an atomic caesium fountain was constructed. Ramsey fringes with a FWHM of 0.86 Hz were obtained by launching the atoms to a height of 83 cm above the cooling region. A first measurement of the magnetic field homogeneity yields 0.33 nT (rms), only 0.16% of the mean value of 0.205 /spl mu/T. First frequency comparisons with a hydrogen maser show promising results.