| The 110 trapping geometry is used, and the fountain will operate with two cold caesium atom clouds in flight simultaneously. |
| Their frequency has been checked by direct comparison with a caesium clock in the Time section, in collaboration with P. Moussay. |
| This guarantees that there is no lead, cadmium and caesium 134 and 137 or that if there is, it is below the detection threshold. |
| The University of Southampton used mass spectrometry to probe samples for plutonium, radium and caesium. |
| By using the very basis of matter, we can define the second to be 9,192,631,770 ticks of the caesium clock. |
| The same cannot be said of logarithms or the reactivity of caesium. |
