Progress Towards a Transportable and High-Accuracy Sr + Ion Clock at NRC

We are developing a transportable 88Sr+ ion clock for frequency comparisons with optical clocks in remote laboratories. Accuracy limitations found in the current NRC laboratory system, most notably the uncertainties related to the blackbody radiation shift and the collisional frequency shifts, should be significantly reduced in the new system. The expected total systematic fractional frequency uncertainty of the device approaches the 10−18 level.