Kyle Beloy

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Black-body radiation (BBR) shift is an important systematic correction for the atomic frequency standards realizing the SI unit of time. Presently, there is a controversy over the value of the BBR shift for the primary 133 Cs standard. At room temperatures the values from various groups differ at 3 × 10 −15 level, while the modern clocks are aiming at 10(More)
Atomic clocks have been instrumental in science and technology, leading to innovations such as global positioning, advanced communications, and tests of fundamental constant variation. Timekeeping precision at 1 part in 10(18) enables new timing applications in relativistic geodesy, enhanced Earth- and space-based navigation and telescopy, and new tests of(More)
The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for(More)
Microwave atomic clocks are based on the intrinsic hyperfine energy interval in the ground state of an atom. In the presence of an oscillating electric field, the atomic system—namely, the hyperfine interval—becomes perturbed (the ac Stark effect). For the atomic sample in a clock, such a perturbation leads to an undesired shift in the clock frequency and,(More)
The dual-kinetic-balance (DKB) finite basis set method for solving the Dirac equation for hydrogen-like ions [V.M. Shabaev et al., Phys. Rev. Lett. 93 (2004) 130405] is extended to problems with a non-local spherically-symmetric Dirac–Hartree–Fock potential. We implement the DKB method using B-spline basis sets and compare its performance with the(More)
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