Jack Disciacca

The pursuit of low noise in optical instruments for areal surface topography measurement is relevant to many surface types, ranging from super-polished optical surfaces to weakly reflecting or scattering textures that require enhanced signal sensitivity. We clarify the definition and experimental methods for quantifying random noise in areal surfac...

Coherence scanning interferometry (CSI) is widely used for surface topography characterisation. With the ability to measure both rough surfaces with the high slopes and optical finishes, CSI has made contibutions in fields from industrial machining to optical fabrication and polishing [1,2]. While the low coherence sources for CSI are typically bro...

The surface topography of metal additive manufactured (AM) parts can be challenging to measure due to the presence of complex features, such as high slopes, step like recesses and protuberances, and local variations in reflectance. Recent innovations in coherence scanning interferometry (CSI) technology, such as high dynamic range of exposure and a...

Surface topography measurement for metal additive manufacturing (AM) is a challenging task for contact and non-contact methods. In this paper, we present an experimental investigation of the use of coherence scanning interferometry (CSI) for measurement of AM surfaces. Our approach takes advantage of recent technical enhancements in CSI, including...

Additive manufacture (AM) of metal components is a rapidly maturing technology; but given the large number of interrelated process parameters, it remains difficult to control to high precision. It has been observed that processing conditions may be associated with specific features in the surface texture [1], creating a drive to achieve fast, and r...

We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the post-expansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions,...

We demonstrate a novel atom chip trapping system that allows the placement and high-resolution imaging of ultracold atoms within microns from any <100 um-thin, UHV-compatible material, while also allowing sample exchange with minimal experimental downtime. The sample is not connected to the atom chip, allowing rapid exchange without perturbing the...

Previous measurements with a single trapped proton (p) or antiproton (p̄) detected spin resonance from the increased scatter of frequency measurements caused by many spin flips. Here a measured correlation confirms that individual spin transitions and states are rapidly detected instead. The 96% fidelity and an efficiency expected to approach unity...

\DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace} \DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace} \DeclareRobustCommand{\mup}{$\mu_{p}${}{}\xspace} \DeclareRobustCommand{\mupbar}{$\mu_{\pbar}${}{}\xspace} \DeclareRobustCommand{\muN}{$\mu_N${}{}\xspace For the first time a single trapped \pbar is used to measure the \pbar magnetic m...

The CPT theorem predicts the same properties of matter and anti-matter, however, in the nearby Universe, we observe a huge imbalance of matter and antimatter. Therefore, it is intriguing to measure the properties of particles and antiparticles in order to contribute to an explanation of this phenomena. In this article, we will describe the experime...

The proton magnetic moment in nuclear magnetons is measured to be $\mu_p/\mu_N \equiv g/2 = 2.792\,846 \pm 0.000\,007$, a 2.5 ppm (parts per million) uncertainty. The direct determination, using a single proton in a Penning trap, demonstrates the first method that should work as well with an antiproton as with a proton. This opens the way to measur...

Using scaled-energy Stark spectroscopy, we report the observation of recurrences due to closed orbits, both geometric and diffractive, in the ν=0, R=1, nd Rydberg series of H2 (16<n<26) interacting with the ν=0, R=3 series (13<n<15). The data support the molecular closed-orbit theory prediction of diffractive trajectories due to inelastic scatterin...

The first one-proton self-excited oscillator (SEO) and one-proton feedback cooling are demonstrated. In a Penning trap with a large magnetic gradient, the SEO frequency is resolved to the high precision needed to detect a one-proton spin flip. This is after undamped magnetron motion is sideband-cooled to a 14 mK theoretical limit, and despite rando...

We report the observation of an electric quadrupole transition between the 4s{sup '}[1/2]â{sup o} and 3d[3/2]â{sup o} states in the spectrum of argon and use it in the first step of a scheme to excite Rydberg states. The initial identification of the transition is based on one-color, two-photon photoionization. A different experiment utilizing two-...

Recently, Rydberg states have been shown to be present in the plasma of an Argon glow discharge [1]. Properties of Rydberg states in electric fields contribute to the overall behavior of the ion-electron plasma, converting, for example, free electrons into Rydberg electrons and vise verse. We are investigating the role of Rydbergs in low-temperatur...