Related papers: Enhanced Dynamical Stability with Harmonic Slip-st…
This paper considers hybrid beamforming (HB) for downlink multiuser massive multiple input multiple output (MIMO) systems with frequency selective channels. For this system, first we determine the required number of radio frequency (RF)…
The phenomenon of frequency and phase synchronization in stochastic systems requires a revision of concepts originally phrased in the context of purely deterministic systems. Various definitions of an instantaneous phase are presented and…
We demonstrate two fully and tightly phase locked 750 MHz ytterbium (Yb) fiber frequency combs that are independently stabilized to a continuous wave (CW) laser with <1 rad RMS phase error. A bulk EOM and a single stack PZT are separately…
Barrier rf buckets have brought about new challenges in longitudinal beam dynamics of charged particle beams in synchrotrons and at the same time led to many new remarkable prospects in beam handling. In this paper, I describe a novel beam…
Deploying massive number of antennas at the base station side can boost the cellular system performance dramatically. Meanwhile, it however involves significant additional radio-frequency (RF) front-end complexity, hardware cost and power…
Even the most regular stick-slip frictional sliding is always stochastic, with irregularity in both the intervals between slip events and the sizes of the associated stress drops. Applying small-amplitude oscillations to the shear force, we…
High-stability quartz oscillators are needed in a number of space applications. A short-term stability of parts in 10^{-14} [Allan deviation \sigma y(\tau) ] is sometimes required, for integration time \tau of approximately 1-10 s. The…
The dynamic localization of a two-level atom in a periodic potential under the action of spin-orbit coupling and a weak harmonically-varying linear force is studied. We consider optical and Zeeman potentials that are either in-phase or…
We present a compact laser frequency stabilization method by locking a 556 nm laser to a high-precision wavelength meter. Unlike traditional schemes that rely on optical cavities or atomic references, we stabilize the laser frequency via a…
The Fermilab Main Injector accelerating cavities have sparking issues when they are run at voltages higher than those required by the PIP-II project. This is a problem Fermilab is working on as planning begins for the next upgrade to the…
Optical frequency combs, coherent light sources that connect optical frequencies with microwave oscillations, have become the enabling tool for precision spectroscopy, optical clockwork and attosecond physics over the past decades. Current…
We demonstrate the suppression of parametric instability using through optical actuation in an electro-optical feedback loop, stabilising the high order optical mode content in an 80 metre long Fabry-Perot cavity. The loop suppression of…
Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied science, from measurements of fundamental constants and searches for dark…
We demonstrate a frequency synchronization scheme with the phase noise compensation function placed at the client site. One transmitting module hence can be linked with multiple client sites. As a performance test, using two separate 50 km…
A progogype 5-GHz 500-kW CW klystron (model E3762 provided by Toshiba Electron Tubes & Devices Co. Ltd.) has been operating as the RF source for the lower hybrid current drive (LHCD) system in the KSTAR tokamak. In order to investigate how…
Quantifying frictional properties of interfaces remains a major challenge in both terrestrial and extraterrestrial geomechanics, where available samples, laboratory apparatuses, and geophysical observations are inherently limited. We…
We present two ultra-stable lasers based on two vibration insensitive cavity designs, one with vertical optical axis geometry, the other horizontal. Ultra-stable cavities are constructed with fused silica mirror substrates, shown to…
In Fermilab's PIP-II machine protection system, beam loss signals from various detectors are digitized at 125 MS/s. Noise from both high-frequency sources and low-frequency 60 Hz AC power equipment can contaminate the data. To suppress…
Gravitational-wave detectors use state-of-the-art quantum technologies to reduce the noise induced by vacuum fluctuations, via injection of squeezed states of light. Future detectors, such as Einstein Telescope, may require the use of two…
The development of magnetic cogging is part of the Fermilab Booster upgrade within the Proton Improvement Plan (PIP). The Booster is going to send 2.25E17 protons/hour which is almost double the present flux, 1.4E17 protons/hour to the Main…