Quantum Metrology Triangle Experiments: A Status Review

Quantum Metrology Triangle experiments combine three quantum electrical effects (the Josephson effect, the quantum Hall effect and the single-electron transport effect) used in metrology. These experiments allow important fundamental consistency tests on the validity of commonly assumed relations between fundamental constants of nature and the quantum electrical effects. This paper reviews the history, results and the present status and perspectives of Quantum Metrology Triangle experiments. It also reflects on the possible implications of results for the knowledge on fundamental constants and the quantum electrical effects.Comment: 36 pages, 8 figure

G0^0 Electronics and Data Acquisition (Forward-Angle Measurements)

The G$^0$ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for $\vec{e}p$ elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G$^0$ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G$^0$ forward-angle measurements.Comment: 35 pages. 17 figures. This article is to be submitted to NIM section A. It has been written with Latex using \documentclass{elsart}. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment In Press (2007

Single-electron current sources: towards a refined definition of ampere

Controlling electrons at the level of elementary charge $e$ has been demonstrated experimentally already in the 1980's. Ever since, producing an electrical current $ef$, or its integer multiple, at a drive frequency $f$ has been in a focus of research for metrological purposes. In this review we first discuss the generic physical phenomena and technical constraints that influence charge transport. We then present the broad variety of proposed realizations. Some of them have already proven experimentally to nearly fulfill the demanding needs, in terms of transfer errors and transfer rate, of quantum metrology of electrical quantities, whereas some others are currently "just" wild ideas, still often potentially competitive if technical constraints can be lifted. We also discuss the important issues of read-out of single-electron events and potential error correction schemes based on them. Finally, we give an account of the status of single-electron current sources in the bigger framework of electric quantum standards and of the future international SI system of units, and briefly discuss the applications and uses of single-electron devices outside the metrological context.Comment: 55 pages, 38 figures; (v2) fixed typos and misformatted references, reworded the section on AC pump

G0 electronics and data acquisition (forward-angle measurements)

The G0 parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross-section was measured for elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required to measure the few-part-per-million asymmetry, the G0 experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics, processing only a small fraction of the events, was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events from the 128 detector pairs at a mean rate of 2 MHz per detector pair with low deadtime and with minimal helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G0 forward-angle measurements

The ampere and the electrical units in the quantum era

By fixing two fundamental constants from quantum mechanics, the Planck constant $h$ and the elementary charge $e$, the revised Syst\`eme International (SI) of units endorses explicitly quantum mechanics. This evolution also highlights the importance of this theory which underpins the most accurate realization of the units. From 20 May 2019, the new definitions of the kilogram and of the ampere, based on fixed values of $h$ and $e$ respectively, will particularly impact the electrical metrology. The Josephson effect (JE) and the quantum Hall effect (QHE), used to maintain voltage and resistance standards with unprecedented reproducibility since 1990, will henceforth provide realizations of the volt and the ohm without the uncertainties inherited from the older electromechanical definitions. More broadly, the revised SI will sustain the exploitation of quantum effects to realize electrical units, to the benefit of end-users. Here, we review the state-of-the-art of these standards and discuss further applications and perspectives.Comment: 78 pages, 35 figure

Conductive Textiles and their use in Combat Wound Detection, Sensing, and Localization Applications

Conductive textiles, originally used for electromagnetic shielding purposes, have recently been utilized in body area network applications as fabric antennas and distributed sensors used to document and analyze kinematic movement, health vital signs, or haptic interactions. This thesis investigates the potential for using conductive textiles as a distributed sensor and integrated communication system component for use in combat wound detection, sensing, and localization applications. The goal of these proof-of-concept experiments is to provide a basis for robust system development which can expedite and direct the medical response team in the field. The combat wound detection system would have the capability of predicting the presence and location of cuts or tears within the conductive fabric as a realization of bullet or shrapnel penetration. Collected data, along with health vitals gathered from additional sensors, will then be wirelessly transmitted via integrated communication system components, to the appropriate medical response team. A distributed sensing method is developed to accurately predict the location and presence of textile penetrations. This method employs a Wheatstone bridge and multiplexing circuitry to probe a resistor network. Localized changes in resistance illustrate the presence and approximate location of cuts within the conductive textile. Additionally, this thesis builds upon manually defined textile antennas presented in literature by employing a laser cutting system to accurately define antenna dimensions. With this technique, a variety of antennas are developed for various purposes including large data transmission as would be expected from multi-sensor system integration. The fabrication technique also illustrates multilayer antenna development. To confirm simulation results, electrical parameters are extracted using a single-frequency resonance method. These parameters are used in the simulation and design of single-element and two-element wideband slot antennas as well as the design of a wideband monopole antenna. The monopole antenna is introduced to an indoor ultra-wideband (UWB) localization system to illustrate the capability of pinpointing the wearer of textile antennas for localization applications. A cavity-backed dog-bone slot antenna is developed to establish the ability to incorporate conductive vias by sewing conductive thread. This technique can be easily extrapolated to the development of textile substrate integrated waveguide (SIW) technologies

Muon spin precession frequency extraction and decay positron track fitting in Run 1 of the Fermilab Muon g - 2 experiment

One of the few indications for new physics is the discrepancy between the theoretical and experimental values for the anomalous magnetic moment of the muon. There is a discrepancy of 3 to 4 standard deviations between theory and the last experimental measurement made at Brookhaven National Laboratory in 2001, which measured the muon magnetic anomaly a to 540 parts per billion (ppb). This discrepancy has been consistent for many years with ever improving theoretical calculations. In order to resolve or confirm this discrepancy experiment E989, Muon g - 2, is underway to measure a to 4 times higher precision at 140 ppb. In Run 1 E989 gathered its first production data, consisting of approximately 8 × 10^9 decay positrons above an energy threshold of 1.7 GeV. This dissertation describes the experimental measurement, the detectors, the precession frequency extraction, and the track fitting of decay positrons in Run 1. The track fitting is done using a ^2 minimization algorithm to fit tracks propagated within a Geant4 reconstruction simulation including error propagation. The precession frequency is extracted using an analysis technique called the Ratio Method. The Ratio Method takes the ratio of time-shifted decay positron spectra in order to remove the decay exponential along with slowly varying effects in the data. Precession frequency extraction analyses for four near-final Run 1 datasets are presented with full systematic error evaluations. The total Run 1 precession frequency error determined in this analysis is 469.4 ppb, where the error is statistics dominated. Combined with the expected error in the magnetic field measurement of 140 ppb, the expected final error on a for Run 1 of E989 is (500 ppb), comparable to the previous measurement

Enhancements of a three dimensional target model for deep ground penetrating radar systems

Both commercial and military industries incorporate the use of Ground Penetrating Radar (GPR). In the case of the military, a stationary object, such as a bunker or tunnel, can be detected. Even high-resolution, three-dimensional (3D) and twodimensional (2D) imagery of energy reflected by the target and its surrounding environment can be produced. This is accomplished using multiple scene perspectives inherent in advanced Synthetic Aperture Radar (SAR) techniques. Although underground target detection can be successful, the return data, usually suffers a significant degree of signal degradation due to the ground medium and target composition. A valid theoretical target model must account for adverse affects such as specular and diffuse reflections, dispersion and attenuation in order to provide an accurate representation of the simulated GPR scenario. It is the aim of this thesis to demonstrate the benefits of a high fidelity GPR target model. Demonstrated in the model is the ability to record estimative return power as a function of multiple variables including frequency, target depth, target composition, ground medium, complex antenna patterns, and transmitted power. Using ray-tracing, a bidirectional reflectance distribution function (BRDF), and 3D geometric analysis, the specular and diffuse reflective and refractive sub-surface energy interactions known to take place for a spatially complex target are simulated. Results culminate in the comparison of 3D and 2D imagery generated using this target model with imagery generated using previous models