A bead on a hoop rotating about a horizontal axis: a 1-D ponderomotive trap

We describe a simple mechanical system that operates as a ponderomotive particle trap, consisting of a circular hoop and a frictionless bead, with the hoop rotating about a horizontal axis lying in the plane of the hoop. The bead in the frame of the hoop is thus exposed to an effective sinusoidally-varying gravitational field. This field's component along the hoop is a zero at the top and bottom. In the same frame, the bead experiences a time-independent centrifugal force that is zero at the top and bottom as well. The system is analyzed in the ideal case of small displacements from the minimum, and the motion of the particle is shown to satisfy the Mathieu equation. In the particular case that the axis of rotation is tangential to the hoop, the system is an exact analog for the rf Paul ion trap. Various complicating factors such as anharmonic terms, friction and noise are considered. A working model of the proposed system has been constructed, using a ball-bearing rolling in a tube along the outside of a section of a bicycle rim. The apparatus demonstrates in detail the operation of an rf Paul trap by reproducing the dynamics of trapped atomic ions and illustrating the manner in which the electric potential varies with time.Comment: Second external review for AJP, 28 pages double spaced, 11 figure

Planar Ion Trap Geometry for Microfabrication

We describe a novel high aspect ratio radiofrequency linear ion trap geometry that is amenable to modern microfabrication techniques. The ion trap electrode structure consists of a pair of stacked conducting cantilevers resulting in confining fields that take the form of fringe fields from parallel plate capacitors. The confining potentials are modeled both analytically and numerically. This ion trap geometry may form the basis for large scale quantum computers or parallel quadrupole mass spectrometers. PACS: 39.25.+k, 03.67.Lx, 07.75.+h, 07.10+CmComment: 14 pages, 16 figure

Assessing the impact of ergonomic manipulators on the cursor control

The analysis of the ergonomic mice efficiency for the cursor movement is presented based on the experiments with both self-reported parameters and biometric measurements. The adequacy of choice as well as the overall speed and physical load are examined

T-junction ion trap array for two-dimensional ion shuttling, storage and manipulation

We demonstrate a two-dimensional 11-zone ion trap array, where individual laser-cooled atomic ions are stored, separated, shuttled, and swapped. The trap geometry consists of two linear rf ion trap sections that are joined at a 90 degree angle to form a T-shaped structure. We shuttle a single ion around the corners of the T-junction and swap the positions of two crystallized ions using voltage sequences designed to accommodate the nontrivial electrical potential near the junction. Full two-dimensional control of multiple ions demonstrated in this system may be crucial for the realization of scalable ion trap quantum computation and the implementation of quantum networks.Comment: 3 pages, 5 figure

Повышение уровня энергоэффективности процесса синтеза аммиака на основе разработки динамической модели процесса

Аміак є одною з неорганічних хімічних речовин з найвищою часткою виробництва в світі. Процес синтезу аміаку є енергозатратним та потребує детального аналізу. Такий аналіз є можливим та безпечним за допомогою моделювання процесу. Дана стаття розглядає моделювання реактору синтезу аміаку та виконання експерименту над моделлю. Модель є динамічною, що дозволяє краще зрозуміти процес синтезу при раптовій зміні параметрів процесу.Ammonia is one of the inorganic chemicals with the highest production rate in the world. The process of ammonia synthesis has a high energy consumption and requires detailed analysis. Such an analysis is feasible and safe using simulation of the process. This paper examines the simulation of the ammonia synthesis reactor and the experiment on the model. The objective of this paper is to develop the basis for a synthesis reactor monitoring tool that can be used to identify the margin to blow-out with respect to current load, catalyst activity, pressure and temperature. For this purpose system dynamics is studied by means of the dynamic modelling. The model is dynamic, and this allows better understanding of the synthesis process in case of the sudden change of the operating parameters.Аммиак является одним из неорганических химических веществ с высокой долей производства в мире. Процесс синтеза аммиака является энергозатратным и требует детального анализа. Такой анализ возможен и безопасен при помощью моделирования процесса. Данная статья рассматривает моделирование реактора синтеза аммиака и выполнения эксперимента над моделью. Модель является динамической, что позволяет лучше понять процесс синтеза при внезапном изменении параметров процесса

Archival ethics: The truth of the matter

This essay explores the question of whether records professionals are as aware of the ethical dimensions of their work as they should be. It consider first the historical and professional context of archival ethics, then examines a recent case about business archives involving the author that suggests the need for renewed attention to professional ethics, and concludes with a discussion about how archivists might reconsider the ethical dimensions of their work

Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap

Miniaturized ion trap arrays with many trap segments present a promising architecture for scalable quantum information processing. The miniaturization of segmented linear Paul traps allows partitioning the microtrap in different storage and processing zones. The individual position control of many ions - each of them carrying qubit information in its long-lived electronic levels - by the external trap control voltages is important for the implementation of next generation large-scale quantum algorithms. We present a novel scalable microchip multi-segmented ion trap with two different adjacent zones, one for the storage and another dedicated for the processing of quantum information using single ions and linear ion crystals: A pair of radio-frequency driven electrodes and 62 independently controlled DC electrodes allows shuttling of single ions or linear ion crystals with numerically designed axial potentials at axial and radial trap frequencies of a few MHz. We characterize and optimize the microtrap using sideband spectroscopy on the narrow S1/2 D5/2 qubit transition of the 40Ca+ ion, demonstrate coherent single qubit Rabi rotations and optical cooling methods. We determine the heating rate using sideband cooling measurements to the vibrational ground state which is necessary for subsequent two-qubit quantum logic operations. The applicability for scalable quantum information processing is proven.Comment: 17 pages, 11 figure

Ion Trap Networking: Cold, Fast, and Small *

A large-scale ion trap quantum computer will require low-noise entanglement schemes and methods for networking ions between different regions. We report work on both fronts, with the entanglement of two trapped cadmium ions following a phase-insensitive Molmer-Sorensen quantum gate, the entanglement between a single ion and a single photon, and the development of advanced ion traps at the micrometer scale, including the first ion trap integrated on a semiconductor chip. We additionally report progress on the interaction of ultrafast resonant laser pulses with cold trapped ions. This includes fast Rabi oscillations on optical S-P transitions and broadband laser cooling, where the pulse laser bandwidth is much larger than the atomic linewidth. With these fast laser pulses, we also have developed a new method for precision measurement of excited state lifetimes. ION ENTANGLEMENT Local ion entanglement Laser-addressed trapped ions with qubits embedded in long-lived internal hyperfine levels hold significant advantages for quantum information applications One such algorithm is Grover's searching algorithm which searches an unsorted database quadratically faster than any known classical searc