نتایج جستجو برای: atomic beam

تعداد نتایج: 200561  

2016
G. Grynberg E. Le Bihan M. Pinard

2014 We have observed a unidirectional oscillation in a ring cavity when a sodium atomic vapour interacts with a non resonant pump beam. We have checked that the frequency of the oscillating beam is almost the same as the frequency of the pump beam. We propose a theoretical interpretation of the origin of a two-wave mixing process in an atomic vapour. We show the necessity of a relaxation proce...

2015

Atom interferometry, in which atomic waves are coherently split and later recombined, has been called the Swiss Army knife of atomic physics because of its numerous applications. Atom interferometers can be used to study gravity, observe quantum effects, and measure fundamental constants. However, the spitting of atomic beams has always been a challenging task. Several beam splitters for atoms ...

2008
Alexander Naß Erhard Steffens

The use of gas expansions to generate atomic or molecular beams has become a standard technique in nuclear and hadron physics for the production of polarized ion beams and gas targets. A direct simulation Monte Carlo method was used to understand the processes occurring in an expansion of highly dissociated hydrogen or deuterium gas at low densities. The results were verified in several measure...

Journal: :The Review of scientific instruments 2009
A Denning A Booth S Lee M Amonson S D Bergeson

We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, thi...

Objective: In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC) using the bilinear scaling method.Methods: The measured attenuation coefficient (μm) was compared to a theoretical attenuation coefficient (μt ) using four different CT scanners and an RMI 467 phantom. The effective energy of the CT beam X-rays was calculated, using the aluminu...

Journal: :Anais da Academia Brasileira de Ciencias 2008
Mushtaq Ahmed Daniel V Magalhães Aida Bebeachibuli Stella T Müller Renato F Alves Tiago A Ortega John Weiner Vanderlei S Bagnato

Cesium atomic beam clocks have been the workhorse for many demanding applications in science and technology for the past four decades. Tests of the fundamental laws of physics and the search for minute changes in fundamental constants, the synchronization of telecommunication networks, and realization of the satellite-based global positioning system would not be possible without atomic clocks. ...

2002
L. A. Melnikov

Quantum reflection of an atomic wave from a solid surface is caused by the attractive van der Waals force acting on the atom near the surface. The researchers had previously verified the quantum reflection of a cold neon atomic beam from a silicon surface. In this research they demonstrate the first known reflective atom-optical elements that use natural interaction of a solid surface, or attra...

2005
G. Baum

We have set up an atomic beam of cesium for the study of spin-dependent electron-cesium scattering. The beam is produced by an effusive oven with continuous recirculation of the condensed metal. The beam is optically pumped by circularly polarized light from two laser diodes tuned to the 6 2 S1/2 (F -3) 6 21P3/2 (F' = 4) and 6 2 Sl/2 (F = 4) --, 6 2 P3/2 (F' = 5) transitions, respectively. Near...

Journal: :Physical review. A, General physics 1987
Prentiss Ezekiel

We have continued our precision studies of laser induced stimulated resonance Raman interactions in a sodium atomic beam with emphasis on Ramsey's method of separated oscillatory fields. We observed Raman-Ramsey fringes for a field separation of up to 30 cm, and the data were consistent with theoretical predictions. We have also been investigating the performance of a clock based on this intera...

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