Search results for "gase"
showing 10 items of 1216 documents
Design of a compact diode laser system for dual-species atom interferometry with rubidium and potassium in space
2017
We report on a micro-integrated high power diode laser based system for the MAIUS II/III missions. The laser system features fiber coupled and frequency stabilized external cavity diode lasers (ECDL) for laser cooling, Bose-Einstein condensate (BEC) generation and dual species atom interferometry with rubidium and potassium on board a sounding rocket.
A method for the quantitative study of atomic transitions in a magnetic field based on an atomic vapor cell with L=lambda
2008
We describe the so-called "Lambda-Zeeman method" to investigate individual hyperfine transitions between Zeeman sublevels of atoms in an external magnetic field of 0.1 mT - 0.25 T. Atoms are confined in a nanocell with thickness L = Lambda, where Lambda is the resonant wavelength (794 nm or 780 nm for D1 or D2 line of Rb). Narrow resonances in the transmission spectrum of the nanocell are split into several components in a magnetic field; their frequency positions and probabilities depend on the B-field. Possible applications are described, such as magnetometers with nanometric spatial resolution and tunable atomic frequency references.
AC Stark shift noise in QND measurement arising from quantum fluctuations of light polarization
2004
In a recent letter [Auzinsh {\it{et. al.}} (physics/0403097)] we have analyzed the noise properties of an idealized atomic magnetometer that utilizes spin squeezing induced by a continuous quantum nondemolition measurement. Such a magnetometer measures spin precession of $N$ atomic spins by detecting optical rotation of far-detuned probe light. Here we consider maximally squeezed probe light, and carry out a detailed derivation of the contribution to the noise in a magnetometric measurement due to the differential AC Stark shift between Zeeman sublevels arising from quantum fluctuations of the probe polarization.
Probabilities, States, Statistics
2016
In this chapter we clarify some important notions which are relevant in a statistical theory of heat: The definitions of probability measure, and of thermodynamic states are illustrated, successively, by the classical Maxwell-Boltzmann statistics, by Fermi-Dirac statistics and by Bose-Einstein statistics. We discuss observables and their eigenvalue spectrum as well as entropy and we calculate these quantities for some examples. The chapter closes with a comparison of statistical descriptions of classical and quantum gases.
<title>Collisional and thermal ionization of sodium Rydberg atoms in single and crossed atomic beams</title>
2006
The results of the experimental and theoretical study on associative ionization of laser excited Na Rydberg atoms in collisions with ground-state atoms and on thermal ionization by blackbody radiation in single and crossed effusive atomic beams are reported and discussed.
Investigation of Space-Charge Phenomena in Gas-Filled Penning Traps
2009
The centering of ions in Penning traps by a quadrupolar radiofrequency excitation in the presence of a buffer gas has been studied in the regime of high charge‐densities. It is found to deviate significantly from the single‐particle situation. In particular, the efficiency of the cooling process is affected as well as the resolving power. The behavior has been studied experimentally at the preparation trap REXTRAP and the high‐precision Penning trap setup ISOLTRAP both located at the on‐line mass separator ISOLDE at CERN. In addition, the phenomenon has been investigated numerically by a custom‐designed simulation.
The trapping condition and a new instability of the ion motion in the ion cyclotron resonance trap
1995
Abstract In analogy to the critical mass, m crit , a critical voltage, U crit , (and a general trapping parameter, π trap ) is defined, above which the ion motion in an ion cyclotron resonance (ICR) trap is unstable and the ions are lost from the trap. The theoretical values for the critical voltage are confirmed by experimental results. Singly charged gold cluster ions, Au n − , of several sizes, n = 50, 60, 76, 100, 110, and 145 (the latter corresponding to an ion mass of 28 560 u), were injected into an ICR trap, stored, and detected by axial ejection and single ion counting using a microchannel plate detector. During the storage period the trapping voltage, U , was varied for extended d…
Semi-empirical supercell calculations for free- and bound-hole polarons in crystal
1997
Two different parametrizations of the semi-empirical method of the intermediate neglect of the differential overlap (INDO) are applied to the calculations of the small-radius hole polarons in the corundum crystal. The 80-atom supercell has been used for the study of the atomic and electronic structure of a free small-radius hole polaron (the self-trapped hole, STH) and a hole polaron bound by a Mg impurity (the so-called centre), respectively. Both parametrizations indicate that the two-site (quasi-molecular) configurations of both kinds of polaron have the lowest energy (which does not exclude the existence of one-site polarons also characterized by considerable relaxation energies). For c…
Self-trapped exciton formation through photo-induced recombination of F and H centers in alkali iodides
1997
The photo-induced conversion of the primary F, H center pairs into self-trapped excitons have been proposed and studied in alkali iodides.
Chiral symmetry breaking condensates from baryonic sum rules
1984
We analyse baryonic sum rules in order to determine chiral symmetry breaking condensates. We especially investigate the influence of the choice of the interpolating field and of the factorization hypothesis for the four quark condensate. Our results are consistent with those obtained from pseudoscalar sum rules and PCAC.