Magnetometer suitable for Earth field measurement based on transient atomic response

We describe the development of a simple atomic magnetometer using $^{87}$Rb vapor suitable for Earth magnetic field monitoring. The magnetometer is based on time-domain determination of the transient precession frequency of the atomic alignment around the measured field. A sensitivity of 1.5 nT/$\sqrt{Hz}$ is demonstrated on the measurement of the Earth magnetic field in the laboratory. We discuss the different parameters determining the magnetometer precision and accuracy and predict a sensitivity of 30 pT/$\sqrt{Hz}$Comment: 6 pages, 5 figure

Sub-Doppler resonances in the back-scattered light from random porous media infused with Rb vapor

We report on the observation of sub-Doppler resonances on the back-scattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and the back-scattered light probes it. Some specificities of the observed spectra reflect the transient atomic evolution under confinement inside the pores. Simplicity, robustness and potential miniaturization are appealing features of this system as a spectroscopic reference.Comment: 6 pages, 4 figure

Hubungan Kadar Merkuri (Hg) dengan Profil Darah Pekerja Pertambangan Emas Tradisional di Desa Jendi Kecamatan Selogiri Kabupaten Wonogiri

Background: mercury is neurotoxic substance which can produce some health effect, depends on impact ofduration of exposure and quantity mercury used. Gold miner had a high risk of continously impact which maycause many health disorder, one of them is blood profile interference.The purpose of this reasearch was to know the relationship between mercury concentration in blood with bloodprofile of traditional mining gold worker in Jendi village, Selogiri Sub District, Wonogiri District.Methods: The study design was an analytic observational research. Research subject were whole of workers whowere working in mining gold. Variables in this research were mercury (Hg) in blood and blood profile. Datacollection using interview, observation, and measurement technique. Data would be analyzed using Kendal's Taucorrelation.Result: The results showed that the average of Hg in blood was 7,819 ppb. It was over toxic level (eˆ 5,8 ppb) andaverage blood profile consist of haemoglobin, erythrocyte, leukocyte, platelet, hematocrit, MCV, MCH, andMCHC were 14,771 gr/dl; 4,9536 jt/mmk; 7,5679 rb/mmk; 334,26 rb/mmk; 43,833%, 88,6333 fl; 29,8833 pg;33,6976. Bivariate analysis showed the significant relationship between mercury (Hg) in blood with bloodprofile (amount of leukocyte) p-value 0,017 and rho 0,257.Conclusion: The conclusion of the research was Hg rates in blood had a toxic limit standard so it can change theblood profile (decreased amount of leukocyte). It was recommended for gold miner to used a personal protectiveequipment like mask, lowering smoking habbit, checked-up, and make lots of green area at mining gold

Theoretical study of dark resonances in micro-metric thin cells

We investigate theoretically dark resonance spectroscopy for a dilute atomic vapor confined in a thin (micro-metric) cell. We identify the physical parameters characterizing the spectra and study their influence. We focus on a Hanle-type situation, with an optical irradiation under normal incidence and resonant with the atomic transition. The dark resonance spectrum is predicted to combine broad wings with a sharp maximum at line-center, that can be singled out when detecting a derivative of the dark resonance spectrum. This narrow signal derivative, shown to broaden only sub-linearly with the cell length, is a signature of the contribution of atoms slow enough to fly between the cell windows in a time as long as the characteristic ground state optical pumping time. We suggest that this dark resonance spectroscopy in micro-metric thin cells could be a suitable tool for probing the effective velocity distribution in the thin cell arising from the atomic desorption processes, and notably to identify the limiting factors affecting desorption under a grazing incidence.Comment: 12 pages, 11 figures theoretical articl

Nonlinear atomic spectroscopy inside a random porous medium

International audienceWe studied a novel spectroscopy setup where alkali atoms are infused in random micro-porous glass and the light probing the atoms have a diffuse nature after the propagation in this strong scattering medium

Large deviations for ideal quantum systems

We consider a general d-dimensional quantum system of non-interacting particles, with suitable statistics, in a very large (formally infinite) container. We prove that, in equilibrium, the fluctuations in the density of particles in a subdomain of the container are described by a large deviation function related to the pressure of the system. That is, untypical densities occur with a probability exponentially small in the volume of the subdomain, with the coefficient in the exponent given by the appropriate thermodynamic potential. Furthermore, small fluctuations satisfy the central limit theorem.Comment: 28 pages, LaTeX 2

Fluctuations of Quantum Currents and Unravelings of Master Equations

The very notion of a current fluctuation is problematic in the quantum context. We study that problem in the context of nonequilibrium statistical mechanics, both in a microscopic setup and in a Markovian model. Our answer is based on a rigorous result that relates the weak coupling limit of fluctuations of reservoir observables under a global unitary evolution with the statistics of the so-called quantum trajectories. These quantum trajectories are frequently considered in the context of quantum optics, but they remain useful for more general nonequilibrium systems. In contrast with the approaches found in the literature, we do not assume that the system is continuously monitored. Instead, our starting point is a relatively realistic unitary dynamics of the full system.Comment: 18 pages, v1-->v2, Replaced the former Appendix B by a (thematically) different one. Mainly changes in the introductory Section 2+ added reference