63 research outputs found
Spatiotemporal visualization of the dynamics of absorbing layers in a two-stage atomizer
This paper describes an experimental apparatus for studying the dynamics of the variation of the spatial distribution of the absorbing layers in a two-stage atomizer. An optical system with a telecentric beam, using a diode laser as the radiation source, is proposed and analyzed. The spatiotemporal resolution and the contribution of refraction effects to the resulting absorption pattern are estimated. The dynamics of the evaporation and condensation processes are visualized in a two-stage atomizer of Cd atoms and NaCl molecules
CIRCULAR COMPARISON OF CONVENTIONAL PRESSURE STANDARDS USING A TRANSPORTABLE OPTICAL REFRACTOMETER: PREPARATION AND TRANSPORTATION
Using a transportable Fabry-PĂ©rot cavity refractometer, a circular comparison of existing primary standards at several national metrology institutes is currently underway. This paper provides information about the refractometer, the preparation for the comparison, and the transportation procedur
Improved theory of laser-enhanced ionization in flames: comparison with experiment
An improved theory for laser enhanced ionization in flames has been developed for oneâ and twoâstep laser excitations. The model gives an analytical expression for the sensitivity of the method for a given transition of any element. The theoretical expression is compared with experimentally measured signals for a number of elements and the agreement is found to be generally good
Isotope shift in the electron affinity of chlorine
The specific mass shift in the electron affinity between ^{35}Cl and ^{37}Cl
has been determined by tunable laser photodetachment spectroscopy to be
-0.51(14) GHz. The isotope shift was observed as a difference in the onset of
the photodetachment process for the two isotopes. In addition, the electron
affinity of Cl was found to be 29138.59(22) cm^{-1}, giving a factor of 2
improvement in the accuracy over earlier measurements. Many-body calculations
including lowest-order correlation effects demonstrates the sensitivity of the
specific mass shift and show that the inclusion of higher-order correlation
effects would be necessary for a quantitative description.Comment: 16 pages, 6 figures, LaTeX2e, amsmat
Quantum-based realizations of the pascal: status and progress of the EMPIR-project: quantumpascal
The QuantumPascal (QP) project combines the capabilities of 12 European institutions to enable traceable pressure measurements utilizing quantum-based methods that evaluate the number density instead of force per area to target the wide pressure range between 1 Pa and 3 MPa. This article summarizes the goals and results since the project start in June 201
Laser frequency stabilization based on a universal sub-Doppler NICE-OHMS instrumentation for the potential application in atmospheric lidar
Lidar is an effective tool for high-altitude atmospheric measurement in which
a weak absorption line for the target gas is selected to ensure a large
optical depth. The laser frequency stabilization to the line center is
required, and a sub-Doppler (sD) spectroscopy of the target line is preferred
as a frequency reference. In this paper, a novel universal sD noise-immune cavity-enhanced optical heterodyne molecular
spectroscopy
(NICE-OHMS)
instrumentation based on a fiber-coupled optical single-sideband
electro-optic modulator (f-SSM) for the potential application in atmospheric
lidar for different target gases with different types of lasers is reported.
The f-SSM can replace all frequency actuators in the system, so as to
eliminate the individual design of feedback servos that often are tailored
for each laser. The universality of the instrumentation was demonstrated by
the alternative use of either an Er-doped fiber laser or a whispering-gallery-mode laser. Then the instruments based on both lasers were used to produce
the sD signals of acetylene, which worked as a frequency reference to
stabilize the laser. By performing the lockings, relative frequency
stabilizations of 8.3Ă10-13 and 7.5Ă10-13 at
an integration time of 240 s were demonstrated.</p
Optical Detection of Laser Induced Ionization in the Inductively coupled Plasma for the Study of Ion-Electron Recombination and Ionization Equilibrium
Abstract not availableNA-NOT AVAILABL
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