The Expected Performance of an Optical Pumping Light Source, and the Kinetics of Optical Pumping of 23S13He

1971 ◽  
Vol 49 (5) ◽  
pp. 525-538 ◽  
Author(s):  
J. M. Daniels ◽  
R. S. Timsit
Keyword(s):  
Angular Momentum ◽  
Light Source ◽  
Optical Pumping ◽  
Light Flux ◽  
Resonance Radiation ◽  
Transition Rates ◽  
Expected Performance ◽  
Kinetics Of

A practical light source for optical pumping necessarily excites transitions other than those which it is desired should be excited. It is shown that a pumping light source for 23S13He may be characterized by three parameters, which describe the transition rates for Δm = ±1, and 0, transitions under standard conditions. Expressions are derived relating these parameters to the geometry of the light source. The equation which describes the flow of angular momentum into 3He is formulated, using these parameters, the light flux, the lifetime of the metastable atoms, and collisional mixing in the 23P states. This equation is solved to give the polarization which may be attained, and the rate at which the polarization is built up. A modification of this equation is also given, which takes into account moderate trapping of resonance radiation. An expression is also derived which relates the polarization of 3He to the intensity of the scattered pumping light.

The Polarizations Produced, and the Rates of Polarization, in the Optical Pumping of 23S13He

1971 ◽  
Vol 49 (5) ◽  
pp. 545-559 ◽  
Author(s):  
R. S. Timsit ◽  
J. M. Daniels
Keyword(s):  
Light Source ◽  
Satisfactory Agreement ◽  
Nuclear Polarization ◽  
Optical Pumping ◽  
Resonance Radiation ◽  
Metastable Atom ◽  
Circularly Polarized ◽  
Atom Density ◽  
Theoretical Predictions ◽  
Gas Pressures

The optical pumping of metastable 3He atoms with circularly polarized resonance radiation from a 4He light source has been carried out at several 3He gas pressures and at different pumping light intensities and metastable atom concentrations. The dependence of both the equilibrium nuclear polarization and the pumping time on both the metastable atom density and the intensity of the pumping radiation is in satisfactory agreement with the theoretical predictions of Daniels and Timsit.

scholarly journals Kinetics of 1- and 2-methylallyl + O2 reaction, investigated by photoionisation using synchrotron radiation

2021 ◽  
Author(s):  
Domenik Schleier ◽  
Engelbert Reusch ◽  
Marius Gerlach ◽  
Tobias Preitschopf ◽  
Deb Pratim Mukhopadhyay ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Reaction Kinetics ◽  
Molecular Oxygen ◽  
Light Source ◽  
Storage Ring ◽  
Vacuum Ultraviolet ◽  
Flow Tube ◽  
Tube Reactor ◽  
Swiss Light Source ◽  
Kinetics Of

The reaction kinetics of the isomers of the methylallyl radical with molecular oxygen has been studied in a flow tube reactor at the vacuum ultraviolet (VUV) beamline of the Swiss Light Source storage ring.

Simultaneous photochemical generation of ozone in the gas phase and photolysis of aqueous reaction systems using one VUV light source

1997 ◽  
Vol 35 (4) ◽  
pp. 41-48 ◽  
Author(s):  
T.M. Hashem ◽  
M. Zirlewagen ◽  
A. M. Braun
Keyword(s):  
Gas Phase ◽  
Light Source ◽  
Organic Pollutants ◽  
Vacuum Ultraviolet ◽  
Oxidative Degradation ◽  
Reaction System ◽  
Photochemical Reactions ◽  
Experimental Conditions ◽  
Photochemical Generation ◽  
Kinetics Of

A more efficient use of vacuum ultraviolet (VUV) radiation produced by an immersed Xe-excimer light source (172 nm) was investigated for the oxidative degradation of organic pollutants in aqueous systems. All emitted VUV radiation from one light source was used in two simultaneous but separate photochemical reactions: (1) photochemical generation of ozone by irradiating oxygen in the gas phase and (2) photolysis of the aqueous reaction system. The gas stream containing the generated ozone is sparged into the reaction system, thus enhancing the oxidative degradation of organic pollutants. The photochemically generated ozone in the gas phase was quantitatively analyzed, and the kinetics of the degradation of 4-chlorophenol (4-CP) and of the dissolved organic carbon (DOC) were determined under different experimental conditions. The results show that the rates of degradation of the substrate and of the DOC decrease in the order of the applied processes, VUV/O3 > O3 > VUV.

scholarly journals Elimination of the blinding effect in landscape luminaires

2018 ◽  
Vol 7 (2.13) ◽  
pp. 252
Author(s):  
Albert Ashryatov ◽  
Dinara Churakova
Keyword(s):  
Light Curve ◽  
Light Source ◽  
Light Flux ◽  
Light Distribution ◽  
Light Sources ◽  
Mirror Surface ◽  
Light Emitting ◽  
Lighting Technology ◽  
Initial Task ◽  
Flat Beam

The article presents one of the possible options for implementing the lighting technology "Flat beam" for landscape lighting purposes. One of the possible ways to control the light distribution of a number of light sources based on LEDs with different radiation patterns is considered. As a secondary optics, it is proposed to use a mirror surface that redistributes the light flux of an LED light source. It is indicated that, depending on the initial type of the light-emitting diodes light curve and the features of mounting the mirror surface, the resulting light distribution can vary widely, depending on the initial task that the designer sets for himself.  

Notizen: Wirkungsquerschnitte für Gleichverteilung der 62P3/2-Zustände von Cäsium durch Stöße mit gesättigten Kohlenwasserstoffen

1969 ◽  
Vol 24 (6) ◽  
pp. 1030-1031
Author(s):  
N . Fronimos ◽  
J. Fricke ◽  
J. Haas
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Selection Rule ◽  
Optical Pumping

Additional cross sections for collisionally induced mixing of the Cs-62P3/2 sublevels have been measured from optical pumping with σ+ D2-light. Using the model of a random re­orientation of the electronic angular momentum during the collision the derived cross sections are: Cs-CH4 (206±40) Å2, Cs-C2H6 (303±60) Å2, Cs-C3H8 (370 ±70) Å2. The existence of a selection rule mJ ﹘ /→ ﹘mJ would in­crease these values by a factor of 1.5.

Angular Momentum Dependence of Transition Rates in the Exciton Model

1995 ◽  
Vol 75 (12) ◽  
pp. 2284-2287 ◽  
Author(s):  
Ye. A. Bogila ◽  
V. M. Kolomietz ◽  
A. I. Sanzhur ◽  
S. Shlomo
Keyword(s):  
Angular Momentum ◽  
Momentum Dependence ◽  
Transition Rates ◽  
Exciton Model

scholarly journals Theta-modulated generation of chromatic orbital angular momentum beams from a white-light source

2016 ◽  
Vol 24 (21) ◽  
pp. 23911 ◽  
Author(s):  
Jikang Wang ◽  
Yuanying Zhang ◽  
Wuhong Zhang ◽  
Lixiang Chen
Keyword(s):  
Angular Momentum ◽  
Light Source ◽  
Orbital Angular Momentum ◽  
White Light ◽  
White Light Source

scholarly journals Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

2014 ◽  
Vol 104 (5) ◽  
pp. 054104 ◽  
Author(s):  
V. Venkatraman ◽  
S. Kang ◽  
C. Affolderbach ◽  
H. Shea ◽  
G. Mileti
Keyword(s):  
Light Source ◽  
Optical Pumping ◽  
Vapor Cell ◽  
Rb Vapor

scholarly journals Prior Compensation Algorithm for Cerenkov Luminescence Tomography From Single-View Measurements

2021 ◽  
Vol 11 ◽  
Author(s):  
Lin Wang ◽  
Xiaowei He ◽  
Jingjing Yu
Keyword(s):  
Light Source ◽  
Imaging System ◽  
Three Dimensional ◽  
Light Flux ◽  
System Matrix ◽  
Full Account ◽  
Single View ◽  
Compensation Algorithm ◽  
Detection Plane ◽  
Calibration Matrix

Cerenkov luminescence tomography (CLT) has attracted much attention because of the wide clinically-used probes and three-dimensional (3D) quantification ability. However, due to the serious morbidity of 3D optical imaging, the reconstructed images of CLT are not appreciable, especially when single-view measurements are used. Single-view CLT improves the efficiency of data acquisition. It is much consistent with the actual imaging environment of using commercial imaging system, but bringing the problem that the reconstructed results will be closer to the animal surface on the side where the single-view image is collected. To avoid this problem to the greatest extent possible, we proposed a prior compensation algorithm for CLT reconstruction based on depth calibration strategy. This method takes full account of the fact that the attenuation of light in the tissue will depend heavily on the depth of the light source as well as the distance between the light source and the detection plane. Based on this consideration, a depth calibration matrix was designed to calibrate the attenuation between the surface light flux and the density of the internal light source. The feature of the algorithm was that the depth calibration matrix directly acts on the system matrix of CLT reconstruction, rather than modifying the regularization penalty items. The validity and effectiveness of the proposed algorithm were evaluated with a numerical simulation and a mouse-based experiment, whose results illustrated that it located the radiation sources accurately by using single-view measurements.

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